LP5891
SLDS269A – MARCH 2022 – REVISED MAY 2022
LP5891 48 Current Sources, 64 Scans, Common Cathode LED Matrix Driver
1 Features
•
•
•
•
•
•
Separated VCC and VR/G/B power supply
– VCC voltage range: 2.5 V–5.5 V
– VR/G/B voltage range: 2.5 V–5.5 V
48 current source channels from 0.2 mA to 20 mA
– Channel-to-channel accuracy: ±0.5% (typ.),
±2% (max.); device-to-device accuracy: ±0.5%
(typ.), ±2% (max.)
– Low knee voltage: 0.26 V (max.) when IOUT = 5
mA
– 3-bits (8 steps) global brightness control
– 8-bits (256 steps) color brightness control
– Maximum 16-bits (65536 steps) PWM
grayscale control
16 scan line switches with 190-mΩ RDS(ON)
Ultra-low power consumption
– Independent VCC down to 2.5 V
– Lowest ICC down to 3.6 mA with 50-MHz GCLK
– Intelligent power saving mode with ICC down to
0.9 mA
Built-in SRAM to support 1–64 multiplexing
– Single device to support 48 × 16 LEDs or 16 ×
16 RGB pixels
– Dual devices stackable to support 96 × 32
LEDs or 32 × 32 RGB pixels
– Three devices stackable to support 144 × 48
LEDs or 48 × 48 RGB pixels
– Four devices stackable to support 192 × 64
LEDs or 64 × 64 RGB pixels
High speed and low EMI Continuous Clock Series
Interface (CCSI)
– Only three wires: SCLK / SIN / SOUT
– External 50-MHz (max.) SCLK with rising-edge
transmission mechanism
•
•
– Internal frequency multiplier to support high
frequency GCLK
Optimized performances for LED matrix displays
– Upside and downside ghosting removal
– Low grayscale enhancement
– LED open, weak-short, short detection and
removal
LP5891MRRFR supports –55°C to approximately
125°C operating ambient temperature
2 Applications
•
•
•
•
Mini- / micro-LED matrix products
Gaming keyboard RGB LED backlighting
Audio mixer, DJ equipment, and broadcast
LED luminous panel and Local dimming backlight
3 Description
The LP5891 is a highly integrated, common-cathode
LED matrix driver with 48 constant current sources
and 16 scanning FETs. The LP5891 implements
a high speed rising-edge transmission interface
to support high device count daisy-chained while
minimizing electrical-magnetic interference (EMI) and
internal GCLK rate ranges from 40 MHz to 160 MHz.
The device also implements LED open/weak-short/
short detections and removals during operations.
Device Information
PART NUMBER
LP5891
(1)
PACKAGE(1)
BODY SIZE (NOM)
VQFN(76)
9 mm × 9 mm
BGA(96)
6 mm × 6 mm
For all available packages, see the orderable addendum at
the end of the data sheet.
LP5891 with Four Devices Stackable Connection
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
Table of Contents
1 Features............................................................................1
2 Applications..................................................................... 1
3 Description.......................................................................1
4 Revision History.............................................................. 2
5 Pin Configuration and Functions...................................3
6 Specifications.................................................................. 5
6.1 Absolute Maximum Ratings........................................ 5
6.2 ESD Ratings............................................................... 5
6.3 Recommended Operating Conditions.........................5
6.4 Thermal Information....................................................5
6.5 Electrical Characteristics.............................................6
6.6 Timing Requirements.................................................. 9
6.7 Switching Characteristics............................................9
6.8 Typical Characteristics.............................................. 10
7 Detailed Description......................................................12
7.1 Overview................................................................... 12
7.2 Functional Block Diagram......................................... 12
7.3 Feature Description...................................................13
7.4 Device Functional Modes..........................................25
7.5 Continuous Clock Series Interface............................25
7.6 PWM Grayscale Control........................................... 31
7.7 Register Maps...........................................................34
8 Application and Implementation.................................. 49
8.1 Application Information............................................. 49
8.2 Typical Application.................................................... 49
9 Power Supply Recommendations................................57
10 Layout...........................................................................58
10.1 Layout Guidelines................................................... 58
10.2 Layout Example...................................................... 58
11 Device and Documentation Support..........................62
11.1 Documentation Support ......................................... 62
11.2 Receiving Notification of Documentation Updates.. 62
11.3 Support Resources................................................. 62
11.4 Trademarks............................................................. 62
11.5 Electrostatic Discharge Caution.............................. 62
11.6 Glossary.................................................................. 62
12 Mechanical, Packaging, and Orderable
Information.................................................................... 63
4 Revision History
Changes from Revision * (March 2022) to Revision A (May 2022)
Page
• First public release..............................................................................................................................................1
• Updated the Stackable Mode section............................................................................................................... 13
• Updated Figure 7-8 ..........................................................................................................................................18
• Changed several field bits in the FC0 register table and Fields Description table............................................35
• Changed the name COLOR_R/G/B to LG_COLOR_R/G/B in the FC2 register table for better understanding...
39
• Changed the name of bit 7 to bit 0 in the FC3 register table for better understanding..................................... 41
• Deleted some words in the SCAN_REV field description.................................................................................43
2
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
Line3
Line4
Line5
Line6
Line7
Line8
Line9
Line10
Line11
Line12
Line13
Line14
Line15
SCLK
SIN
SOUT
71
70
69
68
67
66
65
64
63
62
61
60
59
58
Line2
74
72
Line1
75
73
Line0
76
5 Pin Configuration and Functions
R0
1
57
R15
G0
2
56
G15
B0
3
55
B15
R1
4
54
R14
G1
5
53
G14
B1
6
52
B14
GND
7
51
VG
VCC
8
50
VG
VR
9
49
VB
VR
10
48
VB
R2
11
47
R13
G2
12
46
G13
B2
13
45
B13
R3
14
44
R12
G3
15
43
G12
B3
16
42
B12
R4
17
41
R11
G4
18
40
G11
B4
19
39
B11
35
36
37
38
B10
G10
R10
34
G9
R9
33
B9
32
R8
30
B8
31
29
B7
G8
28
27
R7
G7
26
B6
25
G6
23
B5
24
22
G5
R6
21
R5
IREF
20
GND
Figure 5-1. LP5891 RRF Package 76-Pin VQFN With Exposed Thermal Pad Top View
1
2
3
4
5
6
7
8
9
10
11
A
L3
L4
L5
L6
L7
L8
L9
L10
L11
L12
L13
B
L2
R1
B0
G0
R0
NC
SOU
T
SIN
SCL
K
NC
L14
C
L1
G1
GND
L15
D
L0
B1
E
GND
GND
F
VCC
G
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
R15
R14
VG
R2
R3
GND
GND
GND
G15
G14
VG
VR
G2
G3
GND
GND
GND
B15
B14
VB
H
VR
B2
B3
R7
B8
B9
B10
R13
VB
J
IREF
R4
G13
B13
K
G4
B4
R6
G6
G7
G8
G9
G10
B11
R12
G12
L
R5
G5
B5
B6
B7
R8
R9
R10
G11
R11
B12
Figure 5-2. LP5891 ZXL Package 96-Pin BGA Top View
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
3
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
Table 5-1. Pin Functions
PIN
NAME
IREF
VCC
4
I/O
DESCRIPTION
RRF NO.
ZXL NO.
20
J1
I
Pin for setting the maximum constant-current value. Connecting an external
resistor between IREF and GND sets the maximum current for each constantcurrent output channel. When this pin is connected directly to GND, all outputs
are forced off. The external resistor must be placed close to the device.
8
F1
I
Device power supply
VR
9, 10
G1, H1
I
Red LED power supply
VG
51, 50
E11, F11
I
Green LED power supply
VB
49, 48
G11, H11
I
Blue LED power supply
R0-R15
1, 4, 11, 14, B5, B2,F2, F4,
17, 21, 24, J2, L1, K3, H5,
27, 32, 35, L6, L7, L8, L10,
38, 41, 44, K10, H10, E10,
47, 54, 57
E8
O
Red LED constant-current output
G0-G15
2, 5, 12, 15, B4, C2, G2, G4,
18, 22, 25, K1, L2, K4, K5,
28, 31, 34, K6, K7, K8, L9,
37, 40, 43, K11, J10, F10,
46, 53, 56
F8
O
Green LED constant-current output
B0-B15
3, 6, 13, 16, B3, D2, H2, H4,
19, 23, 26, K2, L3, L4, L5,
29, 30, 33, H6, H7, H8, K9,
36, 39, 42, L11, J11, G10,
45, 52, 55
G8
O
Blue LED constant-current output
LINE0LINE15
76, 75, 74,
73, 72, 71,
70, 69, 68,
67, 66, 65,
64, 63, 62,
61
D1, C1, B1, A1,
A2, A3, A4, A5,
A6, A7, A8, A9,
A10, A11, B11,
C11
O
Scan lines
SCLK
60
B9
I
Clock-signal input pin
SIN
59
B8
I
Serial-data input pin
SOUT
58
B7
O
Serial data output pin
GND
7
C10, E1, E2,
D5, D6, D7, D8,
D10, D11,
E1,E2, E4, E5,
E6,E7, F5, F6,
F7,G5, G6, G7
—
Power-ground reference
Thermal
pad
—
—
—
The thermal pad and the GND pin must be connected together on the board
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
6 Specifications
6.1 Absolute Maximum Ratings
over operating free-air temperature range (unless otherwise noted)(1)
MIN
MAX
UNIT
VCC
–0.3
6
V
VR/G/B
–0.3
6
V
IREF, SCLK, SIN, SOUT
–0.3
6
V
RX/GX/BX
–0.3
6
V
LINE0 to LINE15
–0.3
6
V
Operating junction temperature, TJ , LP5891RRFR and LP5891ZXLR
–40
150
°C
Operating junction temperature, TJ, LP5891MRRFR
–55
150
°C
Storage temperature, Tstg
–55
150
°C
Voltage
(1)
Operation outside the Absolute Maximum Ratings may cause permanent device damage. Absolute Maximum Ratings do not imply
functional operation of the device at these or any other conditions beyond those listed under Recommended Operating Conditions.
If used outside the Recommended Operating Conditions but within the Absolute Maximum Ratings, the device may not be fully
functional, and this may affect device reliability, functionality, performance, and shorten the device lifetime.
6.2 ESD Ratings
VALUE
V(ESD)
(1)
(2)
Electrostatic discharge
Human-body model (HBM), per ANSI/ESDA/JEDEC
JS-001(1)
UNIT
±4000
Charged device model (CDM), per ANSI/ESDA/JEDEC JS-002(2)
V
±1000
JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process.
JEDEC document JEP157 states that 250-V CDM allows safe manufacturing with a standard ESD control process.
6.3 Recommended Operating Conditions
over operating free-air temperature range (unless otherwise noted)
MIN
VCC
Device supply voltage
VLEDR/G/B
LED supply voltage
VIH
High level logic input voltage (SCLK, SIN)
VIL
Low level logic input voltage (SCLK, SIN)
IOH
High level logic output current (SOUT)
IOL
Low level logic output current (SOUT)
ICH
Constant output source current
ILINE
Line scan switch load current
TA
Ambient operating temperature (LP5891RRFR and LP5891ZXLR)
TA
Ambient operating temperature (LP5891MRRFR)
NOM
MAX
UNIT
2.5
5.5
V
2.5
5.5
V
0.7 × VCC
V
0.3 × VCC
V
–2
mA
2
mA
0.2
20
mA
0
2
A
–40
85
°C
–55
125
°C
6.4 Thermal Information
LP5891
THERMAL METRIC(1)
RRF (VQFN)
ZXL (BGA)
UNIT
76 PINS
96 PINS
RθJA
Junction-to-ambient thermal resistance
22.2
33.5
°C/W
RθJC(top)
Junction-to-case (top) thermal resistance
10.7
18.6
°C/W
RθJB
Junction-to-board thermal resistance
7.2
11.7
°C/W
ψJT
Junction-to-top characterization parameter
0.1
0.3
°C/W
ψJB
Junction-to-board characterization parameter
7.1
11.6
°C/W
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
5
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
LP5891
THERMAL METRIC(1)
RθJC(bot)
(1)
RRF (VQFN)
ZXL (BGA)
76 PINS
96 PINS
Junction-to-case (bottom) thermal resistance
UNIT
1.7
°C/W
For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application
report.
6.5 Electrical Characteristics
At VCC = VR = 2.8 V, VG/B = 3.8 V, TA = –40°C to +85°C for LP5891RRFR and LP5891ZXLR while TA = –40°C to +125°C for
LP5891MRRFR; Typical values are at TA = 25°C (unless otherwise specified)
PARAMETER
Device supply voltage
VUVR
Undervoltage restart
VCC rising
VUVF
Undervoltage shutdown
VCC falling
VUV(HYS)
Undervoltage shutdown
hysteresis
ICC
6
TEST CONDITIONS
VCC
Device supply current
MIN
TYP
2.5
MAX
UNIT
5.5
V
2.3
V
2.0
V
0.1
V
SCLK/SIN = 10 MHz,
MPSM_EN=1bit, Matrix PSM enable,
internal GCLK off, GSn = 0000h, BC
= 2h, CCR/G/B = 63h, PS_EN= 1h,
VOUTn = floating, RIREF = 7.8 kΩ (In
intelligent power save mode)
0.9
mA
SCLK/SIN = 10 MHz, Standby
enable, internal GCLK off, GSn =
0000h, BC = 2h, CCR/G/B = 63h,
PS_EN= 1h, VOUTn = floating,
RIREF = 7.8 kΩ (In intelligent power
save mode)
0.9
mA
SCLK/SIN = 10 MHz,
PSP_MOD=1bit, internal
GCLK=50MHz, GSn = 0000h, BC =
2h, CCR/G/B = 63h, PS_EN= 1h,
VOUTn = floating, RIREF = 7.8 kΩ (In
power save mode)
3.6
mA
SCLK = 10 MHz, internal GCLK =
50 MHz, GSn = 1FFFh, BC = 2h,
CCR/G/B = 63h,VOUTn = floating,
RIREF = 7.8 kΩ, ICH = 2 mA
3.6
mA
SCLK = 10 MHz, internal GCLK =
100 MHz, GSn = 1FFFh, BC = 2h,
CCR/G/B = 63h, VOUTn = floating,
RIREF = 7.8 kΩ, ICH = 2 mA
4.9
mA
VR/G/B
LED supply voltage
2.5
5.5
VIH
High level input voltage (SCLK,
SIN)
VIL
Low level input voltage (SCLK,
SIN)
VOH
High level output voltage (SOUT) IOH = –2 mA at SOUT
VOL
Low level output voltage (SOUT) IOL = 2 mA at SOUT
ILOGIC
Logic pin current (SCLK, SIN)
SCLK/SIN = VCC or GND
RDS(ON)
Scan switches' on-state
resistance (LINE0 to LINE15)
VCC = 2.8 V, TA= 25°C
190
mΩ
VIREF
Reference voltage
SCLK/SIN = GND, internal GCLK=
0MHz, GSn = 0000h, BC = 2h,
CCR/G/B = 63h, VOUTn = floating,
RIREF = 7.8 kΩ
0.8
V
0.7 × VCC
Submit Document Feedback
V
V
VCC-0.4
-1
0.3 × VCC
V
VCC
V
0.4
V
1
uA
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
6.5 Electrical Characteristics (continued)
At VCC = VR = 2.8 V, VG/B = 3.8 V, TA = –40°C to +85°C for LP5891RRFR and LP5891ZXLR while TA = –40°C to +125°C for
LP5891MRRFR; Typical values are at TA = 25°C (unless otherwise specified)
PARAMETER
VKNEE
ICH(LKG)
ΔIERR(CC)
Channel knee voltage (R0-R15 /
G0-G15 / B0-B15)
Channel leakage current (R0R15 / G0-G15 / B0-B15)
Constant-current channel to
channel deviation (R0-R15 / G0G15 / B0-B15)(1)
MAX
UNIT
VLEDR/G/B ≥ 2.8 V, all channel
outputs on, output current at 1 mA
TEST CONDITIONS
MIN
TYP
0.25
V
VLEDR/G/B ≥ 2.8 V, all channel
outputs on, output current at 5 mA
0.26
V
VLEDR/G/B ≥ 2.8 V, all channel
outputs on, output current at 10 mA
0.3
V
VLEDR/G/B ≥ 2.8 V, IMAX = 1b, all
channel outputs on, output current at
15 mA
0.37
V
VLEDR/G/B ≥ 2.8 V, IMAX=1b, all
channel outputs on, output current at
20 mA
0.41
V
1
uA
Channel voltage at 0 V
All CHn = on, BC = 00h, CC =
31h, VOUTn = (VLED-1)V, RIREF =
19.05 kΩ (ICH = 0.2-mA target), TA =
25°C, includes the VIREF tolerance,
at same color grouped outputs of
R0-R15 / G0-G15 / B0-B15
±1
±2.5
%
All CHn = on, BC = 00h, CC =
7Dh, VOUTn = (VLED-1)V, RIREF =
19.05 kΩ (ICH = 0.5-mA target), TA =
25°C, includes the VIREF tolerance,
at same color grouped outputs of
R0-R15 / G0-G15 / B0-B15
±0.5
±1.5
%
All CHn = on, BC = 00h, CC =
FBh, VOUTn = (VLED-1)V, RIREF =
19.05 kΩ (ICH = 1-mA target), TA =
25°C, includes the VIREF tolerance,
at same color grouped outputs of
R0-R15 / G0-G15 / B0-B15
±0.5
±1.5
%
All CHn = on, BC = 2h, CC =
FBh, VOUTn = (VLED-1)V, RIREF =
7.8 kΩ (ICH = 5-mA target), TA =
25°C, includes the VIREF tolerance,
at same color grouped outputs of
R0-R15 / G0-G15 / B0-B15
±0.5
±2
%
All CHn = on, BC = 6h, CC =
A7h, VOUTn = (VLED-1)V, RIREF =
7.8 kΩ (ICH = 10-mA target), TA =
25°C, includes the VIREF tolerance,
at same color grouped outputs of
R0-R15 / G0-G15 / B0-B15
±0.5
±2
%
All CHn = on, BC = 7h, CC = FBh,
IMAX=1b, VOUTn = (VLED-1)V,
RIREF = 6.8 kΩ (ICH = 20-mA target),
TA = 25°C, includes the VIREF
tolerance, at same color grouped
outputs of R0-R15 / G0-G15 / B0B15
±0.5
±2.5
%
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
7
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
6.5 Electrical Characteristics (continued)
At VCC = VR = 2.8 V, VG/B = 3.8 V, TA = –40°C to +85°C for LP5891RRFR and LP5891ZXLR while TA = –40°C to +125°C for
LP5891MRRFR; Typical values are at TA = 25°C (unless otherwise specified)
PARAMETER
ΔIERR(DD)
Constant-current device to
device deviation (R0-R15 / G0G15 / B0-B15)(2)
TYP
MAX
UNIT
All CHn = on, BC = 00h, CC =
31h, VOUTn = (VLED-1)V, RIREF =
19.05 kΩ (ICH = 0.2-mA target), TA =
25°C, includes the VIREF tolerance,
at same color grouped outputs of
R0-R15 / G0-G15 / B0-B15
TEST CONDITIONS
MIN
±1
±2.5
%
All CHn = on, BC = 00h, CC =
7Dh, VOUTn = (VLED-1)V, RIREF =
19.05 kΩ (ICH = 0.5-mA target), TA =
25°C, includes the VIREF tolerance,
at same color grouped outputs of
R0-R15 / G0-G15 / B0-B15
±0.5
±1.5
%
All CHn = on, BC = 00h, CC =
FBh, VOUTn = (VLED-1)V, RIREF =
19.05 kΩ (ICH = 1-mA target), TA =
25°C, includes the VIREF tolerance,
at same color grouped outputs of
R0-R15 / G0-G15 / B0-B15
±0.5
±1
%
All CHn = on, BC = 2h, CC =
FBh, VOUTn = (VLED-1)V, RIREF =
7.8 kΩ (ICH = 5-mA target), TA =
25°C, includes the VIREF tolerance,
at same color grouped outputs of
R0-R15 / G0-G15 / B0-B15
±0.5
±1.5
%
All CHn = on, BC = 6h, CC =
A7h, VOUTn = (VLED-1)V, RIREF =
7.8 kΩ (ICH = 10-mA target), TA =
25°C, includes the VIREF tolerance,
at same color grouped outputs of
R0-R15 / G0-G15 / B0-B15
±0.5
±2
%
All CHn = on, BC = 7h, CC = FBh,
IMAX=1b, VOUTn = (VLED-1)V,
RIREF = 6.8 kΩ (ICH = 20-mA target),
TA = 25°C, includes the VIREF
tolerance, at same color grouped
outputs of R0-R15 / G0-G15 / B0B15
±0.5
±2
%
ΔIREG(LINE)
Line regulation (R0-R15 / G0G15 / B0-B15)(3)
VLED = 2.5 to 5.5V, All CHn =
on, VOUTn = (VLED-1)V, at same
color grouped outputs of R0-R15 /
G0-G15 / B0-B15
±1
%/V
ΔIREG(LOAD)
Load regulation (R0-R15 / G0G15 / B0-B15)(4)
VOUTn = (VLED-1)V to (VLED-3)V,
VR=VG/B=VLED=3.8V, All CHn =
on, at same color grouped outputs of
R0-R15 / G0-G15 / B0-B15
±1
%/V
TTSD
Thermal shutdown threshold
170
°C
THYS
Thermal shutdown hysteresis
15
°C
(1)
The deviation of each output in same color group (OUTR0-15 or OUTG0-15 or OUTB0-15) from the average of same color group
¿:%; = N +
:0
(2)
8
+:J
F 1O × 100
+ +:1 + ® + +:14 + +:15
16
constant current. The deviation is calculated by the formula. (X = R or G or B, n = 0-15)
spacer
The deviation of the average of constant-current in each color group from the ideal constant-current value. (X = R or G or B) :
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
LP5891
www.ti.com
¿:%; = N
SLDS269A – MARCH 2022 – REVISED MAY 2022
+:0 + +:1 + ® + +:14 + +:15
F Ideal Output Current
16
O × 100
Ideal Output Current
++&'#._4(KN ) KN $)
Ideal current is calculated by the following equation:
8+4'(
1 + %%_4(KN %%_) KN %%_$)
=
× )#+0($%) ×
4+4'(
256
spacer
Line regulation is calculated by the following equation. (X = R or G or B, n = 0-15):
IXn at VLED = 5.5 V − IXn at VLED = 2.5 V
100
∆ %V =
×
5.5 V − 2.5 V
IXn at VLED = 2.5 V
(3)
spacer
Load regulation is calculated by the following equation. (X = R or G or B, n = 0-15):
IXn at VXn = 1 V − IXn at VXn = 3 V
∆ %V =
× 3 V100
− 1 V
IXn at VXn = 3 V
(4)
spacer
6.6 Timing Requirements
At VCC = VR = 2.8 V, VG/B = 3.8 V, TA = –40°C to +85°C for LP5891RRFR and LP5891ZXLR while TA = –40°C to +125°C for
LP5891MRRFR; Typical values are at TA = 25°C (unless otherwise specified)
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
50
MHz
fSCLK
Clock frequency (SCLK)
tw(H0)
High level pulse duration (SCLK)
9
ns
tw(L0)
Low level pulse duration (SCLK)
9
ns
tsu(0)
Set-up time
SIN to SCLK↑
10
ns
th(0)
Hold time
SCLK↑ to SIN↑↓
2
ns
6.7 Switching Characteristics
At VCC = VR = 2.8 V, VG/B = 3.8 V, TA = –40°C to +85°C for LP5891RRFR and LP5891ZXLR while TA = –40°C to +125°C for
LP5891MRRFR; Typical values are at TA = 25°C (unless otherwise specified)
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
tr
Rise time (SOUT)
VCC = 3.3 V, CSOUT = 30 pF
2
10
ns
tf
Fall time (SOUT)
VCC = 3.3 V, CSOUT = 30 pF
2
10
ns
tpd(0)
Propagation delay
SCLK↑ to SOUT↑↓, full temperature,
CSOUT = 30 pF
14.2
ns
3.5
(1). Input pulse rise and fall time is 2 ns typically.
Figure 6-1. Timing and Switching Diagram
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
9
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
6.8 Typical Characteristics
0.016
0.016
0.2 mA
1 mA
5 mA
10 mA
15 mA
Output Current (A)
0.012
0.2 mA
1 mA
5mA
10 mA
15 mA
0.014
0.012
Output Current (A)
0.014
0.01
0.008
0.006
0.01
0.008
0.006
0.004
0.004
0.002
0.002
0
0
0
0.2
0.4
0.6
0.8
1
1.2
VLED - VCH (V)
1.4
1.6
1.8
2
0
Vcc = 2.8 V
0.4
0.6
11
1.6
1.8
2
1.7
8
Constant Current Accuracy (%)
9
7
6
5
4
3
2
1.1
0.5
-0.1
-0.7
125oC Min
85oC Min
25oC Min
-40oC Min
-55oC Min
-1.3
-1.9
1
125oC Max
85oC Max
25oC Max
-40oC Max
-55oC Max
-2.5
0
0
0.2
0.4
0.6
0.8
1
1.2
VLED - VCH (V)
1.4
1.6
1.8
0
2
Figure 6-4. Channel Current vs. (VLED-Vchannel) Voltage
2
4
6
8
10
12
14
Output Current (mA)
16
18
20
Figure 6-5. Channel to Channel Accuracy vs Output Current
0.012
0.016
0.2 mA, BC = 00h
1 mA, BC = 02h
5 mA, BC = 02h
10 mA, BC = 06h
15 mA, BC = 06h
0.014
0.012
0.011
0.01
0.009
0.01
Icc (A)
Output Current (A)
1.4
Figure 6-3. Channel Current vs (VLED-Vchannel) Voltage
-55oC
-40oC
25oC
85oC
125oC
10
0.008
0.006
0.008
0.007
0.006
0.004
0.005
0.002
0.004
0
0
30
60
90
120
150
180
210
Color Control Code (Decimal)
240
Figure 6-6. Color Control Code vs Output Current
10
0.8
1
1.2
VLED - VCH (V)
Vcc = 5.5 V
Figure 6-2. Channel Current vs (VLED-Vchannel) Voltage
Output Current (mA)
0.2
270
0.003
40
60
80
100
120
140
GCLK Frequency (MHz)
160
180
Figure 6-7. Icc Current vs GCLK Frequency
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
6.8 Typical Characteristics (continued)
4.68
4.66
4.64
Icc (mA)
4.62
4.6
4.58
4.56
4.54
4.52
2.4
2.6
2.8
3
3.2 3.4 3.6 3.8
Vcc Voltage (V)
4
4.2
4.4
4.6
GCLK = 80 MHz
Figure 6-8. Icc Current vs Vcc Voltage
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
11
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
7 Detailed Description
7.1 Overview
The LP5891 is a highly integrated RGB LED driver with 48 constant current sources and 16 scanning FETs. A
single LP5891 is capable of driving 16 × 16 RGB LED pixels while stacking four LP5891 devices can drive 64 ×
64 RGB LED pixels. To achieve low power consumption, the device supports separated power supplies for the
red, green, and blue LEDs by its common cathode structure. Furthermore, the operation power of the LP5891
is significantly reduced by ultra-low operation voltage range (VCC down to 2.5 V) and ultra-low operation current
(ICC down to 3.6 mA).
