Key Selection Information
| Selection Parameter | Confirmed Information |
|---|---|
| Function | 4-channel bidirectional I²C/SMBus switch |
| Channel Control | Any combination of 4 channels selectable by I²C |
| Supply | 1.65 V to 5.5 V |
| Bus | 0 to 400 kHz |
| Addressing | 3 address pins; up to 8 devices |
| Control | Active-low RESET; all channels off at power-up |
| Translation | Supports different pull-up voltages across switched bus segments |
| Exact Package / Packing | TSSOP (PW), 16 pins; 2000-piece large tape and reel |
Product Overview
TCA9546APWR is an I²C bus switch, not a GPIO expander or analog-signal mux. It connects the upstream SDA/SCL pair to any combination of four downstream bus segments under I²C control.
This allows the host to isolate address conflicts, divide bus capacitance and bridge bus segments using different pull-up voltage domains. Because more than one channel can be enabled simultaneously, firmware must avoid reconnecting duplicate slave addresses when that would create contention.
RESET disconnects all channels and can recover the downstream topology without power-cycling the host. The PWR exact code is the leaded TSSOP 2000-piece reel format.
For related devices, see HKEQGOO’s Signal Switches, Multiplexers, Decoders category.
Technical Specifications
| Parameter | Verified Information |
|---|---|
| Manufacturer | Texas Instruments |
| Exact MPN | TCA9546APWR |
| Function | 4-channel bidirectional I²C/SMBus switch |
| Channel Control | Any combination of 4 channels selectable by I²C |
| Supply | 1.65 V to 5.5 V |
| Bus | 0 to 400 kHz |
| Addressing | 3 address pins; up to 8 devices |
| Control | Active-low RESET; all channels off at power-up |
| Translation | Supports different pull-up voltages across switched bus segments |
| