SN74LXC8T245-Q1
SCES920B – SEPTEMBER 2020 – REVISED MARCH 2023
SN74LXC8T245-Q1 Automotive 8-bit Dual-Supply Bus Transceiver with Configurable
Level Shifting and 3-State Outputs
1 Features
3 Description
•
•
The SN74LXC8T245-Q1 is an 8-bit, dual-supply
noninverting bidirectional voltage level translation
device. Ax pins and control pins (DIR and OE) are
referenced to VCCA logic levels, and Bx pins are
referenced to VCCB logic levels. The A port is able to
accept I/O voltages ranging from 1.1 V to 5.5 V, while
the B port can accept I/O voltages from 1.1 V to 5.5
V. A high on DIR allows data transmission from A to
B and a low on DIR allows data transmission from B
to A when OE is set to low. When OE is set to high,
both Ax and Bx pins are in the high-impedance state.
See Device Functional Modes for a summary of the
operation of the control logic.
•
•
•
•
•
•
•
•
•
•
•
•
•
•
AEC-Q100 qualified for automotive applications
Fully configurable dual-rail design allows each port
to operate from 1.1 V to 5.5 V
Robust, glitch-free power supply sequencing
Up to 420-Mbps support for 3.3 V to 5.0 V
Schmitt-trigger inputs allow for slow or noisy inputs
I/Os with integrated dynamic pull-down resistors
help reduce external component count
Control inputs with integrated static pull-down
resistors allow for floating control inputs
High drive strength (up to 32 mA at 5 V)
Low power consumption:
– 4-µA maximum (25°C)
– 12-µA maximum (–40°C to 125°C)
VCC isolation and VCC disconnect (Ioff-float) feature:
– If either VCC supply is < 100 mV or
disconnected, all I/Os get pulled-down and then
become high-impedance
Ioff supports partial-power-down mode operation
Compatible with LVC family level shifters
Control logic (DIR and OE) are referenced to VCCA
Operating temperature from –40°C to +125°C
Latch-up performance exceeds 100 mA per JESD
78, Class II
ESD protection exceeds JESD 22
– 4000-V Human-Body Model
– 1000-V Charged-Device Model
Package Information
PACKAGE(1)
PART NUMBER
BODY SIZE (NOM)
PW (TSSOP, 24)
7.80 mm × 6.40 mm
SN74LXC8T245-Q1 RHL (VQFN, 24)
5.50 mm × 3.50 mm
DGS (VSSOP, 24)
(1)
6.10 mm × 3.00 mm
For all available packages, see the orderable addendum at
the end of the data sheet.
VCCB
VCCA
DIR
OE
2 Applications
•
•
•
•
•
Eliminate slow or noisy input signals
Driving indicator LEDs or buzzers
Debouncing a mechanical switch
Infotainment head unit
ADAS fusion
B1
A1
A8
To other 7 channels
GND
Functional Block Diagram
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.
B8
SN74LXC8T245-Q1
www.ti.com
SCES920B – SEPTEMBER 2020 – REVISED MARCH 2023
Table of Contents
1 Features............................................................................1
2 Applications..................................................................... 1
3 Description.......................................................................1
4 Revision History.............................................................. 2
5 Pin Configuration and Functions...................................3
6 Specifications.................................................................. 4
6.1 Absolute Maximum Ratings........................................ 4
6.2 ESD Ratings............................................................... 4
6.3 Recommended Operating Conditions.........................5
6.4 Thermal Information....................................................5
6.5 Electrical Characteristics.............................................6
6.6 Switching Characteristics, VCCA = 1.2 ± 0.1 V............ 9
6.7 Switching Characteristics, VCCA = 1.5 ± 0.1 V.......... 10
6.8 Switching Characteristics, VCCA = 1.8 ± 0.15 V........ 11
6.9 Switching Characteristics, VCCA = 2.5 ± 0.2 V.......... 12
6.10 Switching Characteristics, VCCA = 3.3 ± 0.3 V........ 13
6.11 Switching Characteristics, VCCA = 5.0 ± 0.5 V........ 14
6.12 Switching Characteristics: Tsk, TMAX ......................15
6.13 Operating Characteristics....................................... 15
6.14 Typical Characteristics............................................ 16
7 Parameter Measurement Information.......................... 17
7.1 Load Circuit and Voltage Waveforms........................17
8 Detailed Description......................................................19
8.1 Overview................................................................... 19
8.2 Functional Block Diagram......................................... 19
8.3 Feature Description...................................................20
8.4 Device Functional Modes..........................................22
9 Application and Implementation.................................. 23
9.1 Application Information............................................. 23
9.2 Typical Application.................................................... 23
9.3 Power Supply Recommendations.............................24
9.4 Layout....................................................................... 24
10 Device and Documentation Support..........................25
10.1 Documentation Support.......................................... 25
10.2 Receiving Notification of Documentation Updates..25
10.3 Support Resources................................................. 25
10.4 Trademarks............................................................. 25
10.5 Electrostatic Discharge Caution..............................25
10.6 Glossary..................................................................25
11 Mechanical, Packaging, and Orderable
Information.................................................................... 25
4 Revision History
NOTE: Page numbers for previous revisions may differ from page numbers in the current version.
Changes from Revision A (November 2020) to Revision B (March 2023)
Page
• Added DGS package information to the data sheet........................................................................................... 1
Changes from Revision * (September 2020) to Revision A (November 2020)
Page
• Changed status of data sheet from Advanced Information to Production Data .................................................1
2
Submit Document Feedback
Copyright © 2023 Texas Instruments Incorporated
Product Folder Links: SN74LXC8T245-Q1
SN74LXC8T245-Q1
www.ti.com
SCES920B – SEPTEMBER 2020 – REVISED MARCH 2023
OE
A7
9
16
B6
DIR
A1
A2
A3
A4
A5
A6
A7
A8
A8
10
15
B7
GND
GND
11
14
B8
GND
12
13
GND
A2
4
21
B1
A3
5
20
B2
19
B3
A4
6
A5
7
18
B4
A6
8
17
B5
VCCB
22
24
3
2
23
3
22
4
21
5
20
6
19
PAD
7
18
8
17
9
16
10
15
11
14
13
VCCB
A1
GND
VCCB
23
VCCA
24
2
12
1
DIR
GND
VCCA
1
5 Pin Configuration and Functions
VCCB
OE
B1
B2
B3
B4
B5
B6
B7
B8
All packages are on the same relative scale.
Figure 5-1. PW, DGS, and RHL Package, 24-Pin TSSOP, VSSOP, and VQFN (Transparent Top View)
Table 5-1. Pin Functions
PIN
PW, DGS,
RHL
TYPE(1)
A1
3
I/O
Input or output A1. Referenced to VCCA.
A2
4
I/O
Input or output A2. Referenced to VCCA.
A3
5
I/O
Input or output A3. Referenced to VCCA.
A4
6
I/O
Input or output A4. Referenced to VCCA.
A5
7
I/O
Input or output A5. Referenced to VCCA.
A6
8
I/O
Input or output A6. Referenced to VCCA.
A7
9
I/O
Input or output A7. Referenced to VCCA.
A8
10
I/O
Input or output A8. Referenced to VCCA.
B1
21
I/O
Input or output B1. Referenced to VCCB.
B2
20
I/O
Input or output B2. Referenced to VCCB.
B3
19
I/O
Input or output B3. Referenced to VCCB.
