IS31FL3191
1-CHANNEL FUN LED DRIVER
July 2021
GENERAL DESCRIPTION
FEATURES
IS31FL3191 is a 1-channel fun LED driver which has
One Shot Programming mode and PWM Control mode
for LED lighting effects. The maximum output current
can be adjusted in 5 levels (5mA~42mA).
In PWM Control mode, the PWM duty cycle of each
output can be independently programmed and
controlled in 256 steps to simplify color mixing. In One
Shot Programming mode, the timing characteristics for
output current - current rising, holding, falling and off
time, can be adjusted individually.
IS31FL3191 is available in UTQFN-9 (1.5mm × 1.5mm).
It operates from 2.7V to 5.5V over the temperature
range of -40°C to +85°C.
Independently controlled automatic and
semiautomatic breathing system-free preestablished pattern
I2C interface, automatic address increment
function
Independently controlled output of 256 PWM
steps
2.7V to 5.5V supply voltage
5 levels programmable output current
Over-temperature protection
Operating temperature TA = −40°C ~ +85°C
UTQFN-9 (1.5mm × 1.5mm) package
APPLICATIONS
Mobile phones and other hand-held devices for
LED display
LED in home appliances
TYPICAL APPLICATION CIRCUIT
Figure 1
Typical Application Circuit
Note: The IC should be placed far away from the mobile antenna in order to prevent the EMI.
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IS31FL3191
PIN CONFIGURATION
Package
Pin Configuration (Top View)
UTQFN-9
PIN DESCRIPTION
No.
Pin
Description
A1
SDB
Shutdown the chip when pulled to low.
A2, A3
NC
No connection.
B1, B2
GND
Ground.
B3
SDA
I2C serial data.
C1
OUT
Current source output.
C2
VCC
Power supply.
C3
SCL
I2C serial clock.
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IS31FL3191
ORDERING INFORMATION
Industrial Range: -40°C to +85°C
Order Part No.
Package
QTY/Reel
IS31FL3191-UTLS2-TR
UTQFN-9, Lead-free
3000
Copyright © 2021 Lumissil Microsystems. All rights reserved. Lumissil Microsystems reserves the right to make changes to this specification and its products
at any time without notice. Lumissil Microsystems assumes no liability arising out of the application or use of any information, products or services described
herein. Customers are advised to obtain the latest version of this device specification before relying on any published information and before placing orders
for products.
Lumissil Microsystems does not recommend the use of any of its products in life support applications where the failure or malfunction of the product can
reasonably be expected to cause failure of the life support system or to significantly affect its safety or effectiveness. Products are not authorized for use in
such applications unless Lumissil Microsystems receives written assurance to its satisfaction, that:
a.) the risk of injury or damage has been minimized;
b.) the user assume all such risks; and
c.) potential liability of Lumissil Microsystems is adequately protected under the circumstances
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IS31FL3191
ABSOLUTE MAXIMUM RATINGS
Supply voltage, VCC
Voltage at any input pin
Maximum junction temperature, TJMAX
Operating temperature range, TA
Storage temperature range, TSTG
ESD (HBM)
ESD (CDM)
-0.3V ~ +6.0V
-0.3V ~ VCC+0.3V
150°C
-40°C ~ +85°C
-65°C ~ +150°C
±8kV
±1kV
Note: Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings
only and functional operation of the device at these or any other condition beyond those indicated in the operational sections of the specifications
is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
TA = -40°C ~ +85°C, VCC = 5V, unless otherwise noted. Typical value are TA = 25°C.
Symbol
Parameter
Condition
VCC
Supply voltage
ICC
Quiescent power supply current VSDB = VCC
ISD
Shutdown current
VSDB = 0V or software shutdown
IOUT
Output current
PWM Control mode, VDS = 0.5V
PWM Register(04h) = 0xFF
Current Register(03h) = 0x00
VHR
Current sink headroom voltage
IOUT = 42mA
Min.
Typ.
2.7
Max.
Unit
5.5
V
0.36
mA
2.5
μA
42
(Note 1)
mA
500
mV
Logic Electrical Characteristics (SDA, SCL, SDB, AD)
VIL
Logic “0” input voltage
VCC = 2.7V
VIH
Logic “1” input voltage
VCC = 5.5V
IIL
Logic “0” input current
5
(Note 2)
nA
IIH
Logic “1” input current
5
(Note 2)
nA
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Rev. C, 07/05/2021
0.4
1.4
V
V
4
IS31FL3191
DIGITAL INPUT SWITCHING CHARACTERISTICS (Note 3)
Symbol
Parameter
Condition
Min.
Typ.
Max.