The LP5891 supports 0.2 mA to 20 mA per channel with typical 0.5% channel-to-channel current deviation and
typical 0.5% device-to-device current deviation. The DC current value of all 48 channels is set by an external
IREF resistor and can be adjusted by the 8-step global brightness control (BC) and the 256-step per-color group
brightness control (CC_R/CC_G/CC_B).
The LP5891 implements a high speed rising-edge transmission interface to support high device count daisychained and high refresh rate while minimizing electrical-magnetic interference (EMI). The LP5891 supports up
to 50-MHz SCLK (external) and up to 160-MHz GCLK (internal).
The LP5891 also implements LED open, weak-short, and short detections and can also report this information
out to the accompanying digital processor.
7.2 Functional Block Diagram
VB VG VR
VCC
Internal LDO
TSD
Power Save
Bandgap
UVLO
R0
G0
IREF
3-Bits
Brightness control
R/G/B 8-Bits
Color control
B0
Channel
Drivers
GND
Channel
Control
Frequency
Multiplier
G15
Digital
Core
SCLK
R15
Frame
Control
B15
SIN
Line
Control
SRAM
Line Drivers
LED Short Detection
Pre-discharge
LED Open Detection
Low Grayscale
Compensation
SOUT
Line Clamp
GND
LINE15
12
LINE0
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
7.3 Feature Description
7.3.1 Independent and Stackable Mode
The LP5891 can operate in two different modes: independent or stackable. In independent mode, a single
LP5891 can drive a 16 × 16 RGB LED matrix, while in stackable mode, up to four LP5891 devices can be
stacked together, which means the line switches of one device can be shared to the others. Stacking three
LP5891 devices can drive a 48 × 48 RGB LED matrix while stacking four LP5891 devices can drive a 64 × 64
RGB matrix. The mode can be configured by the MOD_SIZE (see FC2 for more details).
7.3.1.1 Independent Mode
Figure 7-1 shows an implementation of a 16 × 32 RGB LED matrix using two LP5891 devices in independent
mode. Each device is responsible for its own 16 ×16 RGB LED matrix, which means that all the data for section
A is stored in device 1 and the data for section B is stored in device 2.
Figure 7-1. Two Devices in Independent Mode
The unused line must be assigned to the last several lines of the device. For example, if there are only 14
scanning lines, then the two unused lines must be assigned to 1_LS14 and 1_LS15.
7.3.1.2 Stackable Mode
While operating the LP5891 in stackable mode, as shown in below table.
Table 7-1. Stackable Mode
Mode
Matrix Size
Register Value
Scan Sequence
Mode1
16x32
000b
D1, D2 independent
Mode2
32x32
001b
D1->D2
Mode3
48x48
010b
D1->D2->D3
Mode4
48x48
011b
D1->D3->D2
Mode5
48x64
100b
D1->D2->D3
Mode6
48x64
101b
D1->D3->D2
Mode7
64x64
110b
D1->D2->D3->D4
Mode8
64x64
111b
D1->D4->D2->D3
Figure 7-2 device 2 needs to be rotated 180o relative to device 1. This action allows the position of line switches
to be near the center column of the LED matrix for better routing. For device 1, the lines connect sequentially
(line switch 0 connected to scan line 1). However on device 2, it is connected in reverse order, with the 16th scan
line is connected to line switch 15 and the 32nd scan line is connected to line switch 0.
Figure 7-2 shows the connection between two LP5891 devices in stackable mode driving 32 × 32 RGB LED
pixels. The MOD_SIZE must be configured to 001b. Device 1 supplies 16 line switches for the first 16 scan line,
and device 2 supplies 16 line switches for scan line 17-32. The data for matrix sections A and C are stored in
device 1, while matrix sections B and D data are stored in device 2.
To make sure the scanning sequence is still from 1st line to 32nd line, the scan line switching order of the second
device must be reversed, which can be configured by the SCAN_REV (see FC4 for more details).
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
13
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
Physical Line0
A
1_LS0
B
...
...
Device1
32 Lines
1_LS15
Physical Line15
Physical Line16
C
D
2_LS15
...
...
Device2
2_LS0
Physical Line31
32 RGBs
Figure 7-2. Mode2 Diagram
Figure 7-3. Mode3 and Mode4 Diagram
Figure 7-4. Mode5 and Mode6 Diagram
14
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
Figure 7-5. Mode7 and Mode8 Diagram
When two or more LP5891 devices are used in stackable mode, if there are unused line switches, these unused
line switches must be the last line switches of the first or the second device. For example, if there are only 30
scanning lines, and if,
SCAN_REV = '0'b, the unused line switches can be either of the below,
• 1_LS14, 1_LS15
• 2_LS14, 2_LS15
SCAN_REV = '1'b, the unused line switches can be either of below,
• 1_LS14, 1_LS15
• 2_LS1, 2_LS0
The unused line switches must be 2_LS14, 2_LS15 if SCAN_REV = '0'b, or 2_LS1, 2_LS0 if SCAN_REV = '1'b.
7.3.2 Current Setting
7.3.2.1 Brightness Control (BC) Function
The LP5891 device is able to adjust the output current of all constant-current outputs simultaneously. This
function is called global brightness control (BC). The global BC for all outputs is programmed with a 3-bit
register, thus all output currents can be adjusted in eight steps for a given current-programming resistor, RIREF.
When the 3-bit BC register changes, the gain of output current, GAINBC changes as Table 7-2 below.
Table 7-2. Current Gain Versus BC Code
BC Register (BC)
Current Gain (GAINBC)
000b
24.17
001b
30.57
010b
49.49
011b (default)
86.61
100b
103.94
101b
129.92
110b
148.48
111b
173.23
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
15
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
The maximum output current per channel, IOUTSET, is determined by resistor R IREF, and the GAINBC. The voltage
on IREF is typically 0.8 V. RIREF can be calculated by Equation 1 below. For noise immunity purpose, suggest
RIREF < 40 kΩ.
4+4'( (G×) =
8+4'( (8)
8+4'( (8)
=
× )#+0($%)
++4'( (I#) +1765'6 (I#)
(1)
7.3.2.2 Color Brightness Control (CC) Function
The LP5891 device is able to adjust the output current of each of the three color groups R0-R15, G0-G15, and
B0-B15 separately. This function is called color brightness control (CC). For each color, it has 8-bit data register,
CC_R, CC_G, or CC_B. Thus, all color group output currents can be adjusted in 256 steps from 0% to 100%
of the maximum output current, IOUTSET. The output current of each color, IOUT_R (or G or B) can be calculated by
Equation 2 below.
+176 _4(KN ) KN $) = +1765'6 ×
1 + %%_4(KN %%_) KN %%_$)
256
(2)
Table Table 7-3 shows the CC data versus the constant-current against IOUTSET:
Table 7-3. CC Data vs Current Ratio
CC Register (CC_R or CC_G or
CC_B)
Ratio of IOUTSET
0000 0000b
1/256
0.39%
0000 0001b
2/256
0.78%
...
...
...
0111 1111b (default)
128/256
50%
...
...
...
1111 1110b
255/256
99.61%
1111 1111b
256/256
100%
7.3.2.3 Choosing BC/CC for a Different Application
BC is mainly used for global brightness adjustment to adapt to ambient brightness, such as between day and
night, indoor and outdoor.
• Suggested BC is 3h or 4h, which is in the middle of the range, allowing flexible changes in brightness up and
down.
• If the current of one color group (usually R LEDs) is close to the output maximum current (10 mA or 20
mA), to prevent the constant output current from exceeding the upper limit in case a larger BC code is input
accidentally, choose the maximum BC value, 7h.
• If the current of one color group (usually B LEDs) is close to the output minimum current (0.2 mA), to prevent
the constant output current from exceeding the lower limit in case a lower BC code is input accidentally,
choose the minimum BC code, 0h.
CC can be used to fine tune the brightness in 256 steps. This is suitable for white balance adjustment between
RGB color group. To get a pure white color, the general requirement for the luminous intensity ratio of R, G,
B LED is 5:3:2. Depending on the characteristics of the LED (Electro-Optical conversion efficiency), the current
ratio of R, G, B LED is much different from this ratio. Usually, the Red LED needs the largest current. Choose
255d (the maximum value) CC code for the color group that needs the largest initial current, then choose proper
CC code for the other two color groups according to the current ratio requirement of the LED used.
7.3.3 Frequency Multiplier
The LP5891 has an internal frequency multiplier to generate the GCLK by SCLK. The GCLK frequency can be
configured by FREQ_MOD (See FC0 for more details) and FREQ_MUL (see FC0 for more details ) from 40 MHz
to 160 MHz. As Figure 7-6 shows, if the GCLK frequency is not higher than 80 MHz, the GCLK_MOD is set
16
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
to 0 to disable the bypass switch (enable the ½ divider), while the GCLK frequency is higher than 80 MHz, the
GCLK_MOD is set to 1 to enable the bypass switch (disable the ½ divider).
GCLK_MUL
GCLK_MOD
SCLK
GCLK
1/2
Figure 7-6. Frequency Multiplier Block Diagram
7.3.4 Line Transitioning Sequence
The LP5891 defines a timing sequence of scan line transition, shown as Figure 7-7. T_SW is the total
transitioning time. T_SW is broken up into four intervals: T0 is the time interval between the end of PWM time
in current segment and the beginning of channel pre-discharge, T1 is the time interval between the beginning
of the channel pre-discharge and the beginning of current line OFF, T2 is the time interval that the beginning of
current line OFF and the beginning of next line ON, T3 is the time interval of the beginning of next line ON and
the beginning of PWM time in next segment.
Figure 7-7. Line Transitioning Sequence
The line switch time T_SW equals to T0 + T1 + T2 + T3. T_SW can be configured by the LINE_SWT (see FC1
register bit 40-37 in Table 7-8).
Table 7-4 is the relation between LINE_SWT bits and the line switch time (GCLK numbers) with different internal
GCLK frequency.
Table 7-4. Line Switch Time
LINE_SW
T
GCLK
Numbers
T_SW (us, 40
MHZ GCLK)
T_SW (us, 60 MHZ
GCLK)
T_SW (us, 100 MHZ T_SW (us, 120 MHZ T_SW (us, 160 MHZ
GCLK)
GCLK)
GCLK)
0000b
45
1.125
0.7515
0.45
0.3735
0.2835
0001b
60
1.5
1.002
0.6
0.498
0.378
0010b
90
2.25
1.503
0.9
0.747
0.567
0011b
120
3
2.004
1.2
0.996
0.756
0100b
150
3.75
2.505
1.5
1.245
0.945
0101b
180
4.5
3.006
1.8
1.494
1.134
0110b
210
5.25
3.507
2.1
1.743
1.323
0111b
240
6
4.008
2.4
1.992
1.512
1000b
270
6.75
4.509
2.7
2.241
1.701
1001b
300
7.5
5.01
3
2.49
1.89
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
17
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
Table 7-4. Line Switch Time (continued)
LINE_SW
T
GCLK
Numbers
T_SW (us, 40
MHZ GCLK)
T_SW (us, 60 MHZ
GCLK)
T_SW (us, 100 MHZ T_SW (us, 120 MHZ T_SW (us, 160 MHZ
GCLK)
GCLK)
GCLK)
1010b
330
8.25
5.511
3.3
2.739
2.079
1011b
360
9
6.012
3.6
2.988
2.268
1100b
390
9.75
6.513
3.9
3.237
2.457
1101b
420
10.5
7.014
4.2
3.486
2.646
1110b
450
11.25
7.515
4.5
3.735
2.835
1111b
480
12
8.016
4.8
3.984
3.024
7.3.5 Protections and Diagnostics
7.3.5.1 Thermal Shutdown Protection
The thermal shutdown (TSD) function turns off all IC constant-current outputs when the junction temperature (TJ)
exceeds 170°C (typical). The function resumes normal operation when TJ falls below 155°C (typical).
7.3.5.2 IREF Resistor Short Protection
The IREF resistor short protection (ISP) function prevents unwanted large currents from flowing through the
constant-current output when the IREF resistor is shorted accidently. The LP5891 device turns off all output
channels when the IREF pin voltage is lower than 0.19 V (typical). When the IREF pin voltage goes higher than
0.325 V (typical), the LP5891 device resumes normal operation.
7.3.5.3 LED Open Load Detection and Removal
7.3.5.3.1 LED Open Detection
The LED Open Detection (LOD) function detects faults caused by an open circuit in any LED, or a short from
OUTn to VLED with low impedance. This function was realized by comparing the OUTn voltage to the LOD
detection threshold voltage level set by LODVTH_R/LODVTH_G/LODVTH_B (See FC3 for more details). If the
OUTn voltage is higher than the programmed voltage, the corresponding output LOD bit is set to 1 to indicate
an open LED. Otherwise, the output of that LOD bit is 0. LOD data output by the detection circuit are valid only
during the OUTn turning on period.
Figure 7-8 shows the equivalent circuit of LED open detection.
18
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
VG
VR
B0 G0 R0
LODVTH_R
…
B15 G15 R15
VB
LODVTH_G
VB
VG
VR
LODVTH_B
LODVTH_R
LODVTH_G
LODVTH_B
+
+
+
+
+
+
–
–
–
–
–
–
Channel
Control
Channel
Control
Channel
Control
Channel
Control
Channel
Control
Channel
Control
LOD Detection
0b - Normal
1b - LED-open
48-bit LOD Data
SCLK
SIN
48-bit
LSB
READLOD
48-bit Common Shift Register
MSB
SOUT
Figure 7-8. LED Open Detection Circuit
The LED open detection function records the position of the open LED, which contains the scan line number and
relevant channel number. The scan line order is stored LOD_LINE_WARN register (see FC16, FC17 for more
details), and the channel number is latched into the internal 48-bit LOD data register (see FC20 for more details)
at the end of each segment. Figure 7-9 shows the bit arrangement of the LOD data register.
Figure 7-9. Bit Arrangement in LOD Data Register
7.3.5.3.2 Read LED Open Information
The LOD readback function must be enabled before read LED open information. This function is enabled by
LOD_LSD_RB (see FC3 for more details).
Figure 7-10 shows the steps to read LED open information. Wait at least one sub-period time between Step2
and Step3 command.
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
19
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
Figure 7-10. Steps to Read LED Open Information
7.3.5.3.3 LED Open Caterpillar Removal
Figure 7-11 shows the caterpillar issue caused by open LED. Suppose the LED0-1 is an open LED. When line 0
is chosen and the OUT1 is turned on, the OUT1 voltage is forced to approach to VLED because of the broken
path of the current source. However, the voltage of the un-chosen lines are below the Vclamp which is much
lower than VLED, causing all LEDs which connect to the channel OUT1, light unwanted.
20
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
Figure 7-11. LED Open Caterpillar
The LP5891 implements circuits that can eliminate the caterpillar issue caused by open LEDs. The LED open
caterpillar removal function is configured by LOD_RM_EN (see FC0 for more details). When LOD_RM_EN is set
to 1b, the caterpillar removal function is enabled. The corresponding channel OUTn is turned off when scanning
to line with open LED, The caterpillar issue is eliminated until device resets or LOD_RM_EN is set to 0b.
The internal caterpillar elimination circuit can handle a maximum of three lines that have open LEDs fault
condition. If there are open LEDs located in three or fewer lines, the LP5891 is able to handle the open LEDs all
in these lines. If there are open LEDs in more than three lines, the caterpillar issue is solved for the lines where
the first three open LEDs were detected, but the open LEDs in the fourth and subsequent lines still cause the
caterpillar issue.
7.3.5.4 LED Short and Weak Short Circuitry Detection and Removal
7.3.5.4.1 LED Short/Weak Short Detection
The LED short detection (LSD) function detects faults caused by a short circuit in any LED. This function was
realized by comparing the OUTn voltage to the LSD threshold voltage. If the OUTn voltage is lower than the
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
21
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
threshold voltage, the corresponding output LSD bit is set to 1 to indicate an short LED, otherwise, the output of
that LSD bit is 0. LSD data output by the detection circuit are valid only during the OUTn turning on period.
LSD weak short can be detected by adjusting threshold voltage, which level is set by LSDVTH_R/LSDVTH_G/
LSDVTH_B (See FC3 for more details).
Figure 7-12 shows the equivalent circuit of LED short detection.
VG
VR
B0 G0 R0
LSDVTH_R
…
B15 G15 R15
VB
LSDVTH_G
VB
VG
VR
LSDVTH_B
LSDVTH_R
LSDVTH_G
LSDVTH_B
+
+
+
+
+
+
–
–
–
–
–
–
Channel
Control
Channel
Control
Channel
Control
Channel
Control
Channel
Control
Channel
Control
LSD Detection
0b - Normal
1b - LED-short
48-bit LSD Data
SCLK
SIN
48-bit
LSB
READLSD
MSB
SOUT
48-bit Common Shift Register
Figure 7-12. LED Short Detection Circuit
The LED short detection function records the position of the short LED, which contains the scan line order and
relevant channel number. The scan line order is stored LSD_LINE_WARN register (see FC18, FC19 for more
details), and the channel number is latched into the internal 48-bit LSD data register (see FC21 for more details)
at the end of each segment. Figure 7-13 shows the bit arrangement of the LSD data register.
Figure 7-13. Bit Arrangement in the LSD Data Register
7.3.5.4.2 Read LED Short Information
The LSD readback function must be enabled before reading LED Short information. This function is enabled by
LOD_LSD_RB (see FC3 for more details).
22
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
Figure 7-14 shows the steps to read LED Short information. Wait at least one sub-period time between Step2
and Step3 command.
Figure 7-14. Steps to Read LED Short Information
7.3.5.4.3 LSD Caterpillar Removal
Figure 7-15 shows the LSD caterpillar issue caused by short LED. Suppose the LED0-1 is a short LED. When it
scans to the line1 and the OUT1 is turned off, the OUT1 voltage is the same with scan line0 voltage because of
the short path of the LED0-1. At this time, there is a current path from the line0 to the GND through the LED1-1
and SW1-1, which causes LED1-1 light unwanted.
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
23
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
Figure 7-15. LED Short Caterpillar
The LP5891 device implements internal circuits that can eliminate the caterpillar issue by short LEDs. As is
shown in Figure 7-15, the LED short caterpillar is caused by the voltage of the Vclamp on the line. So it can be
solved by adjusting the LSD_RM_EN (see FC3 for more details) to let the voltage drop of the LED1-1 be smaller
than LED forward voltage.
24
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
7.4 Device Functional Modes
The device functional modes are shown in Figure 7-16.
Figure 7-16. Functional Modes
•
•
•
•
•
Initialization: The device enters into Initialization when Vcc goes down to UVLO voltage. In this mode, all the
registers are reset. Entry can also be from any state.
Normal: The device enters the normal mode when Vcc is higher than UVLO threshold. The display process
is shown as below in normal mode.
Power saving: The device automatically enters and gets out from the power save mode when it detects the
condition PSin and PSout. In this mode, all channels turn off. PSin: after the device detects that the display
data of the next frame all equal to zero, it enters in to power save mode when the VSYNC comes. PSout:
after the device detects that there is non-zero display data of the next frame, it gets out from power save
mode immediately.
IREF resistor short protection: The device automatically enters and gets out from the IREF resistor short
protection mode when it detects the condition ISPin and ISPout. In this mode, all channels turn off. ISPin:
the device detects that the reference voltage is smaller than 0.195 V ISPout: the device detects that the
reference voltage is larger than 0.325 V.
Thermal shutdown: The device automatically enters and gets out from the thermal shutdown mode when it
detects the condition TSDin and TSDout. In this mode, all channels turn off. TSDin: the device detects that
the junction temperature exceeds 170°C TSDout: the device detects that the junction temperature is below
155°C.
7.5 Continuous Clock Series Interface
The continuous clock series interface (CCSI) provides access to the programmable functions and registers,
SRAM data of the device. The interface contains two input digital pins, they are the serial data input (SIN) and
serial clock (SCLK). Moreover, there is an another wire called serial data output (SOUT) as the output digital
signal of the device. The SIN is set to HIGH when device is in idle status and the SCLK must be existent and
continuous all the time considering as the clock source of internal Frequency Multiplier, the SOUT is used to
transmit the data or read the data of internal registers.
This protocol can support up to 32 devices cascaded in a data chain. The devices receive the chip index
command after power up. The chip index command configured addresses of the devices from 0x00 up to 0x1F
according to the sequence that receives the command. Then the controller can communicate with all the devices
through the broadcast way or particular device through non-broadcast way.
The broadcast is mainly used to transmit function control commands. All the devices in a data chain receive
the same data in this way. The non-broadcast is mainly used to transmit function control commands or display
data, and each device receives its own data in this way. These two ways are distinguished by the command
identification.
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
25
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
7.5.1 Data Validity
The data on DIN wire must be stable at rising edges of the SCLK in transmission.
7.5.2 CCSI Frame Format
Figure 7-17 defines the format of the command and data transmission. There are four states in one frame.
• IDLE: SCLK is always existent and continuous, and DIN is always HIGH.
• START: DIN changes from HIGH to LOW after the IDLE states.
• DATA:
– Head_bytes: It is the command identifier, contains one 16-bit data and one check bit. It can be WRITE
COMMAND ID or READ COMMAND ID (see Register Maps for more details).
– Data_bytes_N: The Nth data-bytes, contains 3 × 17-bit data, each 17-bit data contains one 16-bit data
and one check bit. N is the number of devices cascaded in a data chain.
• END: The device recognizes continuous 18-bit HIGH on DIN, then returns to IDLE state.
• CHECK BIT: The check bit (17th bit) value is the NOT of 16th bit value to avoid continuous 18-bit HIGH (to
distinguish with END).
Figure 7-17. CCSI Frame
The IDLE state is not necessary, which means the START state of the next frame can connect to the END state
of the current frame.
7.5.3 Write Command
Take m devices cascaded in a data chain for example.
7.5.3.1 Chip Index Write Command
The chip index is used to set the identification of the device cascaded in a data chain. When the first device
receives the chip index command Head_bytes1, it sets the current address to 00h and meanwhile change the
chip index command Head_bytes2, then sends to the next device. When the device receives the Head_bytes2, it
sets the address to 01h and meanwhile changes the chip index command Head_bytes3, then sends to the next
device, likewise, all the cascaded devices get their unique identifications.
SOUT
Controller SCLK
SIN
Device_1
ST
Device_...
Head_bytes1
Device_m
END
ST
Head_bytes...
END
ST
Head_bytesm
END
Figure 7-18. Chip Index Write Command
26
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
7.5.3.2 VSYNC Write Command
The VSYNC is used to sync the display of each frame for the devices in a cascaded chain. this command is a
write-only command. The devices receive VSYNC command one time from the controller in each frame, and the
VSYNC command needs to be active for all devices at the same time.
Because some devices receive the command earlier in the data chain, they need to wait until the last device
receives the command, then all the devices are active at that time. To realize such function, each device needs
to know its delay time from receiving VSYNC command to enabling VSYNC. The device uses some register bits
to restore the device number in a data chain. This number minuses the device identification, and the result is the
delay time of the device.
Because the sync function has been done by the device, the controller only must send the VSYNC command to
the first device in a data chain.
SOUT
Controller SCLK
SIN
Device_1
ST
Device_...
Head_bytes
Device_m
END
ST
Head_bytes
END
ST
END
Head_bytes
ST
Head_bytes
END
Figure 7-19. VSYNC Write Command
7.5.3.3 MPSM Write Command
The MPSM command is used to control the intelligent power save mode of devices in the same matrix. The
device detects all zero data in a stackable module and receives MPSM command in current frame, then when
VSYNC command comes, all devices in the same matrix turn off. After the device detects that there is non-zero
display data of the next frame, it gets out from intelligent power save mode until MSPM command comes in
current frame.
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
27
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
Figure 7-20. Design Procedure for MPSM Command
7.5.3.4 Standby Clear and Enable Command
Standby clear command and standby enable command are used to control intelligent power save mode of
devices in the same daisy chain. When the device receives standby enable command, it enters to intelligent
power save mode right away and does not have to wait for other devices in a module or daisy chain. After the
device receives standby enable command, it exits from intelligent power save mode immediately and does not
wait for other devices in a module or daisy chain.
7.5.3.5 Soft_Reset Command
The Soft_Reset Command is used to reset all the function registers to the default value, except for SRAM data.
The format of this command is the same with VSYNC shown as VSYNC Write Command. The difference is the
headbytes.
28
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
7.5.3.6 Data Write Command
The device can receive the function control with broadcast and non-broadcast way, which depends on the
configuration of the devices. If the cascaded devices have the same configuration, broadcast is used,. If the
cascaded devices have the different configurations, non-broadcast is used. It is always the MSB transmitted first
and the LSB transmitted last. For 48-bits RGB data, the Blue data must be transmitted first, then the Green, and
last the Red data.
For broadcast, the devices receive the same data, when devices recognize the broadcast command, they copy
the data to their internal registers. Generally, it is used for write FC0-FC13 command, LOD/LSD.
Figure 7-21. Data Write Command with Broadcast
Figure 7-22 shows the time diagram of the Data Write Command with Broadcast.
Figure 7-22. Data Write Command with Broadcast (Timing Diagram)
For non-broadcast, the devices receive the different data, the controller prepares the data as the figure shows.
One pixel data is written to the corresponding device in each command. When the first device receives the END,
it cuts off the last 51-bit (3 × 17-bit) data before the END, and the left are shifted out from SDO to the second
device. Similarly, when the second device receives the END bytes from the former device, it cuts off the last
51-bit (3 × 17-bit) data before the END, and the left are shifted out to the next device. Generally, it is used for
write SRAM command (WRTGS). Details for how to write a frame data into memory bank can be found in Write
a Frame Data into Memory Book.
Figure 7-23. Data Write Command with Non-Broadcast
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
29
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
Figure 7-24 shows the time diagram of the Data Write Command with Non-Broadcast.
