Specifications
| Type | Description |
|---|---|
| Part Number | TCA9543 |
| Manufacturer | Texas Instruments |
| Product Type | I2C Switch |
| Category | Signal Chain |
| Package / Case | TSSOP-14 (PW) 5.00 mm x 4.40 mm; SOIC-14 (D) 8.65 mm x 3.91 mm |
| I2C Channel Count | 2 downstream channel pairs; SCL/SDA upstream pair fans out to SC0/SD0 and SC1/SD1 |
| Switch Configuration | 1-of-2 bidirectional translating switches; channels selectable via I2C bus in any combination |
| Supply Voltage | 1.65-5.5 V recommended operating condition |
| Maximum I2C Clock Frequency | 400 kHz fast-mode I2C bus |
| Supported Bus Voltages | 1.8 V, 2.5 V, 3.3 V, 5 V for voltage-level translation between buses |
| Input Tolerance | 5.5 V tolerant inputs on all I/O terminals |
| Power-Up Default State | All switch channels deselected at power-up or reset |
| Address Pins | 2 pins; A0 and A1 allow up to four devices on I2C bus |
| Interrupt Inputs | 2 active-low inputs; INT0 and INT1, one per downstream channel |
| Interrupt Output | 1 active-low output; INT acts as AND of interrupt inputs |
| Reset Input | Active-low RESET; resets I2C state machine and deselects both channels |
| Absolute Maximum Supply Voltage | -0.5 to 7 V over operating free-air temperature range |
| Absolute Maximum Input Voltage | -0.5 to 7 V; input negative-voltage rating may be exceeded if input current rating is observed |
| Absolute Maximum Input Current | ±20 mA, any input |
| Absolute Maximum Output Current | ±25 mA, any output |
| Continuous Current Through VCC | ±100 mA absolute maximum rating |
| Continuous Current Through GND | ±100 mA absolute maximum rating |
| Total Power Dissipation | 400 mW absolute maximum rating |
| Operating Free-Air Temperature | -40 to 85 °C recommended operating condition and absolute maximum operating range |
| Storage Temperature | -60 to 150 °C absolute maximum rating |
| ESD Rating HBM | ±4000 V, human-body model per ANSI/ESDA/JEDEC JS-001 |
| ESD Rating CDM | ±1500 V, charged-device model per JEDEC JESD22-C101 |
| High-Level Input Voltage, SCL/SDA | 0.7 x VCC to 6 V |
| High-Level Input Voltage, Control Pins | 0.7 x VCC to VCC + 0.5 V for A1, A0, INT1, INT0, RESET |
| Low-Level Input Voltage | -0.5 to 0.3 x VCC V for SCL, SDA, A1, A0, INT1, INT0, RESET |
| Power-On Reset Voltage Rising | 1.2 V typ, 1.5 V max; no load, VI = VCC or GND |
| Power-On Reset Voltage Falling | 0.8 V min, 1 V typ; no load, VI = VCC or GND |
| Switch Output Voltage, 5 V Range | 2.6 V min, 4.5 V max; VCC = 4.5-5.5 V, VSWIN = VCC, ISWout = -100 µA |
| Switch Output Voltage, 3.3 V Range | 1.6 V min, 2.8 V max; VCC = 3.0-3.6 V, VSWIN = VCC, ISWout = -100 µA |
| Switch Output Voltage, 2.5 V Range | 1.0 V min, 1.8 V max; VCC = 2.3-2.7 V, VSWIN = VCC, ISWout = -100 µA |
| Switch Output Voltage, 1.8 V Range | 0.5 V min, 1.1 V max; VCC = 1.65-1.95 V, VSWIN = VCC, ISWout = -100 µA |
| INT High-Level Output Current | 10 µA max; VO = VCC, VCC = 1.65-5.5 V |
| SDA Low-Level Output Current at VOL 0.4 V | 3 mA min, 7 mA max; VCC = 1.65-5.5 V |
| SDA Low-Level Output Current at VOL 0.6 V | 6 mA min, 10 mA max; VCC = 1.65-5.5 V |
| INT Low-Level Output Current | 3 mA min; VOL = 0.4 V, VCC = 1.65-5.5 V |
| Input Leakage Current | -1 to 1 µA; SCL, SDA, SC1-SC0, SD1-SD0, A1, A0, INT1-INT0, RESET |
| Supply Current Operating Mode | 50 µA max; VCC = 5.5 V, fSCL = 400 kHz, tr max = 300 ns, VI = VCC or GND, IO = 0 |
| Supply Current Standby Mode | 0.4 µA typ, 0.55 µA max; VCC = 1.65 V, low inputs or high inputs, IO = 0 |
| Switch On-State Resistance, 5 V Range | 4 Ω min, 10 Ω typ, 16 Ω max; VCC = 4.5-5.5 V, VO = 0.4 V, IO = 15 mA |
| Switch On-State Resistance, 3.3 V Range | 5 Ω min, 13 Ω typ, 20 Ω max; VCC = 3.0-3.6 V, VO = 0.4 V, IO = 15 mA |
| Switch On-State Resistance, 2.5 V Range | 7 Ω min, 16 Ω typ, 45 Ω max; VCC = 2.3-2.7 V, VO = 0.4 V, IO = 10 mA |
| Switch On-State Resistance, 1.8 V Range | 10 Ω min, 25 Ω typ, 70 Ω max; VCC = 1.65-1.95 V, VO = 0.4 V, IO = 10 mA |
| Input Capacitance, Address and Interrupt Inputs | 4.5 pF typ, 6 pF max; A1, A0, INT1-INT0, VI = VCC or GND, VCC = 1.65-5.5 V |
| Input Capacitance, RESET | 4.5 pF typ, 5.5 pF max; VI = VCC or GND, VCC = 1.65-5.5 V |