B4
18
I/O
Input or output B4. Referenced to VCCB.
B5
17
I/O
Input or output B5. Referenced to VCCB.
B6
16
I/O
Input or output B6. Referenced to VCCB.
B7
15
I/O
Input or output B7. Referenced to VCCB.
B8
14
I/O
Input or output B8. Referenced to VCCB.
DIR
2
I
11
—
Ground.
GND
12
—
Ground.
13
—
Ground.
OE
22
I
VCCA
1
—
A-port supply voltage. 1.1 V ≤ VCCA ≤ 5.5 V.
23
—
B-port supply voltage. 1.1 V ≤ VCCB ≤ 5.5 V.
24
—
B-port supply voltage. 1.1 V ≤ VCCB ≤ 5.5 V.
—
—
Thermal pad. May be grounded (recommended) or left floating.
NAME
VCCB
PAD
(1)
DESCRIPTION
Direction-control signal for all ports. Referenced to VCCA.
Output Enable. Pull to GND to enable all outputs. Pull to VCCA to place all outputs in
high-impedance mode. Referenced to VCCA.
I = input, O = output
Submit Document Feedback
Copyright © 2023 Texas Instruments Incorporated
Product Folder Links: SN74LXC8T245-Q1
3
SN74LXC8T245-Q1
www.ti.com
SCES920B – SEPTEMBER 2020 – REVISED MARCH 2023
6 Specifications
6.1 Absolute Maximum Ratings
over operating free-air temperature range (unless otherwise noted)(1)
MIN
MAX UNIT
VCCA
Supply voltage A
–0.5
6.5
V
VCCB
Supply voltage B
–0.5
6.5
V
I/O Ports (A Port)
–0.5
6.5
VI
Input Voltage(2)
I/O Ports (B Port)
–0.5
6.5
Control Inputs
–0.5
6.5
A Port
–0.5
6.5
B Port
–0.5
6.5
A Port
–0.5 VCCA + 0.5
B Port
–0.5 VCCB + 0.5
VO
Voltage applied to any output in the high-impedance or power-off
state(2)
VO
Voltage applied to any output in the high or low state(2) (3)
IIK
Input clamp current
VI < 0
–50
IOK
Output clamp current
VO < 0
–50
IO
Continuous output current
Continuous current through VCC or GND
Tj
Junction Temperature
Tstg
Storage temperature
(1)
(2)
(3)
V
V
V
mA
mA
–50
50
mA
–200
200
mA
150
°C
150
°C
–65
Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress
ratings only, which do not imply functional operation of the device at these or any other conditions beyond those indicated under
Recommended Operating Conditions. Exposure beyond the limits listed in Recommended Operating Conditions may affect device
reliability.
The input voltage and output negative-voltage ratings may be exceeded if the input and output current ratings are observed.
The output positive-voltage rating may be exceeded up to 6.5 V maximum if the output current rating is observed.
6.2 ESD Ratings
VALUE
V(ESD)
(1)
4
Electrostatic discharge
Human body model (HBM), per AEC
Q100-002(1)
Charged device model (CDM), per AEC Q100-011
±4000
±1000
UNIT
V
AEC Q100-002 indicates that HBM stressing shall be in accordance with the ANSI/ESDA/JEDEC JS-001 specification.
Submit Document Feedback
Copyright © 2023 Texas Instruments Incorporated
Product Folder Links: SN74LXC8T245-Q1
SN74LXC8T245-Q1
www.ti.com
SCES920B – SEPTEMBER 2020 – REVISED MARCH 2023
6.3 Recommended Operating Conditions
over operating free-air temperature range (unless otherwise noted) (1) (2) (3)
MIN
VCCA
Supply voltage A
VCCB
Supply voltage B
IOH
1.08
High-level output current
IOL
MAX UNIT
1.08
Low-level output current
Input voltage (3)
VO
Output voltage
TA
(1)
(2)
(3)
V
5.5
V
VCCO = 1.1 V
–0.1
VCCO = 1.4 V
–4
VCCO = 1.65 V
–8
VCCO = 2.3 V
–12
VCCO = 3 V
–24
VCCO = 4.5 V
–32
VCCO = 1.1 V
0.1
VCCO = 1.4 V
4
VCCO = 1.65 V
8
VCCO = 2.3 V
12
VCCO = 3 V
24
VCCO = 4.5 V
VI
5.5
mA
mA
32
0
5.5
Active State
0
VCCO
Tri-State
0
5.5
Operating free-air temperature
–40
125
V
V
°C
VCCI is the VCC associated with the input port.
VCCO is the VCC associated with the output port.
All control inputs and data I/Os of this device have weak pulldowns so that the line is not floating when undefined external to the
device. The input leakage from these weak pulldowns is defined by the II specification indicated under Electrical Characteristics.
6.4 Thermal Information
SN74LXC8T245
THERMAL
METRIC(1)
PW (TSSOP)
RHL (VQFN)
DGS (VSSOP)
RJW (UQFN)
24 PINS
24 PINS
24 PINS
24 PINS
UNIT
RθJA
Junction-to-ambient thermal
resistance
99.6
47.4
86.2
118.4
°C/W
RθJC(top)
Junction-to-case (top) thermal
resistance
43.7
42.6
34.6
61.2
°C/W
RθJB
Junction-to-board thermal resistance
54.7
25.1
47.2
49.9
°C/W
YJT
Junction-to-top characterization
parameter
6.4
2.7
1.5
3.3
°C/W
YJB
Junction-to-board characterization
parameter
54.3
25.1
46.9
49.7
°C/W
RθJC(bottom)
Junction-to-case (bottom) thermal
resistance
n/a
14.9
n/a
n/a
°C/W
(1)
For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application
report.