Figure 7-24. Data Write Command with Non-Broadcast (Timing Diagram)
7.5.4 Read Command
The controller sends the read command. When the first device receives this command, it inserts its 48-bit
data before End_bytes, and meanwhile shifts out to the second device. When the second device receives this
command, it inserts its 48-bit data before End_bytes and meanwhile shifts out to the third device. The data of all
the device are shifted out from the last device SOUT with this flow. The MSB is always transmitted first and the
LSB transmitted last.
Figure 7-25. Data Read Command
30
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
7.6 PWM Grayscale Control
7.6.1 Grayscale Data Storage and Display
7.6.1.1 Memory Structure Overview
The LP5891 implements a display memory unit to achieve high refresh rate and high contrast ratio in an LED
display products. The internal display memory unit is divided into two BANKs: BANK A and BANK B. During the
normal operation, one BANK is selected to display the data of current frame, another is used to restore the data
of next frame. The BANK switcher is controlled by the BANK_SEL bit, which is an internal flag register bit.
After power on, BANK_SEL is initialized to 0, and BANK A is selected to restore the data of next frame.
Meanwhile, the data in BANK B is read out for display. When one frame has elapsed, the controller sends the
vertical synchronization (VSYNC) command to start the next frame, the BANK_SEL bit value is toggled and the
selection of the two BANKs reverses. Repeat this operation until all the frame images are displayed.
With this method, the LP5891 device can display the current frame image at a very high refresh rate. See Figure
7-26 for more details about the BANK-selection exchange operation.
Figure 7-26. Bank Selection Exchange Operation
7.6.1.2 Details of Memory Bank
Each memory BANK contains the frame-image grayscale data of all the 64 lines. Each line comprises sixteen
48-bit-width memory units. Each memory unit contains the grayscale data of the corresponding R/G/B channels.
Depending on the number of scan lines set in SCAN_NUM (FC0 bit 21 to bit 16), the total number of memory
units that must be written in one BANK is: 48 × the number of scan lines. For example, if the number of scan
lines is set to 64, then 3072 (64 × 48 = 3072) memory units must be written during each frame period.
Figure 7-27 shows the detailed memory structure of the LP5891 device.
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
31
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
Figure 7-27. LP5891 Memory-unit Structure
7.6.1.3 Write a Frame Data into Memory Bank
After power on, the LP5891 internal flag BANK_SEL, and counters LINE_COUNT, CHANNEL_COUNT, are all
initialized to 0. Thus, the memory unit of channel R0/G0/B0, locating in line 0 of BANK A, is selected to restore
the data transimitted the first time after VSYNC command.
When the first WRTGS command is received, all the data in the common shift register is latched into the
memory unit of channel R0/G0/B0, locating in line 0 of BANK A. Then CHANNEL_COUNT increases by 1 and
LINE_COUNT stays the same. Thus, the memory unit of channel R1/G1/B1, locating in line 0 of BANK A, is
selected to restore the data transimitted the second time after VSYNC command.
When the second WRTGS command is received, all the data in the common shift register is latched into the
memory unit of channel R1/G1/B1, locating in line 0 of BANK A. Then CHANNEL_COUNT increases by 1 and
LINE_COUNT stays the same. Thus, the memory unit of channel R2/G2/B2, locating in line 0 of BANK A, is
selected to restore the data transimitted the third time after VSYNC command.
Repeat the grayscale-data-write operation until the 16th WRTGS command is received. Then
CHANNEL_COUNT is reset to 0 and LINE_COUNT increases by 1. Thus, the memory unit of channel
R0/G0/B0, locating in line 1 of BANK A, is selected to restore the data transimitted the 17th time after VSYNC
command.
32
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
Repeat this operation for each line until the LINE_COUNT exceeds the number of scan lines set in the
SCAN_NUM (See FC0 register bit21-16 ) and all scan lines have been updated with new GS data, which means
one frame of GS data is restored into the memory BANK. Then the LINE_COUNT is reset to 0.
7.6.2 PWM Control for Display
To increase the refresh rate in time-multiplexing display system, a DS-PWM (Dynamic Spectrum-Pulse Width
Modulation) algorithm is proposed in this device. One frame is divided into many segments shown below.
Note that one frame is divided into n sub-periods, n is set by SUBP_NUM (FC0 register bit24-22), and each
sub-period is divided into 32 segments for 32 scan lines. Each segment contains GS GCLKs time for grayscale
data display and T_SW GCLKs time for switching lines. GS is configured by the SEG_LENGTH (FC1 register
bit9-0 in Table 7-8) , and T_SW is the line switch time, which is configured by the LINE_SWT (see FC1 register
bit 40-37 in Table 7-8).
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
33
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
Figure 7-28. DS-PWM Algorithm with 32 Scan Lines
The DS-PWM can not only increase the refresh rate meanwhile keep the same frame rate, but also decrease the
brightness loss in low grayscale, which can smoothly increase the sub-period number when the grayscale data
increases.
To achieve ultra-low luminance, the LED driver must have the ability to output a very short current pulse (1
GCLK time), however, because of the parasitic capacitor of the LEDs, such pulse can not turn on the LEDs. The
larger GCLK frequency is, the harder to turn on LEDs.
DS-PWM algorithm have a parameter called subperiod threshold, which is used to calculate when to change
subperiod number according to the giving grayscale data. Subperiod threshold defines the LED minimum turn-on
time, so as to conquer the current loss caused by LED parasitic capacitor. Subperiod threshold is configured by
the LG_STEP_R/G/B (FC1 register bit24-10 in Table 7-8).
With DS-PWM algorithm, the brightness has smoothly increased with the gradient grayscale data.
7.7 Register Maps
Table 7-5. Register Maps
34
REGISTER NAME
TYPE
WRITE COMMAND
ID
READ COMMAND
ID
DESCRIPTION
FC0
R/ W
AA00h
AA60h
Common configuration
FC1
R/ W
AA01h
AA61h
Common configuration
FC2
R/ W
AA02h
AA62h
Common configuration
FC3
R/ W
AA03h
AA63h
Common configuration
FC4
R/ W
AA04h
AA64h
Common configuration
FC14
R/ W
AA0Eh
AA6Eh
Locate the line for LOD
FC15
R/ W
AA0Fh
AA6Fh
Locate the line for LSD
FC16
R
AAA0h
Read the lines' warning of LOD from 64th ~ 49th
line
FC17
R
AAA1h
Read the lines' warning of LOD from 48th~1st line
FC18
R
AAA2h
Read the lines' warning of LSD from 64th ~ 49th
line
FC19
R
AAA3h
Read the lines' warning of LSD from 48th~1st line
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
Table 7-5. Register Maps (continued)
WRITE COMMAND
ID
READ COMMAND
ID
DESCRIPTION
R
AAA4h
Read the channel's warning of LOD
R
AAA5h
Read the channel's warning of LSD
REGISTER NAME
TYPE
FC20
FC21
Chip Index
R/ W
AA10h
VSYNC
W
AAF0h
AA70h
Read/Write chip index
Write VSYNC command
MPSM
W
AA90h
Write matrix PSM command
SBY_CLR
W
AAB0h
Write standby clear command
SBY_EN
W
AAB1h
Write standby enable command
Soft_Reset
W
AA80h
Reset the all the registers expect the SRAM
SRAM
W
AA30h
Write or read the SRAM data
Table 7-6. Access Type Codes
Access Type
Code
Description
R
Read
W
Write
Read Type
R
Write Type
W
Reset or Default Value
-n
Value after reset or the default
value
7.7.1 FC0
FC0 is shown in FC0 Register and described in FC0 Register Field Descriptions.
Figure 7-29. FC0 Register
47
46
45
44
43
42
41
40
39
38
37
36
35
34
LSD_R
M_EN
RESERVED
GRP_DLY_B
GRP_DLY_G
GRP_DLY_R
RESERVED
R/
W-0b
R-01b
R/W-000b
R/W-000b
R/W-000b
R-000b
31
30
29
28
27
26
25
24
23
22
21
20
19
18
FREQ_MUL
FREQ_
MOD
RESERVED
SUBP_NUM
SCAN_NUM
R/W-0111b
R/
W-0b
R-000b
R/W-000b
R/W-000000b
15
14
13
12
11
10
9
8
7
6
5
4
3
2
LODR
M_EN
PSP_MOD
PS_EN
RESERVED
PDC_E
N
RESERVED
CHIP_NUM
R/
W-0b
R/W-00b
R/
W-0b
R-000b
R/
W-1b
R-000b
R/W-00111b
33
32
17
16
1
0
Table 7-7. FC0 Register Field Descriptions
Bit
Field
Type
Reset
Description
4-0
CHIP_NUM
R/W
00111b
Set the device number
00000b: 1 device
...
01111b: 16 devices
...
11111b: 32 devices
7-5
RESERVED
R
000b
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
35
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
Table 7-7. FC0 Register Field Descriptions (continued)
Bit
Field
Type
Reset
Description
PDC_EN
R/W
1b
Enable or disable pre-discharge function
0b: disable
1b: enable
RESERVED
R
000b
PS_EN
R/W
0b
Enable or disable the power saving mode
0b: disable
1b: enable
PSP_MOD
R/W
00b
Set the powering saving plus mode
00b: disable
01b: save power at high level
10b: save power at middle level
11b: save power at low level
15
LODRM_EN
R/W
0b
Enable or disable the LED open load removal function
0b: disable
1b: enable
21-16
SCAN_NUM
R/W
000000b
Set the scan line number
000000b: 1 line
...
001111b: 16 lines
...
011111b: 32 lines
...
111111b: 64 lines
24-22
SUBP_NUM
R/W
000b
Set the subperiod number
000b: 16
001b: 32
010b: 48
011b: 64
100b: 80
101b: 96
110b: 112
111b: 128
27-25
RESERVED
R
000b
28
FREQ_MOD
R/W
0b
Set the GCLK multiplier mode
0b: low frequency mode, 40MHz to 80MHz
1b: high frequency mode, 80MHz to 160MHz
32-29
FREQ_MUL
R/W
0111b
Set the GCLK multiplier frequency
0000b: 1 x SCLK frequency
...
0111b: 8 x SCLK frequency
...
1111b: 16 x SCLK frequency
35-33
RESERVED
R
000b
38-36
GRP_DLY_R
R/W
000b
8
11-9
12
14-13
36
Set the Red group delay, forward PWM mode only
000b: no delay
001b: 1 GCLK
010b: 2 GCLK
011b: 3 GCLK
100b: 4 GCLK
101b: 5 GCLK
110b: 6 GCLK
111b: 7 GCLK
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
Table 7-7. FC0 Register Field Descriptions (continued)
Bit
Field
Type
Reset
Description
41-39
GRP_DLY_G
R/W
000b
Set the Green group delay, forward PWM mode only
000b: no delay
001b: 1 GCLK
010b: 2 GCLK
011b: 3 GCLK
100b: 4 GCLK
101b: 5 GCLK
110b: 6 GCLK
111b: 7 GCLK
44-42
GRP_DLY_B
R/W
000b
Set the Blue group delay, forward PWM mode only
000b: no delay
001b: 1 GCLK
010b: 2 GCLK
011b: 3 GCLK
100b: 4 GCLK
101b: 5 GCLK
110b: 6 GCLK
111b: 7 GCLK
46-45
RESERVED
R
01b
47
LSD_RM_EN
R/W
0b
Enable or disable short LED caterpillar
0b: disable
1b: enable
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
37
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
7.7.2 FC1
FC1 is shown in FC1 Register and described in FC1 Register Field Descriptions.
Figure 7-30. FC1 Register
47
46
45
44
RESE
RVED
43
42
41
40
BLK_ADJ
R-0b
30
29
28
27
38
37
36
LINE_SWT
R/W-000000b
31
39
R/W-0111b
26
25
24
23
35
34
33
LG_ENH_B
R/W-0000b
22
21
20
19
18
17
LG_ENH_G
LG_ENH_R
LG_STEP_B
LG_STEP_G
R/W-0000b
R/W-0000b
R/W-01001b
R/W-01001b
15
14
LG_ST
EP_G
13
12
11
10
9
8
7
32
LG_EN
H_G
6
5
4
LG_STEP_R
SEG_LENGTH
R/W-01001b
R/W-0'000'000'000b
3
2
1
16
0
Table 7-8. FC1 Register Field Descriptions
38
Bit
Field
Type
Reset
Description
9-0
SEG_LENGTH
R/W
0'000'000'0 Set the GCLK number in each segment
00b
127d: 128 GCLK
...
1023d: 1024 GCLK
others: 128 GCLK
14-10
LG_STEP_R
R/W
01001b
Adjust the smooth of the brightness in low grayscale
00000b: level 1
...
01111b: level 16
...
11111b: level 32
19-15
LG_STEP_G
R/W
01001b
Adjust the smooth of the brightness in low grayscale
00000b: level 1
...
01111b: level 16
...
11111b: level 32
24-20
LG_STEP_B
R/W
01001b
Adjust the smooth of the brightness in low grayscale
00000b: level 1
...
01111b: level 16
...
11111b: level 32
28-25
LG_ENH_R
R/W
0000b
Adjust low grayscale enhancement of red channels
0000b: level 0
...
0111b: level 7
...
1111b: level 15
32-29
LG_ENH_G
R/W
0000b
Adjust low grayscale enhancement of green channels
0000b: level 0
...
0111b: level 7
...
1111b: level 15
36-33
LG_ENH_B
R/W
0000b
Adjust low grayscale enhancement of blue channels
0000b: level 0
...
0111b: level 7
...