Unit
400
kHz
fSCL
Serial-Clock frequency
tBUF
Bus free time between a STOP and a
START condition
1.3
μs
tHD, STA
Hold time (repeated) START condition
0.6
μs
tSU, STA
Repeated START condition setup time
0.6
μs
tSU, STO
STOP condition setup time
0.6
μs
tHD, DAT
Data hold time
tSU, DAT
Data setup time
100
ns
tLOW
SCL clock low period
1.3
μs
tHIGH
SCL clock high period
0.7
μs
0.9
μs
tR
Rise time of both SDA and SCL signals,
receiving
(Note 4)
20+0.1Cb
300
ns
tF
Fall time of both SDA and SCL signals,
receiving
(Note 4)
20+0.1Cb
300
ns
Note 1: IOUT represents the average output current. See PWM Register, Table 7.
Note 2: The LED is on.
Note 3: Guaranteed by design.
Note 4: Cb = total capacitance of one bus line in pF. ISINK ≤ 6mA. tR and tF measured between 0.3 × VCC and 0.7 × VCC.
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IS31FL3191
DETAILED DESCRIPTION
I2C INTERFACE
After the last bit of the chip address is sent, the master
checks for the IS31FL3191’s acknowledge. The master
releases the SDA line high (through a pull-up resistor).
Then the master sends an SCL pulse. If the
IS31FL3191 has received the address correctly, then it
holds the SDA line low during the SCL pulse. If the SDA
line is not low, then the master should send a “STOP”
signal (discussed later) and abort the transfer.
The IS31FL3191 uses a serial bus, which conforms to
the I2C protocol, to control the chip’s functions with two
wires: SCL and SDA. The IS31FL3191 has a 7-bit slave
address (A7:A1), followed by the R/W bit, A0. Since
IS31FL3191 only supports write operations, A0 must
always be “0”.
The complete slave address is:
Following acknowledge of IS31FL3191, the register
address byte is sent, most significant bit first.
IS31FL3191 must generate another acknowledge
indicating that the register address has been received.
Table 1 Slave Address (Write Only):
Bit
A7:A1
A0
Value
1101 000
0
Then 8-bit of data byte are sent next, most significant
bit first. Each data bit should be valid while the SCL
level is stable high. After the data byte is sent, the
IS31FL3191 must generate another acknowledge to
indicate that the data was received.
The SCL line is uni-directional. The SDA line is bidirectional (open-collector) with a pull-up resistor
(typically 4.7kΩ). The maximum clock frequency
specified by the I2C standard is 400kHz. In this
discussion, the master is the microcontroller and the
slave is the IS31FL3191.
The “STOP” signal ends the transfer. To signal “STOP”,
the SDA signal goes high while the SCL signal is high.
ADDRESS AUTO INCREMENT
The timing diagram for the I2C is shown in Figure 2. The
SDA is latched in on the stable high level of the SCL.
When there is no interface activity, the SDA line should
be held high.
The “START” signal is generated by lowering the SDA
signal while the SCL signal is high. The start signal will
alert all devices attached to the I2C bus to check the
incoming address against their own chip address.
To write multiple bytes of data into IS31FL3191, load
the address of the data register that the first data byte
is intended for. During the IS31FL3191 acknowledge of
receiving the data byte, the internal address pointer will
increment by one. The next data byte sent to
IS31FL3191 will be placed in the new address, and so
on (Figure 5).
The 8-bit chip address is sent next, most significant bit
first. Each address bit must be stable while the SCL
level is high.
Figure 2
Figure 3
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Interface Timing
Bit Transfer
6
IS31FL3191
Figure 4
1
2
3
A7 A6 A5
SDA
SCL
4
5
6
7
8
A4 A3 A2 A1 A0
9
A
Writing to IS31FL3191 (Typical)
1
2
3
4
5
A7 A6 A5 A4 A3
6
7
8
A2 A1 A0
9
A
1
2
D7 D6
3
4
5
6
7
D5 D4 D3 D2 D1
8
D0
9
A
S
Start
by
Master
Ack
by
IS31FL3191
IS31FL3191 Address Byte
9
A
1
2
3
4
5
D7 D6 D5 D4 D3
Register Address Byte
6
7
8
D2 D1 D0
9
A
1
2
D7 D6
Ack
by
IS31FL3191
Ack
by
IS31FL3191
Data 1 Byte
3
4
5
6
7
D5 D4 D3 D2 D1
8
D0
9
A
P
Ack
by
IS31FL3191
Data (n-1) Byte
Figure 5
Ack
by
IS31FL3191
Ack
Stop
by
by
IS31FL3191 Master
Data n Byte
Writing to IS31FL3191 (Automatic Address Increment)
REGISTERS DEFINITIONS
Table 2 Register Function
Address
Name
Function
R/W
Table
Default
0000 0001
00h
Shutdown Register
Set software shutdown mode
3
01h
Breathing Control Register
Set the breathing function
4
02h
LED Mode Register
Set operation mode
5
03h
Current Setting Register
6
04h
PWM Register
07h
PWM Update Register
Set output current
Channel PWM duty cycle
registers
Load PWM Registers data
0Ah
T0 Register
Set the T0 time
8
10h
T1&T2 Register
Set the T1&T2 time
9
16h
T3&T4 Register
Set the T3&T4 time
10
1Ch
Time Update Register
Load time registers’ data
1Dh
LED Control Register
OUT enable bit
2Fh
Reset Register
Reset all registers to default value
Table 3
00h Shutdown Register
Bit
D7:D6
D5
D4:D1
D0
Name
-
EN
-
SSD
Default
00
0
0000
1
The Shutdown Register sets software shutdown mode
of IS31FL3191.