Submit Document Feedback
Copyright © 2023 Texas Instruments Incorporated
Product Folder Links: SN74LXC8T245-Q1
5
SN74LXC8T245-Q1
www.ti.com
SCES920B – SEPTEMBER 2020 – REVISED MARCH 2023
6.5 Electrical Characteristics
over operating free-air temperature range (unless otherwise noted)(1) (2)
PARAMETER
Operating free-air temperature (TA)
TEST
CONDITIONS
VCCA
VCCB
25°C
MIN
Data Inputs
(Ax, Bx)
(Referenced to
VCCI)
VT+
Positivegoing inputthreshold
voltage
Control Inputs
(OE, DIR)
(Referenced to
VCCA)
Data Inputs
(Ax, Bx)
(Referenced to
VCCI)
VT-
Negativegoing inputthreshold
voltage
Control Inputs
(OE, DIR)
(Referenced to
VCCA)
Data Inputs
(Ax, Bx)
(Referenced to
VCCI)
ΔVT
Inputthreshold
hysteresis
(VT+ – VT-)
Control Inputs
(OE, DIR)
(Referenced to
VCCA)
6
TYP MAX
–40°C to 85°C
–40°C to 125°C
UNIT
MIN
TYP MAX
MIN
TYP MAX
1.1 V
1.1 V
0.44
0.88
0.44
0.88
1.4 V
1.4 V
0.60
0.98
0.60
0.98
1.65 V
1.65 V
0.76
1.13
0.76
1.13
2.3 V
2.3 V
1.08
1.56
1.08
1.56
3V
3V
1.48
1.92
1.48
1.92
4.5 V
4.5 V
2.19
2.74
2.19
2.74
5.5 V
5.5 V
2.65
3.33
2.65
3.33
1.1 V
1.1 V
0.44
0.88
0.44
0.88
1.4 V
1.4 V
0.60
0.98
0.60
0.98
1.65 V
1.65 V
0.76
1.13
0.76
1.13
2.3 V
2.3 V
1.08
1.56
1.08
1.56
3V
3V
1.48
1.92
1.48
1.92
4.5 V
4.5 V
2.19
2.74
2.19
2.74
5.5 V
5.5 V
2.65
3.33
2.65
3.33
1.1 V
1.1 V
0.17
0.48
0.17
0.48
1.4 V
1.4 V
0.28
0.59
0.28
0.59
1.65 V
1.65 V
0.35
0.69
0.35
0.69
2.3 V
2.3 V
0.56
0.97
0.56
0.97
3V
3V
0.89
1.5
0.89
1.5
4.5 V
4.5 V
1.51
1.97
1.51
1.97
5.5 V
5.5 V
1.88
2.4
1.88
2.4
1.1 V
1.1 V
0.17
0.48
0.17
0.48
1.4 V
1.4 V
0.28
0.6
0.28
0.6
1.65 V
1.65 V
0.35
0.71
0.35
0.71
2.3 V
2.3 V
0.56
1
0.56
1
3V
3V
0.89
1.5
0.89
1.5
4.5 V
4.5 V
1.51
2
1.51
2
5.5 V
5.5 V
1.88
2.46
1.88
2.46
1.1 V
1.1 V
0.2
0.4
0.2
0.4
1.4 V
1.4 V
0.25
0.5
0.25
0.5
1.65 V
1.65 V
0.3
0.55
0.3
0.55
2.3 V
2.3 V
0.38
0.65
0.38
0.65
3V
3V
0.46
0.72
0.46
0.72
4.5 V
4.5 V
0.58
0.93
0.58
0.93
5.5 V
5.5 V
0.69
1.06
0.69
1.06
1.1 V
1.1 V
0.2
0.4
0.2
0.4
1.4 V
1.4 V
0.25
0.5
0.25
0.5
1.65 V
1.65 V
0.3
0.55
0.3
0.55
2.3 V
2.3 V
0.38
0.65
0.38
0.65
3V
3V
0.46
0.72
0.46
0.72
4.5 V
4.5 V
0.58
0.93
0.58
0.93
5.5 V
5.5 V
0.69
1.06
0.69
1.06
Submit Document Feedback
V
V
V
V
V
V
Copyright © 2023 Texas Instruments Incorporated
Product Folder Links: SN74LXC8T245-Q1
SN74LXC8T245-Q1
www.ti.com
SCES920B – SEPTEMBER 2020 – REVISED MARCH 2023
6.5 Electrical Characteristics (continued)
over operating free-air temperature range (unless otherwise noted)(1) (2)
PARAMETER
Operating free-air temperature (TA)
TEST
CONDITIONS
VCCA
VCCB
25°C
MIN
VOH
VOL
II
High-level
output
voltage (3)
Low-level
output
voltage (4)
–40°C to 85°C
TYP MAX
MIN
–40°C to 125°C
TYP MAX
MIN
VCCO
– 0.1
VCCO
– 0.1
1
1
UNIT
TYP MAX
IOH = –100 µA
1.1 V - 5.5 V
1.1 V - 5.5 V
IOH = –4 mA
1.4 V
1.4 V
IOH = –8 mA
1.65 V
1.65 V
1.2
1.2
IOH = –12 mA
2.3 V
2.3 V
1.9
1.9
IOH = –24 mA
3V
3V
2.4
2.4
IOH = –32 mA
4.5 V
4.5 V
3.8
3.8
IOL = 100 µA
1.1 V - 5.5 V
1.1 V - 5.5 V
0.1
0.1
IOL = 4 mA
1.4 V
1.4 V
0.3
0.3
IOL = 8 mA
1.65 V
1.65 V
0.45
0.45
IOL = 12 mA
2.3 V
2.3 V
0.3
0.3
IOL = 24 mA
3V
3V
0.55
0.55
IOL = 32 mA
4.5 V
4.5 V
0.55
0.55
Control inputs
(DIR, OE)
1.1 V - 5.5 V
VI = VCCA or
Input leakage GND
current
Data Inputs
(Ax, Bx)
1.1 V - 5.5 V
VI = VCCI or GND
V
1.1 V - 5.5 V
-0.1
1.5
-0.1
2
-0.1
2
µA
1.1 V - 5.5 V
–0.3
0.3
–1
1
–2
2
µA
A Port or B Port
Partial power
VI or VO = 0 V down current
5.5 V
0V
0 V - 5.5 V
–1.5
1.5
–2
2
–2.5
2.5
Ioff
0 V - 5.5 V
0V
–1.5
1.5
–2
2
–2.5
2.5
Floating (6)
0 V - 5.5 V
–1.5
1.5
–2
2
–2.5
2.5
Ioff-float
Floating
supply Partial A Port or B Port
power down VI or VO = GND
current
0 V - 5.5 V
Floating (6)
–1.5
1.5
–2
2
–2.5
2.5
IOZ
A or B Port:
Tri-state
VI = VCCI or GND
output current VO = VCCO or
1.1 V - 5.5 V
(5)
GND
OE = VT+(MAX)
1.1 V - 5.5 V
–0.3
0.3
–1
1
–2
2
ICCA
ICCB
VCCA supply
current
VCCB supply
current
1.1 V - 5.5 V
VI = VCCI or GND
0V
IO = 0
5.5 V
1.1 V - 5.5 V
0V
1
2
4
VI = GND
IO = 0
Floating (6)
2
4
8
1.1 V - 5.5 V
2
4
8
5.5 V
1
2
4
1.1 V - 5.5 V
VI = VCCI or GND
0V
IO = 0
5.5 V
VI = GND
IO = 0
ICCA +
ICCB
Combined
supply
current
5.5 V
Floating (6)
VI = VCCI or GND
1.1 V - 5.5 V
IO = 0
V
5.5 V
0V
2
–0.2
4
–0.5
–0.2
µA
µA
µA
8
–1
–0.5
µA
µA
–1
5.5 V
2
4
8
1.1 V - 5.5 V
4
8
12
µA
Submit Document Feedback
Copyright © 2023 Texas Instruments Incorporated
Product Folder Links: SN74LXC8T245-Q1
7
SN74LXC8T245-Q1
www.ti.com
SCES920B – SEPTEMBER 2020 – REVISED MARCH 2023
6.5 Electrical Characteristics (continued)
over operating free-air temperature range (unless otherwise noted)(1) (2)
PARAMETER
TEST
CONDITIONS
Operating free-air temperature (TA)
VCCA
VCCB
25°C
MIN
MIN
–40°C to 125°C
TYP MAX
MIN
UNIT
TYP MAX
Control inputs
(DIR, OE):
VI = VCCA – 0.6 V
3.0 V - 5.5 V
A port = VCCA
or GND
B Port = open
3.0 V - 5.5 V
A Port: VI = VCCA
– 0.6 V
3.0 V - 5.5 V
DIR = VCCA, B
Port = open
3.0 V - 5.5 V
50
75
ΔICCB
VCCB
additional
supply
current per
input
B Port: VI = VCCB
- 0.6 V
3.0 V - 5.5 V
DIR = GND, A
Port = open
3.0 V - 5.5 V
50
75
µA
Ci
Control Input
Capacitance
VI = 3.3 V or
GND
3.3 V
3.3 V
2.6
5
5
pF
Cio
Data I/O
Capacitance
OE = VCCA, VO =
1.65V DC +1
3.3 V
MHz -16 dBm
sine wave
3.3 V
5.8
10
10
pF
ΔICCA
(1)
(2)
(3)
(4)
(5)
(6)
8
TYP MAX
–40°C to 85°C
VCCA
additional
supply
current per
input
50
75
µA
VCCI is the VCC associated with the input port.