1111b: level 15
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
Table 7-8. FC1 Register Field Descriptions (continued)
Bit
Field
Type
Reset
Description
40-37
LINE_SWT
R/W
0111b
Set the scan line switch time.
0000b: 45 GCLK
0001b: 2x30 GCLK
...
0111b: 8x30 GCLK
...
1111b: 16x30 GCLK
46-41
BLK_ADJ
R/W
000000b
Set the black field adjustment
000000b: 0 GCLK
...
011111b: 31 GCLK
...
111111b: 63 GCLK
RESERVED
R
0b
Reserved bit.
47
7.7.3 FC2
FC2 is shown in FC2 Register and described in FC2 Register Field Descriptions.
Figure 7-31. FC2 Register
47
46
MPSM
_EN
RESE
RVED
MOD_SIZE
R/
W-0b
R-0b
R/W-111b
31
30
45
44
29
28
43
42
27
13
39
R/
W-0b
R/
W-1b
R/
W-1b
R/
W-1b
26
25
24
23
LG_COLOR_R
R/W-0000b
14
40
11
10
9
37
36
35
7
33
LG_COLOR_B
R-000b
R/W-0000b
22
21
20
19
6
5
18
17
32
16
DE_COUPLE1_G
R/W-0000b
8
34
RESERVED
DE_COUPLE1_B
R/W-0000b
12
38
SUBP_ CH_B_ CH_G_ CH_R_
MAX_2 IMMU IMMU IMMU
56
NITY
NITY
NITY
LG_COLOR_G
15
41
R/W-0000b
4
3
2
1
DE_COUPLE1_R
V_PDC_B
V_PDC_G
V_PDC_R
R/W-0000b
R/W-0110b
R/W-0110b
R/W-0110b
0
Table 7-9. FC2 Register Field Descriptions
Bit
Field
Type
Reset
Description
3-0
V_PDC_R
R/W
0110b
Set the Red pre_discharge voltage (typical), the voltage value
must not be higher than (VR-1.3V).
0000b: 0.1V
0001b: 0.2V
0010b: 0.3V
0011b: 0.4V
0100b: 0.5V
0101b: 0.6V
0110b: 0.7V
0111b: 0.8V
1000b: 0.9V
1001b: 1.0V
1010b: 1.1V
1011b: 1.3V
1100b: 1.5V
1101b: 1.7V
1110b: 1.9V
1111b: 2.1V
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
39
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
Table 7-9. FC2 Register Field Descriptions (continued)
40
Bit
Field
Type
Reset
Description
7-4
V_PDC_G
R/W
0110b
Set the Green pre_discharge voltage (typical), the voltage value
must not be higher than (VG-1.3V).
0000b: 0.1V
0001b: 0.2V
0010b: 0.3V
0011b: 0.4V
0100b: 0.5V
0101b: 0.6V
0110b: 0.7V
0111b: 0.8V
1000b: 0.9V
1001b: 1.0V
1010b: 1.1V
1011b: 1.3V
1100b: 1.5V
1101b: 1.7V
1110b: 1.9V
1111b: 2.1V
11-8
V_PDC_B
R/W
0110b
Set the Blue pre_discharge voltage (typical), the voltage value
must not be higher than (VB-1.3V).
0000b: 0.1V
0001b: 0.2V
0010b: 0.3V
0011b: 0.4V
0100b: 0.5V
0101b: 0.6V
0110b: 0.7V
0111b: 0.8V
1000b: 0.9V
1001b: 1.0V
1010b: 1.1V
1011b: 1.3V
1100b: 1.5V
1101b: 1.7V
1110b: 1.9V
1111b: 2.1V
15-12
DE_COUPLE1_R
R/W
0000b
Set the Red decoupling level
0000b: level 1 (lowest)
...
0111b: level 8 (middle)
...
1111b: level 16(highest)
19-16
DE_COUPLE1_G
R/W
0000b
Set the Green decoupling level
0000b: level 1 (lowest)
...
0111b: level 8 (middle)
...
1111b: level 16(highest)
23-20
DE_COUPLE1_B
R/W
0000b
Set the Blue decoupling level
0000b: level 1 (lowest)
...
0111b: level 8 (middle)
...
1111b: level 16(highest)
27-24
LG_COLOR_R
R/W
0000b
Set the Red brightness compensation level of the low grayscale
0000b: level 1 (lowest)
...
0111b: level 8 (middle)
...
1111b: level 16(highest)
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
Table 7-9. FC2 Register Field Descriptions (continued)
Bit
Field
Type
Reset
Description
31-28
LG_COLOR_G
R/W
0000b
Set the Red brightness compensation level of the low grayscale
0000b: level 1 (lowest)
...
0111b: level 8 (middle)
...
1111b: level 16(highest)
35-32
LG_COLOR_B
R/W
0000b
Set the Red brightness compensation level of the low grayscale
0000b: level 1 (lowest)
...
0111b: level 8 (middle)
...
1111b: level 16(highest)
38-36
RESERVED
R
000b
39
CH_R_IMMUNITY
R/W
1b
Set the immunity of the Red channels group
0b: high immunity
1b: low immunity
40
CH_G_IMMUNITY
R/W
1b
Set the immunity of the Green channels group
0b: high immunity
1b: low immunity
41
CH_B_IMMUNITY
R/W
1b
Set the immunity of the Blue channels group
0b: high immunity
1b: low immunity
42
SUBP_MAX_256
R/W
0b
Set the maximum subperiod to 256.
0b: disable
1b: enable
45-43
MOD_SIZE
R/W
111b
Set the module size.
000b: 16x16 RGB pixels
001b:32x32 RGB pixels
010b:48x48 RGB pixels with D3 reverse, and scan sequence
D1,D2,D3
011b:48x48 RGB pixels with D3 reverse, and scan sequence
D1,D3,D2
100b:48x64 RGB pixels with D3, D4 reverse, and scan
sequence D1,D2,D3
101b:48x64 RGB pixels with D3,D4 reverse, and scan sequence
D1,D3,D2
110b:64x64 RGB pixels with D3,D4 reserve, and scan seqeunce
D1,D2,D3,D4
111b:64x64 RGB pixels with D3,D4 reverse,and scan sequence
D1,D4,D2,D3
46
RESERVED
R
0b
47
MPSM_EN
R/W
0b
Enable or disable matrix power saving mode.
0b: disable
1b: enable
7.7.4 FC3
FC3 is shown in FC3 Register and described in FC3 Register Field Descriptions.
Figure 7-32. FC3 Register
47
46
45
44
LSDVTH_B
15
30
14
42
41
LSDVTH_G
R/W-000b
31
43
R/W-000b
29
13
28
27
40
39
38
LSDVTH_R
25
24
36
35
R/W-0111b
23
22
21
19
CC_G
R/W-0111 1111b
10
9
8
7
6
5
4
32
R/W-011b
20
CC_B
11
33
BC
R/W-0111 1111b
12
34
LSD_RM
R/W-000b
26
37
3
18
17
16
2
1
0
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
41
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
Figure 7-32. FC3 Register (continued)
CC_R
LOD_L RESE
SD_RB RVED
R/W-0111 1111b
R/
W-0b
R-0b
LODVTH_B
LODVTH_G
LODVTH_R
R/W-00b
R/W-00b
R/W-00b
Table 7-10. FC3 Register Field Descriptions
42
Bit
Field
Type
Reset
Description
1-0
LODVTH_R
R/W
00b
Set the Red LED open load detection threshold
00b: (VLEDR-0.2) V
01b: (VLEDR-0.5) V
10b: (VLEDR-0.9) V
11b: (VLEDR-1.2) V
3-2
LODVTH_G
R/W
00b
Set the Green LED open load detection threshold
00b: (VLEDG-0.2) V
01b: (VLEDG-0.5) V
10b: (VLEDG-0.9) V
11b: (VLEDG-1.2) V
5-4
LODVTH_B
R/W
00b
Set the Blue LED open load detection threshold
00b: (VLEDB-0.2) V
01b: (VLEDB-0.5) V
10b: (VLEDB-0.9) V
11b: (VLEDB-1.2) V
6
RESERVED
R
0b
7
LOD_LSD_RB
R/W
0b
15-8
CC_R
R/W
0111 1111b Set the Red color brightness level
0000 0000b: level 0 (lowest)
...
0111 1111b: level 127 (middle)
...
1111 1111b: level 255 (highest)
23-16
CC_G
R/W
0111 1111b Set the Green color brightness level
0000 0000b: level 0 (lowest)
...
0111 1111b: level 127 (middle)
...
1111 1111b: level 255 (highest)
31-24
CC_B
R/W
0111 1111b Set the Blue color brightness level
0000 0000b: level 0 (lowest)
...
0111 1111b: level 127 (middle)
...
1111 1111b: level 255 (highest)
34-32
BC
R/W
011b
Enable or disable the LOD and LSD readback function
0b: disabled
01b: enabled
Set the global brightness level
000b: level 0 (lowest)
...
011b: level 3 (middle)
...
111b: level 7 (highest)
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
Table 7-10. FC3 Register Field Descriptions (continued)
Bit
Field
Type
Reset
Description
38-35
LSD_RM
R/W
0111b
Set the LED short removal level
0000b: level 1
0001b: level 2
0010b: level 3
0011b: level 4
0100b: level 5
0101b: level 6
0110b: level 7
0111b: level 8
1000b: level 9
1001b: level 10
1010b: level 11
1011b: level 12
1100b: level 13
1101b: level 14
1110b: level 15
1111b: level 16
41-39
LSDVTH_R
R/W
000b
Set the Red LED short/weak short circuitry detection threshold
(typical)
000b: 0.2 V
001b: 0.4 V
010b: 0.8 V
011b: 1.0 V
100b: 1.2 V
101b: 1.4 V
110b: 1.6 V
111b: 1.8 V
44-42
LSDVTH_G
R/W
000b
Set the Green LED short/weak short circuitry detection threshold
(typical)
000b: 0.2 V
001b: 0.4 V
010b: 0.8 V
011b: 1.2 V
100b: 1.6 V
101b: 2 V
110b: 2.4 V
111b: 2.8 V
47-45
LSDVTH_B
R/W
000b
Set the Blue LED short/weak short circuitry detection threshold
(typical)
000b: 0.2 V
001b: 0.4 V
010b: 0.8 V
011b: 1.2 V
100b: 1.6 V
101b: 2 V
110b: 2.4 V
111b: 2.8 V
7.7.5 FC4
FC4 is shown in FC4 Register and described in FC4 Register Field Descriptions.
Figure 7-33. FC4 Register
47
46
45
RESERVED
30
43
28
26
SR_ON_B
12
11
39
24
SR_ON_G
9
8
37
36
35
FIRST_LINE_DIM
33
32
CAURSE
_G
CAURSE
_R
R/W-0b
R/W-0b
R/W-0b
20
19
18
17
16
SR_ON_R
SR_OFF
_B
SR_OFF
_G
SR_OFF
_R
FINE_B
FINE_G
FINE_R
R/W-01b
R/W-0b
R/W-0b
R/W-0b
R/W-0b
R/W-0b
R/W-0b
5
4
3
2
1
0
7
R/W-0000b
34
CAURSE
_B
21
23
R/W-01b
10
38
DE_COU
PLE2
R/W-0b
25
R/W-01b
13
40
R/W-1000b
27
R-0000b
14
41
DE_COUPLE3
R/W-0b
29
RESERVED
15
42
DE_COU
PLE3_EN
R-000b
31
44
22
6
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
43
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
Figure 7-33. FC4 Register (continued)
RESERV
ED
SCAN_R
EV
RESERVED
IMAX
RESERV
ED
R-0b
R/W-1b
R-0000 0000 1111b
R/W-0b
R-0b
Table 7-11. FC4 Register Field Descriptions
Bit
44
Field
Type
Reset
0
RESERVED
R
0b
Description
1
IMAX
R/W
0b
13-2
RESERVED
R
0000 0000
1111b
14
SCAN_REV
R/W
1b
15
RESERVED
R
0b
16
FINE_R
R/W
0b
Enable the Red brightness compensation level fine range
0b: disable
1b: enable
17
FINE_G
R/W
0b
Enable the Green brightness compensation level fine range
0b: disable
1b: enable
18
FINE_B
R/W
0b
Enable the Blue brightness compensation level fine range
0b: disable
1b: enable
19
SR_OFF_R
R/W
0b
Slew rate control function when Red turns off operation
0b: slow slew rate.
1b: fast slew rate.
20
SR_OFF_G
R/W
0b
Slew rate control function when Green turns off operation
0b: slow slew rate.
1b: fast slew rate.
21
SR_OFF_B
R/W
0b
Slew rate control function when Blue turns off operation
0b: slow slew rate.
1b: fast slew rate.
23-22
SR_ON_R
R/W
01b
Slew rate control function when Red turns on operation
00b: the slower slew rate.
01b: slow slew rate.
10b: fast slew rate.
11b: the faster slew rate.
25-24
SR_ON_G
R/W
01b
Slew rate control function when Green turns on operation
00b: the slower slew rate.
01b: slow slew rate.
10b: fast slew rate.
11b: the faster slew rate.
27-26
SR_ON_B
R/W
01b
Slew rate control function when Blue turns on operation
00b: the slower slew rate.
01b: slow slew rate.
10b: fast slew rate.
11b: the faster slew rate.