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data
0000 0000
7
W
-
xxxx xxxx
0000 0000
-
xxxx xxxx
11
0000 0001
-
xxxx xxxx
EN
0
1
Channel Control
Channel disable
Channel enable
SSD
0
1
Software Shutdown Enable
Normal operation
Software shutdown mode
7
IS31FL3191
Table 4
Bit
01h Breathing Control Register
D7:D6
D5
D4
D3:D0
Name
RM
HT
Defaul
00
0
0
0000
t
The Breathing Control Register sets the breathing
function.
RM
0
1
Ramping Mode Enable
Disable
Enable
Hold Time Selection
Hold on T2
Hold on T4
Table 5
02h LED Mode Register
D7:D6
D5
D4:D0
Name
LED
Defaul
00
0
00000
t
The LED Mode Register sets operation mode of
IS31FL3191.
LED
0
1
LED Mode Selection
PWM Control Mode
One Shot Programming Mode
Table 6
03h Current Setting Register
Bit
D7:D5
Bit
D7:D0
Name
PWM
Default
0000 0000
The value in the PWM Registers modulate the LEDs in
256 steps.
The value of the PWM Register decides the average
output current. The average output current may be
computed using the Formula (1):
D4:D2
D1:D0
Current Setting
42mA
10mA
5mA
30mA
17.5mA
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I MAX 7
D[n] * 2 n
256 n0
(1)
Where D[n] stands for the individual bit value, 1 or 0, in
location n.
For example: if D7:D0 = 10110101,
IOUT = IMAX (20+22+24+25+27)/256
IMAX is set by Current Setting Register.
07h PWM Update Register
The data sent to the PWM Registers will be stored in
temporary registers. A write operation of “0000 0000”
value to the PWM Update Register is required to
update the registers (04h).
Table 8
Name
CS
Defaul
000
000
00
t
The Current Setting Register stores the maximum
current setting, IMAX, for all of the LED output channels.
CS
000
001
010
011
1xx
04h PWM Register
I OUT
HT
0
1
Bit
Table 7
0Ah
T0 Register
Bit
D7:D4
D3:D0
Name
T0
-
Default
0000
0000
The T0 Registers set the T0 time in One Shot
Programming mode.
T0
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
Others
T0 Setting
0s
0.13s
0.26s
0.52s
1.04s
2.08s
4.16s
8.32s
16.64s
33.28s
66.56s
Unavailable
8
IS31FL3191
Table 9
10h T1&T2 Register
Bit
D7:D5
D4:D1
D0
Name
T1
T2
Defaul
000
0000
0
t
The T1&T2 Registers set the T1&T2 time in One Shot
Programming mode.
T1
000
001
010
011
100
101
110
111
T1 Setting
0.13s
0.26s
0.52s
1.04s
2.08s
4.16s
8.32s
16.64s
T2
0000
0001
0010
0011
0100
0101
0110
0111
1000
Others
T2 Setting
0s
0.13s
0.26s
0.52s
1.04s
2.08s
4.16s
8.32s
16.64s
Unavailable
Table 10
T4 Setting
0s
0.13s
0.26s
0.52s
1.04s
2.08s
4.16s
8.32s
16.64s
33.28s
66.56s
Unavailable
1Ch Time Update Register
The data sent to the time registers will be stored in
temporary registers. A write operation of “0000 0000”
value to the Time Update Register is required to update
the registers (0Ah, 10h, 16h).
Table 11 1Dh LED Control Register
Bit
D7:D1
D0
Name
-
OUT
Default
0000 000
1
The LED Control Registers store the on or off state of
each channel LED.