| Off-State I/O Capacitance, Upstream | 15 pF typ, 19 pF max; SCL, SDA switch off, VI = VCC or GND, VCC = 1.65-5.5 V |
| Off-State I/O Capacitance, Downstream | 6 pF typ, 8 pF max; SC1-SC0, SD1-SD0 switch off, VI = VCC or GND, VCC = 1.65-5.5 V |
| I2C Clock Frequency | 0-100 kHz standard mode; 0-400 kHz fast mode |
| I2C Bus Capacitive Load | 400 pF max for standard-mode and fast-mode I2C |
| Datasheet Status | request_only |
Product Overview
The device operates from a 1.65-5.5 V supply and supports voltage-level translation between 1.8 V, 2.5 V, 3.3 V, and 5 V buses. I2C timing covers 0-100 kHz standard mode and 0-400 kHz fast mode, with a 400 pF maximum I2C bus capacitive load. Inputs are 5.5 V tolerant across all I/O terminals.
Control and fault-handling features include A0 and A1 address pins for up to four devices on the bus, two active-low interrupt inputs, one active-low interrupt output, and an active-low RESET input. At power-up or reset, all switch channels are deselected, and RESET clears the I2C state machine while deselecting both channels.
Package options include TSSOP-14 (PW) 5.00 mm x 4.40 mm and SOIC-14 (D) 8.65 mm x 3.91 mm. The specified operating free-air temperature range is -40 to 85 °C, with standby supply current specified at 0.4 µA typical and 0.55 µA maximum at VCC = 1.65 V.
Key Features
- Two downstream I2C channel pairs from one upstream pair
- 1-of-2 bidirectional translating switch architecture
- Channels selectable over I2C in any combination
- 1.65-5.5 V recommended supply operating range
- Supports 1.8 V, 2.5 V, 3.3 V, and 5 V buses
- Fast-mode I2C operation up to 400 kHz
- All I/O terminals have 5.5 V tolerant inputs
- Power-up and reset deselect all switch channels
- A0 and A1 pins support up to four devices
- Two active-low downstream interrupt inputs
- Active-low RESET clears state machine and channels
- 400 pF maximum I2C bus capacitive load
Typical Applications
- I2C bus channel selection
- Mixed-voltage I2C bus translation
- Two-branch sensor bus routing
- Interrupt aggregation from downstream buses
- Address expansion using A0 and A1
- Fast-mode I2C signal switching
- Low-voltage embedded controller buses
Procurement Notes
When requesting a quote for TCA9543, buyers should confirm the manufacturer, package or case, required quantity, target date code, compliance documents, packing method, destination country and expected delivery schedule.
If alternatives are acceptable, buyers should share the approved vendor list, required electrical or optical limits, package constraints and qualification requirements. Any alternative part should be reviewed by the buyer's engineering team before production use.
For analog and signal-chain sourcing, supply voltage, bandwidth, accuracy, noise level, package, temperature grade, input/output configuration and qualification requirements should be verified before approval.
FAQ
How many downstream I2C channels does the TCA9543 provide?
The TCA9543 provides two downstream channel pairs. The upstream SCL/SDA pair can fan out to SC0/SD0 and SC1/SD1 through bidirectional translating switches selectable by the I2C bus.
What supply voltage range is specified for the TCA9543?
The recommended operating supply voltage range is 1.65-5.5 V. The extracted absolute maximum supply voltage rating is -0.5 to 7 V over the operating free-air temperature range.
What happens to the switch channels at power-up or reset?
At power-up or reset, all switch channels are deselected. The active-low RESET input also resets the I2C state machine and deselects both downstream channels.
What I2C clock rates are supported by the TCA9543?
The I2C timing supports 0-100 kHz standard mode and 0-400 kHz fast mode. The maximum listed I2C clock frequency is 400 kHz for fast-mode operation.
Technical Review & Sourcing Note
Prepared by LDeepAI Component Sourcing Team. Reviewed for RFQ, documentation and alternative sourcing use. Last updated: June 30, 2026.
This page is based on manufacturer datasheet information and LDeepAI sourcing review. Specifications should be verified against the official manufacturer datasheet before final procurement or design approval. Final electrical, optical and reliability approval should be confirmed by the buyer's engineering team.