31-28
RESERVED
R
0000b
32
CAURSE_R
R/W
0b
Enable the Red brightness compensation level caurse range
0b: disable
1b: enable
33
CAURSE_G
R/W
0b
Enable the Green brightness compensation level caurse range
0b: disable
1b: enable
Set the maximum current of each channel
0b: 10mA maximum
01b: 20 mA maximum
When 2 device stackable, the scan lines PCB layout is reversed.
For the proper scan and SRAM read sequence, SCAN_REV
register is provided.
0b: the PCB layout sequence is L0-L15, L16-L31.
1b: the PCB layout sequence is L0-L15, L31-L16.
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
Table 7-11. FC4 Register Field Descriptions (continued)
Bit
Field
Type
Reset
Description
34
CAURSE_B
R/W
0b
Enable the Blue brightness compensation level caurse range
0b: disable
1b: enable
FIRST_LINE_DIM
R/W
0000b
Adjust the first line dim level
0000b: level 1
...
0111b: level 8
...
1111b: level 16
39
DE_COUPLE2
R/W
0b
Decoupling between ON and OFF channels
0b: disabled
1b: enabled
43-40
DE_COUPLE3
R/W
1000b
Set decoupling enhancement level
0000b: level 1
...
0111b: level 8
...
1111b: level 16
DE_COUPLE3_EN
R/W
0b
Enable decoupling enhancement
0b: disabled
1b: enabled
RESERVED
R
000b
38-35
44
47-45
7.7.6 FC14
FC14 is shown in FC14 Register and described in FC14 Register Field Descriptions.
Figure 7-34. FC14 Register
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
22
21
20
19
18
17
16
6
5
4
3
2
1
0
33
32
RESERVED
R-0b
31
30
29
28
27
26
25
24
23
RESERVED
R-0b
15
14
13
12
11
10
9
8
7
RESERVED
LOD_LINE_CMD
R-0b
R/W-000000b
Table 7-12. FC14 Register Field Descriptions
Bit
Field
Type
Reset
Description
5-0
LOD_LINE_CMD
R/W
000000b
Locate the line with LED open load warnings:
000000b: Line 0
...
011111b: Line 31
...
111111b: Line 63
47-6
RESERVED
R
0b
Reserved bits
7.7.7 FC15
FC15 is shown in FC15 Register and described in FC15 Register Field Descriptions.
Figure 7-35. FC15 Register
47
46
45
44
43
42
41
40
39
38
37
36
35
34
RESERVED
R-0b
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
45
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
Figure 7-35. FC15 Register (continued)
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
6
5
4
3
2
1
0
RESERVED
R-0b
15
14
13
12
11
10
9
8
7
RESERVED
LSD_LINE_CMD
R-0b
R/W-000000b
Table 7-13. FC15 Register Field Descriptions
Bit
Field
Type
Reset
Description
5-0
LSD_LINE_CMD
R/W
000000b
Locate the line with LED short circuitry warnings:
000000b: Line 0
...
011111b: Line 31
...
111111b: Line 63
47-6
RESERVED
R
0b
Reserved bits
7.7.8 FC16
FC16 is shown in FC16 Register and described in FC16 Register Field Descriptions.
Figure 7-36. FC16 Register
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
22
21
20
19
18
17
16
6
5
4
3
2
1
0
RESERVED
R-0b
31
30
29
28
27
26
25
24
23
RESERVED
R-0b
15
14
13
12
11
10
9
8
7
LOD_LINE_WARN[63:48]
R-0b
Table 7-14. FC16 Register Field Descriptions
Bit
Field
Type
Reset
Description
15-0
LOD_LINE_WARN[63:48]
R
0b
Read the line with LED open load warnings:
Bit 0 = 0, Line 48 has no warning; Bit 0 = 1, Line 48 has warning
...
Bit 15 = 0, Line 63 has no warning; Bit 15 = 1, Line 63 has
warning
47-16
RESERVED
R
0b
Reserved bits
7.7.9 FC17
FC17 is shown in FC17 Register and described in FC17 Register Field Descriptions.
Figure 7-37. FC17 Register
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
21
20
19
18
17
16
5
4
3
2
1
0
LOD_LINE_WARN[47:0]
R-0b
31
30
29
28
27
26
25
24
23
22
LOD_LINE_WARN[47:0]
R-0b
15
14
13
12
11
10
9
8
7
6
LOD_LINE_WARN[47:0]
46
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
Figure 7-37. FC17 Register (continued)
R-0b
Table 7-15. FC17 Register Field Descriptions
Bit
47-0
Field
Type
Reset
Description
LOD_LINE_WARN[47:0]
R
0b
Read the line with LED open load warnings:
Bit 0 = 0, Line 0 has no warning; Bit 0 = 1, Line 0 has warning
...
Bit 47 = 0, Line 47 has no warning; Bit 47 = 1, Line 47 has
warning
7.7.10 FC18
FC18 is shown in FC18 Register and described in FC18 Register Field Descriptions.
Figure 7-38. FC18 Register
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
6
5
4
3
2
1
0
22
21
20
19
18
17
16
RESERVED
R-0b
15
14
13
12
11
10
9
8
7
RESERVED
R-0b
31
30
29
28
27
26
25
24
23
LSD_LINE_WARN[63:48]
R-0b
Table 7-16. FC18 Register Field Descriptions
Bit
Field
Type
Reset
Description
47-0
LSD_LINE_WARN[63:48]
R
0b
Read the line with LED short circuitry warnings:
Bit 0 = 0, Line 48 has no warning; Bit 0 = 1, Line 48 has warning
...
Bit 15 = 0, Line 63 has no warning; Bit 15 = 1, Line 63 has
warning
47-16
RESERVED
R
0b
Reserved bits
7.7.11 FC19
FC19 is shown in FC19 Register and described in FC19 Register Field Descriptions.
Figure 7-39. FC19 Register
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
21
20
19
18
17
16
5
4
3
2
1
0
LSD_LINE_WARN[47:0]
R-0b
31
30
29
28
27
26
25
24
23
22
LSD_LINE_WARN[47:0]
R-0b
15
14
13
12
11
10
9
8
7
6
LSD_LINE_WARN[47:0]
R-0b
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
47
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
Table 7-17. FC19 Register Field Descriptions
Bit
47-0
Field
Type
Reset
Description
LSD_LINE_WARN[47:0]
R
0b
Read the line with LED short circuitry warnings:
Bit 0 = 0, Line 0 has no warning; Bit 0 = 1, Line 0 has warning
...
Bit 47 = 0, Line 47 has no warning; Bit 47 = 1, Line 47 has
warning
7.7.12 FC20
FC20 is shown in FC20 Register and described in FC20 Register Field Descriptions.
Figure 7-40. FC20 Register
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
22
21
20
19
18
17
16
6
5
4
3
2
1
0
LOD_CH
R-0b
31
30
29
28
27
26
25
24
23
LOD_CH
R-0b
15
14
13
12
11
10
9
8
7
LOD_CH
R-0b
Table 7-18. FC20 Register Field Descriptions
Bit
47-0
Field
Type
Reset
Description
LOD_CH
R
0b
Locate the LED opem load channel:
Bit 0 = 0, CH 0 is normal; Bit 0 = 1, CH 0 is short circuitry
...
Bit 47 = 0, CH 47 is normal; Bit 47 = 1, CH 47 is short circuitry
7.7.13 FC21
FC21 is shown in FC21 Register and described in FC21 Register Field Descriptions.
Figure 7-41. FC21 Register
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
22
21
20
19
18
17
16
6
5
4
3
2
1
0
LSD_CH
R-0b
31
30
29
28
27
26
25
24
23
LSD_CH
R-0b
15
14
13
12
11
10
9
8
7
LSD_CH
R-0b
Table 7-19. FC21 Register Field Descriptions
Bit
47-0
48
Field
Type
Reset
Description
LSD_CH
R
0b
Locate the LED short circuitry channel:
Bit 0 = 0, CH 0 is normal; Bit 0 = 1, CH 0 is short circuitry
...
Bit 47 = 0, CH 47 is normal; Bit 47 = 1, CH 47 is short circuitry
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
8 Application and Implementation
Note
Information in the following applications sections is not part of the TI component specification,
and TI does not warrant its accuracy or completeness. TI’s customers are responsible for
determining suitability of components for their purposes, as well as validating and testing their design
implementation to confirm system functionality.
8.1 Application Information
The LP5891 integrates 48 constant current sources and 16 scanning FETs. A single LP5891 is capable of driving
16 × 16 RGB LED pixels while stacking two LP5891 devices can drive 32 × 32 RGB LED pixels. To achieve
low power consumption, the LP5891 supports separated power supplies for the red, green, and blue LEDs by its
common cathode structure.
The LP5891 implements a high speed rising edge transmission interface (up to 50 MHz) to support high device
count daisy-chained and high refresh rate while minimizing electrical-magnetic interference (EMI). SCLK must
be continuous, no matter there is data on SIN or not, because SCLK is not only used to sample the data on
SIN, but also used as a clock source to generate GCLK by internal frequency multiplier. Based on rising-edge
CCSI protocol, all the commands/FC registers/SRAM data are written from the SIN input terminal, and all the
FC registers/ LED open and short flag can be read out from the SOUT output terminal. Moreover, the device
supports up to 160-MHz GCLK frequency and can achieve 16-bit PWM resolution, with 3840 Hz or even higher
refresh rate.
Meanwhile, the LP5891 integrates enhanced circuits and intelligent algorithms to solve the various display
challenges in Narrow Pixel Pitch (NPP) LED display applications and mini and micro-LED products: dim at the
first scan line, upper and downside ghosting, non-uniformity in low grayscale, coupling, caterpillar caused by
open or short LEDs, which make the LP5891 a perfect choice in such applications.
The LP5891 also implements LED open, weak short, short detections and removals during operations and can
also report this information out to the accompanying digital processor.
8.2 Typical Application
The LP5891 are typically connected in series in a daisy-chain to drive the LED matrix with only a few controller
ports. Figure 8-1 shows a typical application diagram with two LP5891 devices stackable connection to drive 32
× 32 RGB LED pixels.
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
49
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
Figure 8-1. LP5891 with Dual Devices Stackable Connection
8.2.1 Design Requirements
Taking 4K micro-LED television for example, the resolution of the screen is 3840 × 2160, and the screen
consists of many modules. The following sections show an example to build a LED display module with 240 ×
180 pixels.
The example uses the following values as the system design parameters.
Table 8-1. LP5891 Design Parameters
DESIGN PARAMETER
EXAMPLE VALUE
VCC and VR
2.8 V
VG and VB
3.8 V
Maximum current per LED
IRED = 3 mA, IGREEN = 2 mA, IBLUE = 1 mA
PWM resolution
14 bits
Frame rate
120 Hz
Refresh rate
3840 Hz
Display module size
240 × 180 pixels
cascaded devices number
8
devices number per LED display module
96
8.2.1.1 System Structure
To build an LED display module with 240 × 180 pixels, 96 LP5891 devices are required.
50
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
240 Columns
30 x 30
pixels
30 x 30
pixels
30 x 30
pixels
30 x 30
pixels
30 x 30
pixels
30 x 30
pixels
30 x 30
pixels
30 x 30
pixels
30 x 30
pixels
30 x 30
pixels
30 x 30
pixels
30 x 30
pixels
30 x 30
pixels
30 x 30
pixels
30 x 30
pixels
30 x 30
pixels
30 x 30
pixels
30 x 30
pixels
30 x 30
pixels
30 x 30
pixels
30 x 30
pixels
30 x 30
pixels
30 x 30
pixels
30 x 30
pixels
30 x 30
pixels
30 x 30
pixels
30 x 30
pixels
30 x 30
pixels
30 x 30
pixels
30 x 30
pixels
30 x 30
pixels
30 x 30
pixels
30 x 30
pixels
30 x 30
pixels
30 x 30
pixels
30 x 30
pixels
30 x 30
pixels
30 x 30
pixels
30 x 30
pixels
30 x 30
pixels
30 x 30
pixels
30 x 30
pixels
30 x 30
pixels
30 x 30
pixels
30 x 30
pixels
30 x 30
pixels
30 x 30
pixels
30 x 30
pixels
180
Lines
Figure 8-2. LED Display Module
As shown in Figure 8-2, the total module can be divided into 48 32 × 32 matrix. Each matrix includes two devices
with stackable connection.
Note
To achieve the best performance, distribute the redundant channels and lines to each 32 × 32 matrix.
For this case, two Red/Green/Blue channels and two lines are not used in each matrix. And these
unused pins can be floated. For the software, TI suggests zero data to send to the unused channels.
There is no need to send the zero data to unused lines.
8.2.1.2 SCLK Frequency
The SCLK frequency is determined by the data volume of one frame and frame rate. In this application, the data
volume V_Data is 30 × 32 × 48 bits × 4 = 184.32 Kb, the frame rate is 120 Hz. Suppose the data transmission
efficiency is 0.8, the minimum frequency of SCLK must be: fSCLK = V_Data × fframe / 0.8. So the minimum SCLK
frequency is 27.65 MHz with rising-edge transmission.
8.2.1.3 Internal GCLK Frequency
The internal GCLK frequency is configured by the Frequency Multiplier (FREQ_MUL), and is determined by the
PWM resolution. The GCLK frequency can be calculated by the below equations:
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
51
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
f refresh _ rate
N sub _ period
f frame _ rate
GS max
2K
GSmax
N GCLK _ Seg u N sub _ period
1
f frame _ rate
§ N GCLK _ Seg
¨
© fGCLK
·
TSW ¸ u N Scan _ line u N sub _ period
¹
TBlank
(3)
where
•
•
•
•
•
•
•
•
•
•
frefresh_rate means the refresh rate
fframe_rate means the frame rate
K means the PWM resolution
Nsub_period means the sub-period numbers within one frame
NGCLK_seg means the GCLK number per segment (line switch time excluded)
fGCLK means GCLK frequency
TSW means line switching time
Nscan_line means the scan line number
Tblank means the blank time in one frame, equals to 0 in ideal configuration
GSmax means the maximum grayscale that the device can output in one frame
Table 8-2 gives the values based on the system configuration and equation.