VCCO is the VCC associated with the output port.
Tested at VI = VT+(MAX).
Tested at VI = VT-(MIN).
For I/O ports, the parameter IOZ includes the input leakage current.
Floating is defined as a node that is both not actively driven by an external device and has leakage not exeeding 10 nA.
Submit Document Feedback
Copyright © 2023 Texas Instruments Incorporated
Product Folder Links: SN74LXC8T245-Q1
SN74LXC8T245-Q1
www.ti.com
SCES920B – SEPTEMBER 2020 – REVISED MARCH 2023
6.6 Switching Characteristics, VCCA = 1.2 ± 0.1 V
See Figure 7-1 and Table 7-1 for test circuit and loading. See Figure 7-2, Figure 7-3, and Figure 7-4 for measurement waveforms.
PARAMETER
FROM
TO
TEST
CONDITIONS
B-PORT SUPPLY VOLTAGE (VCCB)
1.2 ± 0.1 V
MIN TYP
tpd
tdis
A
B
B
A
OE
A
OE
B
Propagation
delay
Disable time
OE
ten
A
Enable time
OE
B
1.5 ± 0.1 V
MAX MIN TYP
1.8 ± 0.15 V
MAX MIN TYP
2.5 ± 0.2 V
MAX MIN TYP
3.3 ± 0.3 V
MAX MIN TYP
5.0 ± 0.5 V
MAX MIN TYP
UNIT
MAX
–40°C to 85°C
10
65
10
31
7
25
7
24
5
22
5
21
–40°C to 125°C
10
70
10
33
7
27
7
26
5
24
5
23
–40°C to 85°C
10
62
10
55
10
49
8
42
8
40
8
39
–40°C to 125°C
10
68
10
60
10
54
8
47
8
45
8
44
–40°C to 85°C
20
64
20
64
20
64
20
64
20
64
20
64
–40°C to 125°C
20
69
20
69
20
69
20
69
20
69
20
69
–40°C to 85°C
20
80
20
62
20
54
20
48
20
47
20
45
–40°C to 125°C
20
85
20
67
20
59
20
52
20
50
20
48
–40°C to 85°C
20
90
20
91
20
91
20
91
20
90
20
90
–40°C to 125°C
20
97
20
98
20
97
20
96
20
96
20
96
–40°C to 85°C
20
95
20
57
15
48
10
38
10
36
10
36
–40°C to 125°C
20
100
20
61
15
53
10
42
10
39
10
39
Submit Document Feedback
Copyright © 2023 Texas Instruments Incorporated
Product Folder Links: SN74LXC8T245-Q1
ns
ns
ns
9
SN74LXC8T245-Q1
www.ti.com
SCES920B – SEPTEMBER 2020 – REVISED MARCH 2023
6.7 Switching Characteristics, VCCA = 1.5 ± 0.1 V
See Figure 7-1 and Table 7-1 for test circuit and loading. See Figure 7-2, Figure 7-3, and Figure 7-4 for measurement waveforms.
PARAMETER
FROM
TO
TEST
CONDITIONS
B–PORT SUPPLY VOLTAGE (VCCB)
1.2 ± 0.1 V
MIN TYP
tpd
tdis
A
B
B
A
OE
A
OE
B
Propagation
delay
Disable time
OE
ten
Enable time
OE
10
A
B
1.5 ± 0.1 V
MAX MIN TYP
1.8 ± 0.15 V
MAX MIN TYP
2.5 ± 0.2 V
MAX MIN TYP
3.3 ± 0.3 V
MAX MIN TYP
5.0 ± 0.5 V
MAX MIN TYP
UNIT
MAX
–40°C to 85°C
10
52
5
25
5
23
5
17
5
14
3
13
–40°C to 125°C
10
57
5
26
5
23
5
18
5
16
3
14
–40°C to 85°C
8
36
7
28
7
26
5
20
5
18
5
17
–40°C to 125°C
8
40
7
29
7
26
5
22
5
20
5
18
–40°C to 85°C
15
40
15
40
15
40
15
40
15
40
15
40
–40°C to 125°C
15
44
15
44
15
44
15
44
15
44
15
44
–40°C to 85°C
20
69
20
50
15
45
15
35
15
34
14
31
–40°C to 125°C
20
74
20
54
15
48
15
39
15
37
14
33
–40°C to 85°C
15
48
15
48
15
48
15
48
15
48
15
48
–40°C to 125°C
15
52
15
52
15
52
15
52
15
52
15
52
–40°C to 85°C
20
85
15
50
15
40
10
31
10
26
10
24
–40°C to 125°C
20
91
15
54
15
44
10
33
10
29
10
26
Submit Document Feedback
ns
ns
ns
Copyright © 2023 Texas Instruments Incorporated
Product Folder Links: SN74LXC8T245-Q1
SN74LXC8T245-Q1
www.ti.com
SCES920B – SEPTEMBER 2020 – REVISED MARCH 2023
6.8 Switching Characteristics, VCCA = 1.8 ± 0.15 V
See Figure 7-1 and Table 7-1 for test circuit and loading. See Figure 7-2, Figure 7-3, and Figure 7-4 for measurement waveforms.
PARAMETER
FROM
TO
TEST
CONDITIONS
B–PORT SUPPLY VOLTAGE (VCCB)
1.2 ± 0.1 V
MIN TYP
tpd
tdis
A
B
B
A
OE
A
OE
B
Propagation
delay
Disable time
OE
ten
A
Enable time
OE
B
1.5 ± 0.1 V
MAX MIN TYP
1.8 ± 0.15 V
MAX MIN TYP
2.5 ± 0.2 V
MAX MIN TYP
3.3 ± 0.3 V
MAX MIN TYP
5.0 ± 0.5 V
MAX MIN TYP
UNIT
MAX
–40°C to 85°C
8
50
6
21
6
18
4
14
4
11
2
10
–40°C to 125°C
8
53
6
23
6
20
4
15
4
12
2
11
–40°C to 85°C
5
32
5
21
5
19
4
17
4
15
4
15
–40°C to 125°C
5
33
5
23
5
21
4
18
4
16
4
16
–40°C to 85°C
10
34
10
33
10
33
10
33
10
33
10
33
–40°C to 125°C
10
36
10
35
10
35
10
35
10
35
10
35
–40°C to 85°C
20
64
15
45
15
40
12
31
12
31
10
26
–40°C to 125°C
20
69
15
49
15
44
12
33
12
38
10
28
–40°C to 85°C
10
38
10
38
10
38
10
38
10
38
10
38
–40°C to 125°C
10
40
10
40
10
40
10
40
10
40
10
40
–40°C to 85°C
20
84
15
47
10
38
10
29
10
25
8
23
–40°C to 125°C
20
89
15
51
10
42
10
30
10
26
8
25
Submit Document Feedback
Copyright © 2023 Texas Instruments Incorporated
Product Folder Links: SN74LXC8T245-Q1
ns
ns
ns
11
SN74LXC8T245-Q1
www.ti.com
SCES920B – SEPTEMBER 2020 – REVISED MARCH 2023
6.9 Switching Characteristics, VCCA = 2.5 ± 0.2 V
See Figure 7-1 and Table 7-1 for test circuit and loading. See Figure 7-2, Figure 7-3, and Figure 7-4 for measurement waveforms.