OUT
0
1
16h T3&T4 Register
Bit
D7:D5
D4:D1
D0
Name
T3
T4
-
Default
000
0000
0
The T3&T4 Registers set the T3&T4 time in One Shot
Programming mode.
T3
000
001
010
011
100
101
110
111
T4
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
Others
LED State
LED off
LED on
2Fh Reset Register
Once user writes “0000 0000” to the Reset Register,
IS31FL3191 will reset all registers to their default value.
On initial power-up, the IS31FL3191 registers are reset
to their default values for a blank display.
T3 Setting
0.13s
0.26s
0.52s
1.04s
2.08s
4.16s
8.32s
16.64s
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IS31FL3191
FUNCTIONAL BLOCK DIAGRAM
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IS31FL3191
APPLICATION INFORMATION
GENERAL DESCRIPTION
SEMIAUTOMATIC BREATHING
IS31FL3191 is a 1-channel LED driver with twodimensional auto breathing and PWM Control mode. It
can drive one individual LED.
By setting the LED bits of the LED Mode Register (02h)
to “1” and the RM bit of the Breathing Control Register
(01h) to “1”, the ramping function is enabled. HT is the
time select bit. When HT bit is set to “0”, T2 will be held
forever, and the LED will remain at the programmed
maximum intensity. When HT bit is set to “1”, T3 will
continue and T4 will be held, causing the LED to
complete one breathing cycle and then remain off.
PWM CONTROL
By setting the LED bits of the LED Mode Register (03h)
to “0”, the IS31FL3191 will operate in PWM Control
mode. The PWM Registers (04h) can modulate LED
brightness of one channel with 256 steps. For example,
if the data in PWM Register is “0000 0100”, then the
PWM is the fourth step, with a duty cycle of 4/256.
In PWM control mode, a new value must be written to
the PWM registers to change the output PWM duty
cycle. Writing new data continuously to the registers
can modulate the brightness of the LEDs to achieve a
breathing effect, blinking, or any other effects that the
user defines.
LED BREATHING CONTROL
By setting the LED bits of the LED Mode Register (03h)
to “1”, the IS31FL3191 will operate in One Shot
Programming mode. In this mode, PWM Registers (04h)
are unavailable and the LED intensity is automatically
modulated in a breathing cycle, independently
controlled by T0~T4. T0 is an offset time period which
runs only once at the start of the cycle. The full cycle
is T1 to T4 (Figure 6).
Figure 6
SHUTDOWN MODE
Shutdown mode can either be used as a means of
reducing power consumption or generating a flashing
display (repeatedly entering and leaving shutdown
mode). During shutdown mode all registers retain their
data.
Software Shutdown
By setting SSD bit of the Shutdown Register (00h) to
“1”, the IS31FL3191 will operate in software shutdown
mode, wherein they consume only 3.5μA (Typ.) current.
When the IS31FL3191 is in software shutdown mode,
all current sources are switched off.
Hardware Shutdown
The chip enters hardware shutdown mode when the
SDB pin is pulled low, wherein they consume only
2.5μA (Typ.) current.
Breathing Timing
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IS31FL3191
CLASSIFICATION REFLOW PROFILES
Profile Feature
Pb-Free Assembly
Preheat & Soak
Temperature min (Tsmin)
Temperature max (Tsmax)
Time (Tsmin to Tsmax) (ts)
150°C
200°C
60-120 seconds
Average ramp-up rate (Tsmax to Tp)
3°C/second max.
Liquidous temperature (TL)
Time at liquidous (tL)
217°C
60-150 seconds
Peak package body temperature (Tp)*
Max 260°C
Time (tp)** within 5°C of the specified
classification temperature (Tc)
Max 30 seconds
Average ramp-down rate (Tp to Tsmax)
6°C/second max.
Time 25°C to peak temperature
8 minutes max.
Figure 7
Classification Profile
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IS31FL3191
PACKAGE INFORMATION
UTQFN-9
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IS31FL3191
RECOMMENDED LAND PATTERN
Note:
1. Land pattern complies to IPC-7351.
2. All dimensions in MM.
3. This document (including dimensions, notes & specs) is a recommendation based on typical circuit board manufacturing parameters. Since
land pattern design depends on many factors unknown (eg. user’s board manufacturing specs), user must determine suitability for use.
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IS31FL3191
REVISION HISTORY
Revision
Detail Information
Date
A
Initial release
2012.07.05
B
1. Update I2C writing figure
2. Add land pattern
3. Add ESD value
4. Add functional block
2015.07.10
C
Add EOL watermark
2021.07.05
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