Table 8-2. LP5891 Design Parameters for GCLK Frequency Calculation
DESIGN PARAMETER
EXAMPLE VALUE
Nsub_period
32
Nscan_line
30
TSW
1.5 µs
Tblank
0
NGCLK_seg
512
GSmax
16383
fGCLK
71.3 MHz
Considering SCLK frequency and FREQ_MUL, the SCLK can be 27.7 MHz, and FREQ_MUL can be 0010b. So
the GCLK is 83.1 MHz.
8.2.1.4 Line Switch Time
The line switch time is digitalized with the GCLK number and can be set by the LINE_SWT (Bit 40-37 in FC1
register). In this application, it is 1.5 us × 83.1 MHz = 125 GCLKs, so the LINE_SWT equals to 0011b (120
GCLKs), the actual line switch time is 1.44 us.
8.2.1.5 Blank Time Removal
The LP5891 has an algorithm to distribute the blank time into each sub-period to prevent the black field when
taking photos or video.
From Equation 3, 83.1-MHz GCLK frequency and 1.44-us line switch time, the calculated blank time is 1.0361
ms ( 86100 GCLK ), which is too long and brings black field.
Here are detailed steps of the algorithm.
Step 1: Distribute blank time into each segment
52
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
When the blank GCLK number is larger than Nsub_period × Nscan_line, it can be distributed into each segment.
In this application, the blank GCLK number is 86100, and Nsub_period × Nscan_line is 960, so the distributed GCLK
number in each segment is 86100/960 = 89...660. These 89 GCLKs can be used to increase PWM length or
extend line switch time. If used to increase PWM length, the GCLK number in each segment will be 512 + 89 =
601, so the SEG_LENGTH ( Bit9-0 in FC1 register) is 1001011001b.
Step 2: Distribute blank time into each sub-period
If the left GCLK number is larger than Nsub_period, it can be distributed into each sub-period.
In this application, the left GCLK is 660, the distributed GCLK number in each sub-period is 660/32=20. The
BLK_ADJ (Bit46-41 in FC1 register) is 010100b.
After distributing into each sub-period, the left GCLK number is 0.
8.2.1.6 BC and CC
Select the reference current-setting resistor RIREF and configure a proper BC value to set the maximum current
of the RGB LEDs (see Brightness Control (BC) Function for more details). Here the maximum current is 3 mA,
BC value is 03h, according to equation Equation 1, the reference resistor value is 0.8 V/3 mA × 86.61 = 23 kΩ.
Configure the CC_R/CC_G/CC_B registers to set the current of Red/Green/Blue LED current to 3 mA/2 mA/1
mA (see Color Brightness Control (CC) Function for more details).
Table 8-3 shows the reference current setting resistor RIREF, BC and CC_R/CC_G/CC_B register value.
Table 8-3. Current Setting Value
DESIGN PARAMETER
EXAMPLE VALUE
RIREF
23 kΩ
BC
011 b
CC_R
11111110 b
CC_G
10101001 b
CC_B
01010100 b
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
53
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
8.2.2 Detailed Design Procedure
Figure 8-3 gives a detail design procedure for LED display. After power on and digital signals are ready, the
first step for the controller is to send the chip index command to let the devices know their identifications. Then,
the command sends the configuration data to the FC registers. After this, it sends the VSYNC at the beginning
of each frame and also sends the data to each device. The devices displays the data of last frame when the
VSYNC comes and meanwhile receive the data of current frame transmitted from controller. The registers can
be read at anytime of the frame.
Begin
Power Supply, SCLK/SIN
Ready
Write Chip Index
Configure the
register during
sending data
Write FC Registers
Write next
frame SRAM
Data in normal
operation
Write SRAM
Wait for the end of current
frame
Write VSYNC
Read Chip Index/FC/LOD/LSD
Read registers
during each
time of the
frame
Figure 8-3. Design Procedure for LED Display
8.2.2.1 Chip Index Command
The chip index is used to distribute the address of the devices in a data chain,. Each device gets its unique
address by this command. Details can be found in Chip Index Write Command.
8.2.2.2 FC Registers Settings
Some bits of FC0, FC1, FC2, FC3 registers must be configured properly before the devices work normally. In
this application, the registers value can be:
Table 8-4. FC Registers Value
FC Registers
Register Value(BIN)
Register Value(HEX)
FC0
0001 0000 0000 0000 0101 1000 0011 1111 0000 0001 0000 0111 b
1000 583F 0107 h
FC1
0010 1010 1110 0000 0000 0000 1001 0100 1010 0110 0011 0001 b
2AE0 0094 A631 h
FC2
0000 1000 0000 0000 0000 0000 0000 1111 0000 0110 0110 0110 b
0800 000F 0666 h
FC3
0000 0000 0011 1011 0101 0100 1010 1001 1111 1111 0000 0000 b
003B 54A9 FF00 h
The controller can configure the FC by the data write command with broadcast mode (see Data Write Command
for more detail), the FC0, FC1 registers are updated after the VSYNC command comes, and the other FC
registers are updated right away regardless the VSYNC command.
54
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
8.2.2.3 Grayscale Data Write
The channel grayscale data is written to SRAM of the device by the data write command with non-broadcast
way, details can be found in Data Write Command and Write a Frame Data into Memory Book.
Data Write Flow is the data write flow for this application, P (i, j) is the data of pixel locating in I + 1 row and
j + 1 column. Suppose channel R15/G15/B15 of each device is not used and not connected, the channel
R14/G14/B14 is connected to P(i, 0), the channel R13/G13/B13 is connected to P (i, 1),…, and channel
R0/G0/B0 is connected to P (i, 14). The data of unused channel must be zero noting D_Zero in below figure, and
D_Zero = 00000000000000001 00000000000000001 00000000000000001b.
i=0
j=15
ST+HB+P(i, jx7)+P(i, jx6)+Y+P(i, jx1)+P(i,0)+END
j=j-1
N
Write one
line data
Write one
frame data
j=0
Y
ST+HB+D_Zero+D_Zero+Y+D_Zero+D_Zero+END
i=i+1
N
i=30
Y
Figure 8-4. Data Write Flow
8.2.2.4 VSYNC Command
The VSYNC is used to sync the display of each frame for the devices in a cascaded chain. Details can be found
in VSYNC Write Command.
8.2.2.5 LED Open/Short Read
FC14, FC15, FC16, FC17, FC18, FC19, FC20, FC21 are the read command for LOD/LSD information. Details
can be found in Read LED-open Information and Read LED-short Information.
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
55
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
8.2.3 Application Curves
56
Figure 8-5. Line and Channel Waveform in One
Frame (GSn=0xFFFFh)
Figure 8-6. Line and Channel Waveform in One
Subperiod (GSn=0xFFFFh)
Figure 8-7. Line and Channel Waveform in One
Frame (GSn=0x0001h)
Figure 8-8. Line and Channel Waveform in One
Frame (GSn=0x0001h)
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
9 Power Supply Recommendations
Decouple the VCC power supply voltage by placing a 0.1-μF ceramic capacitor close to VCC pin and GND
plane. Depending on panel size, several electrolytic capacitors must be placed on the board equally distributed
to get well regulated LED supply voltage VR/VG/VB. The ripple of the LED supply voltage must be less than
5% of their nominal value. Generally, the green and blue LEDs have the similar forward voltage, they can be
supplied by the same power rail.
Furthermore, the VR > Vf(R) + 0.35 V (10-mA constant current example), the VG = VB > Vf (G/B) + 0.35 V
(10-mA constant current example), here Vf(R), Vf(G/B) are representative for the maximum forward voltage of
red, green/blue LEDs.
To simplify the power design, VCC can be connected to the VR power rail.
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
57
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
10 Layout
10.1 Layout Guidelines
•
•
•
•
•
•
Place the decoupling capacitor near the VCC/VR, VG/VB pins and GND plane.
Place the current programming resistor RIREF close to IREF pin and GND plane.
Route the GND thermal pad as widely as possible for large GND currents. Maximum GND current is
approximately 2 A for two devices (96-CH × 20 mA = 1.92 A).
The Thermal Pad must be connected to GND plane because the pad is used as power ground pin internally.
There is a large current flow through this pad when all channels turn on. Furthermore, this pad must be
connected to a heat sink layer by thermal via to reduce device temperature. For more information about
suggested thermal via pattern and via size, see PowerPAD™ Thermally Enhanced Package application note.
Routing between the LED Anode side and the device OUTXn pin must be as short and straight as possible to
reduce wire inductance.
The line switch pins must be located in the middle of the matrix, which must be laid out as symmetrically as
possible.
10.2 Layout Example
To simplify the system power rails design, VR, VCC must use one power rail and VG, VB use another power rail.
Figure 10-1 gives an example for power rails routing.
Connect the GND pin to the thermal pad on the board with the shortest wire and the thermal pad is connected to
GND plane with the vias, as many as possible to help the power dissipation.
32 RGB LEDs
GND
VR
VCC
C
VR
VR/VCC
C
GND
GND
TLC6983
GND
VG
VG
GND
VB
C
VB
GND
C
32 Lines
VG/VB
VB
VB
VG
C
VG
C
GND
GND
TLC6983
GND
GND
VR
VR
VCC
GND
GND
C
C
VR/VCC
Figure 10-1. Power Rails Routing Suggestion
Figure 10-2 gives an example for line routing. Connect the line switch to the center of the line bus, so as to
uniform the current flowing from the line switch to the left side and right side LEDs in white grayscale. With this
connection, the unbalance of the parasitic inductor from the routing is the smallest and the display performance
is better, especially in low grayscale condition.
58
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
Figure 10-2. Line Routing Suggestion
Figure 10-3 gives an example for channel routing with the shortest wire. With this connection, the channel to the
LED path is the shortest, which can reduce the wire inductance, and be a benefit to the performance. However,
the data transmission sequence must be adjusted to follow the pins routing map. For example, R0 connects to
column 15 (LED15 ). The first data must be column 15 (LED15) rather than column 0 (LED0).
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
59
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
Figure 10-3. Channel Routing Suggestion with Shortest Wire
Figure 10-4 gives an example for channel routing with pin number sequence. With this connection, the data
transmission sequence is the same with pin number sequence. For example, R0 connects to column 0 (LED0 ).
The first data is column 0 (LED0). However, with this connection, the inductance for each channel can be
different, which can bring a slight difference for the worst case.
60
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
Figure 10-4. Channel Routing Suggestion with Channel Order Sequence
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
61
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
11 Device and Documentation Support
11.1 Documentation Support
11.1.1 Related Documentation
Texas Instruments, PowerPAD™ Thermally Enhanced Package application note
11.2 Receiving Notification of Documentation Updates
To receive notification of documentation updates, navigate to the device product folder on ti.com. Click on
Subscribe to updates to register and receive a weekly digest of any product information that has changed. For
change details, review the revision history included in any revised document.
11.3 Support Resources
TI E2E™ support forums are an engineer's go-to source for fast, verified answers and design help — straight
from the experts. Search existing answers or ask your own question to get the quick design help you need.
Linked content is provided "AS IS" by the respective contributors. They do not constitute TI specifications and do
not necessarily reflect TI's views; see TI's Terms of Use.
11.4 Trademarks
TI E2E™ is a trademark of Texas Instruments.
All trademarks are the property of their respective owners.
11.5 Electrostatic Discharge Caution
This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled
with appropriate precautions. Failure to observe proper handling and installation procedures can cause damage.
ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may
be more susceptible to damage because very small parametric changes could cause the device not to meet its published
specifications.
11.6 Glossary
TI Glossary
62
This glossary lists and explains terms, acronyms, and definitions.
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
LP5891
www.ti.com
SLDS269A – MARCH 2022 – REVISED MAY 2022
12 Mechanical, Packaging, and Orderable Information
The following pages include mechanical, packaging, and orderable information. This information is the most
current data available for the designated devices. This data is subject to change without notice and revision of
this document. For browser-based versions of this data sheet, refer to the left-hand navigation.
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
Product Folder Links: LP5891
63
PACKAGE OPTION ADDENDUM
www.ti.com
18-Aug-2022
PACKAGING INFORMATION
Orderable Device
Status
(1)
Package Type Package Pins Package
Drawing
Qty
Eco Plan
(2)
Lead finish/
Ball material
MSL Peak Temp
Op Temp (°C)
Device Marking
(3)
Samples
(4/5)
(6)
LP5891MRRFR
ACTIVE
VQFN
RRF
76
2000
RoHS & Green
NIPDAU
Level-3-260C-168 HR
-55 to 125
LP5891M
Samples
LP5891RRFR
ACTIVE
VQFN
RRF
76
2000
RoHS & Green
NIPDAU
Level-3-260C-168 HR
-40 to 85
LP5891
Samples
LP5891ZXLR
ACTIVE
NFBGA
ZXL
96
2500
RoHS & Green
SNAGCU
Level-3-260C-168 HR
-40 to 85
LP5891
Samples
(1)
The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2)
RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance
do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may
reference these types of products as "Pb-Free".
RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption.
Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of