PARAMETER
FROM
TO
TEST
CONDITIONS
B–PORT SUPPLY VOLTAGEe (VCCB)
1.2 ± 0.1 V
MIN TYP
tpd
tdis
A
B
B
A
OE
A
OE
B
Propagation
delay
Disable time
OE
ten
Enable time
OE
12
A
B
1.5 ± 0.1 V
MAX MIN TYP
1.8 ± 0.15 V
MAX MIN TYP
2.5 ± 0.2 V
MAX MIN TYP
3.3 ± 0.3 V
MAX MIN TYP
5.0 ± 0.5 V
MAX MIN TYP
UNIT
MAX
–40°C to 85°C
7
40
5
21
4
16
3
12
3
10
3
8
–40°C to 125°C
7
45
5
22
4
17
3
13
3
11
3
9
–40°C to 85°C
5
26
5
16
5
15
4
12
3
11
3
10
–40°C to 125°C
5
28
5
17
5
15
4
13
3
12
3
11
–40°C to 85°C
10
24
10
24
10
24
10
24
10
22
10
24
–40°C to 125°C
10
26
10
26
10
24
10
24
10
24
10
24
–40°C to 85°C
15
56
15
41
12
34
12
25
10
24
10
21
–40°C to 125°C
15
62
15
44
12
37
12
29
10
26
10
22
–40°C to 85°C
8
25
8
25
8
25
8
25
8
25
8
25
–40°C to 125°C
8
27
8
27
8
27
8
27
8
27
8
27
–40°C to 85°C
20
80
15
46
10
34
10
25
5
23
5
18
–40°C to 125°C
20
86
15
48
10
37
10
27
5
25
5
20
Submit Document Feedback
ns
ns
ns
Copyright © 2023 Texas Instruments Incorporated
Product Folder Links: SN74LXC8T245-Q1
SN74LXC8T245-Q1
www.ti.com
SCES920B – SEPTEMBER 2020 – REVISED MARCH 2023
6.10 Switching Characteristics, VCCA = 3.3 ± 0.3 V
See Figure 7-1 and Table 7-1 for test circuit and loading. See Figure 7-2, Figure 7-3, and Figure 7-4 for measurement waveforms.
PARAMETER
FROM
TO
TEST
CONDITIONS
B–PORT SUPPLY VOLTAGE (VCCB)
1.2 ± 0.1 V
MIN TYP
tpd
tdis
A
B
B
A
OE
A
OE
B
Propagation
delay
Disable time
OE
ten
A
Enable time
OE
B
1.5 ± 0.1 V
MAX MIN TYP
1.8 ± 0.15 V
MAX MIN TYP
2.5 ± 0.2 V
MAX MIN TYP
3.3 ± 0.3 V
MAX MIN TYP
5.0 ± 0.5 V
MAX MIN TYP
UNIT
MAX
–40°C to 85°C
8
41
6
19
4
15
3
10
3
9
2
6.5
–40°C to 125°C
8
43
6
21
4
16
3
11
3
10
2
7.5
–40°C to 85°C
5
22
5
15
4
12
3
10
3
9
3
8.5
–40°C to 125°C
5
24
5
16
4
13
3
11
3
10
3
9
–40°C to 85°C
9
19
9
19
9
19
8
19
8
19
8
19
–40°C to 125°C
9
20
9
20
9
20
8
20
8
20
8
20
–40°C to 85°C
15
52
15
38
12
32
10
23
10
22
9
18
–40°C to 125°C
15
59
15
41
12
35
10
26
10
23
9
20
–40°C to 85°C
5
20
5
20
5
20
5
20
5
20
5
20
–40°C to 125°C
5
22
5
22
5
22
5
22
5
22
5
22
–40°C to 85°C
20
80
15
43
10
34
5
24
5
19
5
16
–40°C to 125°C
20
85
15
46
10
36
5
27
5
21
5
18
Submit Document Feedback
Copyright © 2023 Texas Instruments Incorporated
Product Folder Links: SN74LXC8T245-Q1
ns
ns
ns
13
SN74LXC8T245-Q1
www.ti.com
SCES920B – SEPTEMBER 2020 – REVISED MARCH 2023
6.11 Switching Characteristics, VCCA = 5.0 ± 0.5 V
See Figure 7-1 and Table 7-1 for test circuit and loading. See Figure 7-2, Figure 7-3, and Figure 7-4 for measurement waveforms.
PARAMETER
FROM
TO
TEST
CONDITIONS
B–PORT SUPPLY VOLTAGE (VCCB)
1.2 ± 0.1 V
MIN TYP
tpd
tdis
A
B
B
A
OE
A
OE
B
Propagation
delay
Disable time
OE
ten
Enable time
OE
14
A
B
1.5 ± 0.1 V
MAX MIN TYP
1.8 ± 0.15 V
MAX MIN TYP
2.5 ± 0.2 V
MAX MIN TYP
3.3 ± 0.3 V
MAX MIN TYP
5.0 ± 0.5 V
MAX MIN TYP
UNIT
MAX
–40°C to 85°C
8
38
6
15
3
14
3
9.5
2
8
2
6
–40°C to 125°C
8
42
6
17
3
15
3
10.5
2
8.5
2
7
–40°C to 85°C
5
22
4
13
3
10.5
3
8
2
7.5
2
7
–40°C to 125°C
5
24
4
15
3
11.5
3
8.5
2
8
2
7.5
–40°C to 85°C
7
15
5
15
5
15
5
15
5
14
5
14
–40°C to 125°C
7
16
5
16
5
16
5
16
5
15
5
15
–40°C to 85°C
15
52
12
33
10
31
10
22
10
21
5
16
–40°C to 125°C
15
56
12
37
10
35
10
24
10
23
5
18
–40°C to 85°C
5
15
5
15
5
15
5
15
5
15
5
15
–40°C to 125°C
5
16
5
16
5
16
5
16
5
16
5
16
–40°C to 85°C
20
80
15
44
10
33
5
24
5
18
5
15
–40°C to 125°C
20
85
15
48
10
35
5
26
5
20
5
17
Submit Document Feedback
ns
ns
ns
Copyright © 2023 Texas Instruments Incorporated
Product Folder Links: SN74LXC8T245-Q1
SN74LXC8T245-Q1
www.ti.com
SCES920B – SEPTEMBER 2020 – REVISED MARCH 2023
6.12 Switching Characteristics: Tsk, TMAX
over operating free-air temperature range (unless otherwise noted)
Operating temp (TA)
PARAMETER
TEST CONDITIONS
VCCI
Up Translation
50% Duty Cycle Input
TMAX - Maximum One channel switching
Data Rate
20% of pulse > 0.7*VCCO
20% of pulse < 0.3*VCCO
Down Translation
Up Translation
tsk - Output skew
Timing skew between
any two switching
outputs within the same
device
Down Translation
VCCO
-40°C to 125°C
MIN
TYP
3.0 V – 3.6 V
4.5 V – 5.5 V
200
420
1.65 V – 1.95 V
4.5 V – 5.5 V
100
200
1.1 V – 1.3 V
4.5 V – 5.5 V
20
40
1.65 V – 1.95 V
3.0 V – 3.6 V
100
210
1.1 V – 1.3 V
3.0 V – 3.6 V
10
20
1.1 V – 1.3 V
1.65 V – 1.95 V
4.5 V – 5.5 V
3.0 V – 3.6 V
4.5 V – 5.5 V
4.5 V – 5.5 V
UNIT
MAX
5
10
100
210
1.65 V – 1.95 V
50
75
1.1 V – 1.3 V
15
30
3.0 V – 3.6 V
1.65 V – 1.95 V
40
75
3.0 V – 3.6 V
1.1 V – 1.3 V
10
20
1.65 V – 1.95 V
1.1 V – 1.3 V
5
10
3.0 V – 3.6 V
4.5 V – 5.5 V
1.65 V – 1.95 V
4.5 V – 5.5 V
1
1.1 V – 1.3 V
4.5 V – 5.5 V
1.5
1.65 V – 1.95 V
3.0 V – 3.6 V
1
1.1 V – 1.3 V
3.0 V – 3.6 V
1.5
1.1 V – 1.3 V
1.65 V – 1.95 V
4.5 V – 5.5 V
3.0 V – 3.6 V
4.5 V – 5.5 V
1.65 V – 1.95 V
4.5 V – 5.5 V
1.1 V – 1.3 V
3.0 V – 3.6 V
1.65 V – 1.95 V
3.0 V – 3.6 V
1.1 V – 1.3 V
1.5
1.65 V – 1.95 V
1.1 V – 1.3 V
2
Mbps
0.5
2
0.5
ns
1
1.5
1
6.13 Operating Characteristics
TA = 25℃ (1)
Supply Voltage (VCCB = VCCA)
PARAMETER
A to B: outputs enabled
CpdA (2)
A to B: outputs disabled
B to A: outputs enabled
B to A: outputs disabled
A to B: outputs enabled
CpdB
(2)
A to B: outputs disabled
B to A: outputs enabled
B to A: outputs disabled
(1)
(2)
Test Conditions
A Port
CL = 0, RL = Open
f = 10 MHz
trise = tfall = 1 ns
B Port
CL = 0, RL = Open
f = 10 MHz
trise = tfall = 1 ns
1.2 ± 0.1V 1.5 ± 0.1V
1.8 ± 0.15V
2.5 ± 0.2V 3.3 ± 0.3V 5.0 ± 0.5V
TYP
TYP
TYP
TYP
TYP
TYP
2
2
2
2
2
3
2
2
2
2
2
3
12
12
12
13
13
16
2
2
2
2
2
3
12
12
12
13
13
16
2
2
2
2
2
3
2
2
2
2
2
3
2
2
2
2
2
3
UNIT
pF
pF
For more information about power dissipation capacitance, see the CMOS Power Consumption and Cpd Calculation application report.
CpdA and CpdB are repectively A-Port and B-Port power dissipation capacitances per transceiver.
Submit Document Feedback
Copyright © 2023 Texas Instruments Incorporated
Product Folder Links: SN74LXC8T245-Q1
15
SN74LXC8T245-Q1
www.ti.com
SCES920B – SEPTEMBER 2020 – REVISED MARCH 2023
6.14 Typical Characteristics
4.5
1.6
4
VOH
Output High Voltage (V)
1.8
VOH
Output High Voltage (V)
5
1.4
VCC = 5 V
VCC = 3.3 V
VCC = 2.5 V
3.5
1.2
3
2.5
1
0.8
2
VCC = 1.8 V
VCC = 1.5 V
VCC = 1.2 V
0.6
1.5
0.4
0
5
10
15
20
25
30
35
40
IOH Output High Current (mA)
45
50
Figure 6-1. Typical (TA=25°C) Output High Voltage (VOH) vs
Source Current (IOH)
0
0.35
0.35
VOL
Output Low Voltage (V)
0.4
VOL
Output Low Voltage (V)
0.45
0.4
0.3
5
7.5 10 12.5 15 17.5 20
IOH Output High Current (mA)
22.5
25
Figure 6-2. Typical (TA=25°C) Output High Voltage (VOH) vs
Source Current (IOH)
0.45
0.25
2.5
0.3
0.25
0.2
0.15
0.2
0.15
0.1
VCC = 5 V
VCC = 3.3 V
VCC = 2.5 V
0.05
0
0
5
10
15
20
25
30
35
40
IOL Output Low Current (mA)
45
0.1
VCC = 1.8 V
VCC = 1.5 V
VCC = 1.2 V
0.05
0
50
Figure 6-3. Typical (TA=25°C) Output Low Voltage (VOL) vs Sink
Current (IOL)
0
2.5
5
7.5 10 12.5 15 17.5 20
IOL Output Low Current (mA)
22.5
25
Figure 6-4. Typical (TA=25°C) Output Low Voltage (VOL) vs Sink
Current (IOL)
2
1.6
0.18
1.4
0.16
1.2
0.14
0.12
1
0.8
0.1
0.08
0.6
0.06
0.4
0.04
0.2
0.02
0
0
0.5
1
1.5
2
2.5
3
3.5
VIN Input Voltage (V)
4
4.5
5
Figure 6-5. Typical (TA=25°C) Supply Current (ICC) vs Input
Voltage (VIN)
16
VCC = 1.8 V
VCC = 1.5 V
VCC = 1.2 V
0.2
ICC
Supply Current (mA)
Supply Current (mA)
ICC
0.22
VCC = 5 V
VCC = 3.3 V
VCC = 2.5 V
1.8
0
0
0.2
0.4
0.6
0.8
1
1.2
VIN Input Voltage (V)
1.4
1.6
1.8
Figure 6-6. Typical (TA=25°C) Supply Current (ICC) vs Input
Voltage (VIN)
Submit Document Feedback
Copyright © 2023 Texas Instruments Incorporated
Product Folder Links: SN74LXC8T245-Q1
SN74LXC8T245-Q1
www.ti.com
SCES920B – SEPTEMBER 2020 – REVISED MARCH 2023
7 Parameter Measurement Information
7.1 Load Circuit and Voltage Waveforms
Unless otherwise noted, all input pulses are supplied by generators having the following characteristics:
• f = 1 MHz
• ZO = 50 Ω
• Δt/ΔV ≤ 1 ns/V
Measurement Point
2 x VCCO
RL
S1
Output Pin
Under Test
Open
CL(1)
1.
GND
RL
CL includes probe and jig capacitance.
Figure 7-1. Load Circuit
Table 7-1. Load Circuit Conditions
Parameter
tpd
Propagation (delay) time
ten, tdis Enable time, disable time
ten, tdis Enable time, disable time
VCCO
RL
CL
S1
1.1 V – 5.5 V
2 kΩ
15 pF
Open
N/A
1.1 V – 1.6 V
2 kΩ
15 pF
2 × VCCO
0.1 V
1.65 V – 2.7 V
2 kΩ
15 pF
2 × VCCO
0.15 V
3.0 V – 5.5 V
2 kΩ
15 pF
2 × VCCO
0.3 V
1.1 V – 1.6 V
2 kΩ
15 pF
GND
0.1 V
1.65 V – 2.7 V
2 kΩ
15 pF
GND
0.15 V
3.0 V – 5.5 V
2 kΩ
15 pF
GND
0.3 V
VCCI(1)
VCCI(1)
Input A, B
Input A, B
VCCI / 2
VCCI / 2
100 kHz
500 ps/V ± 1 s/V
0V
0V
tpd
VOH(2)
tpd
VOH(2)
Output B, A
VCCI / 2
Output B, A
Ensure Monotonic
Rising and Falling Edge
VOL(2)
VCCI / 2
VOL(2)
1.
2.
VTP
VCCI is the supply pin associated with the input port.
VOH and VOL are typical output voltage levels that occur
with specified RL, CL, and S1
1.
2.
VCCI is the supply pin associated with the input port.
VOH and VOL are typical output voltage levels that occur
with specified RL, CL, and S1
Figure 7-3. Input Transition Rise and Fall Rate
Figure 7-2. Propagation Delay
Submit Document Feedback
Copyright © 2023 Texas Instruments Incorporated
Product Folder Links: SN74LXC8T245-Q1
17
SN74LXC8T245-Q1
www.ti.com
SCES920B – SEPTEMBER 2020 – REVISED MARCH 2023
VCCA
OE
VCCA / 2
VCCA / 2
GND
tdis
ten
VCCO(3)
Output(1)
VCCO / 2
VOL + VTP
VOL(4)
VOH(4)
VOH - VTP
Output(2)
VCCO / 2
GND
1.
2.
3.
4.
Output waveform on the condition that input is driven to a valid Logic Low.
Output waveform on the condition that input is driven to a valid Logic High.
VCCO is the supply pin associated with the output port.
VOH and VOL are typical output voltage levels with specified RL, CL, and S1.
Figure 7-4. Enable Time And Disable Time
18
Submit Document Feedback
Copyright © 2023 Texas Instruments Incorporated
Product Folder Links: SN74LXC8T245-Q1
SN74LXC8T245-Q1
www.ti.com
SCES920B – SEPTEMBER 2020 – REVISED MARCH 2023
8 Detailed Description
8.1 Overview
The SN74LXC8T245-Q1 is an 8-bit translating transceiver that uses two individually configurable power-supply
rails. The device is operational with both VCCA and VCCB supplies as low as 1.1 V and as high as 5.5 V.
Additionally, the device can operate with VCCA = VCCB. The A port is designed to track VCCA, and the B port is
designed to track VCCB.
The SN74LXC8T245-Q1 device is designed for asynchronous communication between data buses, and
transmits data from the A bus to the B bus or from the B bus to the A bus based on the logic level of the
direction-control input (DIR). The output-enable input (OE) is used to disable the outputs so the buses are
effectively isolated. The control pins of the SN74LXC8T245-Q1 (DIR and OE) are referenced to VCCA. For the
level shifter I/Os to be in the high-impedance state during power up or power down, the OE pin should be tied to
VCCA through a pullup resistor.
This device is fully specified for partial-power-down applications using the Ioff current. The Ioff protection circuitry
is designed so that no excessive current is drawn from or sourced into an input, output, or I/O while the device is
powered down.
The VCC isolation or VCC disconnect feature is designed so that if either VCC is less than 100 mV or
disconnected with the complementary supply within recommended operating conditions, both I/O ports are
weakly pulled-down and then set to the high-impedance state by disabling their outputs while the supply current
is maintained. The Ioff-float circuitry is designed so that no excessive current is drawn from or sourced into an
input, output, or I/O while the supply is floating.
Glitch-free power supply sequencing allows either supply rail to be powered on or off in any order while providing
robust power sequencing performance.
8.2 Functional Block Diagram
VCCB
VCCA
DIR
OE
B1
A1
A8
To other 7 channels
B8
GND
Submit Document Feedback
Copyright © 2023 Texas Instruments Incorporated
Product Folder Links: SN74LXC8T245-Q1
19
SN74LXC8T245-Q1
SCES920B – SEPTEMBER 2020 – REVISED MARCH 2023
www.ti.com
8.3 Feature Description
8.3.1 CMOS Schmitt-Trigger Inputs with Integrated Pulldowns
Standard CMOS inputs are high impedance and are typically modeled as a resistor in parallel with the input
capacitance given in the Electrical Characteristics. The worst case resistance is calculated with the maximum
input voltage, given in the Absolute Maximum Ratings, and the maximum input leakage current, given in the
Electrical Characteristics, using ohm's law (R = V ÷ I).
The Schmitt-trigger input architecture provides hysteresis as defined by ΔVT in the Electrical Characteristics,
which makes this device extremely tolerant to slow or noisy inputs. Driving the inputs slowly will increase
dynamic current consumption of the device. For additional information regarding Schmitt-trigger inputs, see the
Understanding Schmitt Triggers application brief.
8.3.1.1 I/Os with Integrated Dynamic Pull-Down Resistors
Input circuits of the data I/Os are always active even when the device is disabled. It is recommended to keep a
valid voltage level at the I/Os to avoid high current consumption. To help avoid floating inputs on the I/Os during
disabling, this device has 100-kΩ typical integrated weak dynamic pull-downs on all data I/Os. When the device
is disabled, the dynamic pull-downs are activated for only a short period of time to help drive and keep low any
floating inputs before the device I/Os become high impedance. If the I/O lines will be floated after the device
is disabled, then it is recommended to keep them at a valid input voltage level using external pull-downs. This
feature is ideal for loads of 30 pF or less. If greater capactive loading is present, then external pull-downs are
recommended. If an external pull-up is required, then it should be no larger than 15 kΩ to avoid contention with
the 100 kΩ internal pull-down.
8.3.1.2 Control Inputs with Integrated Static Pull-Down Resistors
Similar to the data I/Os, floating control inputs can cause high current consumption. This device has integrated
weak static pull-downs of 5-MΩ typical on the control inputs (DIR and OE) to help avoid this concern. These
pull-downs are always present. For example, if the DIR pin is left floating, then the B port will be configured as an
input and the A port will be configured as an output.
8.3.2 Balanced High-Drive CMOS Push-Pull Outputs
A balanced output allows the device to sink and source similar currents. The high drive capability of this device
creates fast edges into light loads so routing and load conditions should be considered to prevent ringing.
Additionally, the outputs of this device are capable of driving larger currents than the device can sustain without
being damaged. The electrical and thermal limits defined in the Absolute Maximum Ratings must be followed at
all times.
8.3.3 Partial Power Down (Ioff)
The inputs and outputs for this device enter a high-impedance state when the device is powered down, inhibiting
current backflow into the device. The maximum leakage into or out of any input or output pin on the device is
specified by Ioff in the Electrical Characteristics.
20
Submit Document Feedback
Copyright © 2023 Texas Instruments Incorporated
Product Folder Links: SN74LXC8T245-Q1
SN74LXC8T245-Q1
www.ti.com
SCES920B – SEPTEMBER 2020 – REVISED MARCH 2023
8.3.4 VCC Isolation and VCC Disconnect (Ioff-float)
This device has I/Os with Integrated Dynamic Pull-Down Resistors. The I/Os will get pulled down and then enter
a high-impedance state when either supply is < 100 mV or left floating (disconnected), while the other supply is
still connected to the device. It is recommended that the I/Os for this device are not driven and kept at a logic low
state prior to floating (disconnecting) either supply.
The maximum supply current is specified by ICCx, while VCCx is floating, in the Electrical Characterstics. The
maximum leakage into or out of any input or output pin on the device is specified by Ioff(float) in the Electrical
Characteristics.
VCCA
VCCB
ICCB maintained
Supply disconnected
VCCA
VCCB
DIR
OE
Disabled
Hi-Z
A1
Ioff(float)
Hi-Z
B1
Ioff(float)
Disabled
GND
Figure 8-1. VCC Disconnect Feature
8.3.5 Over-Voltage Tolerant Inputs
Input signals to this device can be driven above the supply voltage so long as they remain below the maximum
input voltage value specified in the Recommended Operating Conditions.
8.3.6 Glitch-Free Power Supply Sequencing
Either supply rail may be powered on or off in any order without producing a glitch on the I/Os (that is, where
the output erroneously transitions to VCC when it should be held low or vice versa). Glitches of this nature can
be misinterpreted by a peripheral as a valid data bit, which could trigger a false device reset of the peripheral, a
false device configuration of the peripheral, or even a false data initialization by the peripheral.
Submit Document Feedback
Copyright © 2023 Texas Instruments Incorporated
Product Folder Links: SN74LXC8T245-Q1
21
SN74LXC8T245-Q1
www.ti.com
SCES920B – SEPTEMBER 2020 – REVISED MARCH 2023
8.3.7 Negative Clamping Diodes
Figure 8-2 shows how the inputs and outputs to this device have negative clamping diodes.
CAUTION
Voltages beyond the values specified in the Absolute Maximum Ratings table can cause damage to
the device. The input negative-voltage and output voltage ratings may be exceeded if the input and
output clamp-current ratings are observed.
VCCA
VCCB
Device
Input or I/O
configured
as input
Level
Shifter
I/O configured
as output
-IIK
-IOK
GND
Figure 8-2. Electrical Placement of Clamping Diodes for Each Input and Output
8.3.8 Fully Configurable Dual-Rail Design
Both the VCCA and VCCB pins can be supplied at any voltage from 1.1 V to 5.5 V, making the device suitable for
translating between any of the voltage nodes (1.2 V, 1.5 V, 1.8 V, 3.3 V, and 5.0 V).
8.3.9 Supports High-Speed Translation
The SN74LXC8T245-Q1 device can support high data-rate applications. The translated signal data rate can be
up to 420 Mbps when the signal is translated from 3.3 V to 5.0 V.
8.4 Device Functional Modes
Table 8-1. Function Table
CONTROL INPUTS (1)
OE
(1)
22
PORT STATUS
B PORT
OPERATION
DIR
A PORT
L
L
Output (Enabled)
Input (Hi-Z)
B data to A bus
L
H
Input (Hi-Z)
Output (Enabled)
A data to B bus
H
X
Input (Hi-Z)
Input (Hi-Z)
Isolation
Input circuits of the data I/Os are always active and should be kept at a valid logic level.
Submit Document Feedback
Copyright © 2023 Texas Instruments Incorporated
Product Folder Links: SN74LXC8T245-Q1
SN74LXC8T245-Q1
www.ti.com
SCES920B – SEPTEMBER 2020 – REVISED MARCH 2023
9 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.
9.1 Application Information
The SN74LXC8T245-Q1 device can be used in level-translation applications for interfacing devices or systems
operating at different interface voltages with one another. The SN74LXC8T245-Q1 device is ideal for use in
applications where a push-pull driver is connected to the data I/Os. The maximum data rate can be up to 420
Mbps when device translates a signal from 3.3 V to 5.0 V.
9.2 Typical Application
VCCA
VCCB
GPIO0
PWM0
GPIO1
PWM1
GPIO7
PWM7
Controller
LED Array,
FET Array,
Buzzer,
MCU,
Etc...
1010
SN74LXC8T245
Figure 9-1. LED Driver Application
9.2.1 Design Requirements
For this design example, use the parameters listed in Table 9-1.
Table 9-1. Design Parameters
DESIGN PARAMETERS
EXAMPLE VALUES
Input voltage range
1.1 V to 5.5 V
Output voltage range
1.1 V to 5.5 V
9.2.2 Detailed Design Procedure
To begin the design process, determine the following:
• Input voltage range
– Use the supply voltage of the device that is driving the SN74LXC8T245-Q1 device to determine the input
voltage range. For a valid logic-high, the value must exceed the positive-going input-threshold voltage
(Vt+) of the input port. For a valid logic low the value must be less than the negative-going input-threshold
voltage (Vt-) of the input port.
• Output voltage range
– Use the supply voltage of the device that the SN74LXC8T245-Q1 device is driving to determine the output
voltage range.
Submit Document Feedback
Copyright © 2023 Texas Instruments Incorporated
Product Folder Links: SN74LXC8T245-Q1
23
SN74LXC8T245-Q1
www.ti.com
SCES920B – SEPTEMBER 2020 – REVISED MARCH 2023
9.3 Power Supply Recommendations
Always apply a ground reference to the GND pins first. This device is designed for glitch free power sequencing
without any supply sequencing requirements such as ramp order or ramp rate.
This device was designed with various power supply sequencing methods in mind to help prevent unintended
triggering of downstream devices, as described in Glitch-free Power Supply Sequencing.
9.4 Layout
9.4.1 Layout Guidelines
For device reliability, following common printed-circuit board layout guidelines are recommended:
• Use bypass capacitors on the power supply pins and place them as close to the device as possible. A 0.1-µF
capacitor is recommended, but transient performance can be improved by having both 1-µF and 0.1-µF
capacitors in parallel as bypass capacitors.
• The high drive capability of this device creates fast edges into light loads, so routing and load conditions
should be considered to prevent ringing.
9.4.2 Layout Example
Via to VCCA
Via to VCCB
Legend
A
G
Via to GND
Copper Traces
B
SN74LXC8T245QPWRQ1
VCCA
G
020 1
0.1µF
1
VCCB
24
A
B
020 1
0.1µF
DIR
2
23
VCCB
A1
3
22
OE
A2
4
21
B1
A3
5
20
B2
A4
6
19
B3
A5
7
18
B4
A6
8
17
B5
A7
9
16
B6
A8
10
15
B7
GND
11
14
B8
12
13
GND
From
Controller
G
G
G
To LED
Array
G
GND
G
Figure 9-2. Layout Example – SN74LXC8T245PW-Q1
24
Submit Document Feedback
Copyright © 2023 Texas Instruments Incorporated
Product Folder Links: SN74LXC8T245-Q1
SN74LXC8T245-Q1
www.ti.com
SCES920B – SEPTEMBER 2020 – REVISED MARCH 2023
10 Device and Documentation Support
10.1 Documentation Support
10.1.1 Related Documentation
For related documentation, see the following:
• Texas Instruments, Understanding Schmitt Triggers application report
10.2 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.
10.3 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.
10.4 Trademarks
TI E2E™ is a trademark of Texas Instruments.
All trademarks are the property of their respective owners.
10.5 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.
10.6 Glossary
TI Glossary
This glossary lists and explains terms, acronyms, and definitions.
11 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 © 2023 Texas Instruments Incorporated
Product Folder Links: SN74LXC8T245-Q1
25
PACKAGE OPTION ADDENDUM
www.ti.com
15-Apr-2023
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)
CLXC8T245QDGSRQ1
ACTIVE
VSSOP
DGS
24
5000
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 125
L8245Q
Samples
CLXC8T245QRHLRQ1
ACTIVE
VQFN
RHL
24
3000
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 125
LX8T245Q
Samples
SN74LXC8T245QPWRQ1
ACTIVE
TSSOP
PW
24
2000
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 125
LX8T245Q
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
工商网监
湘ICP备2023018690号
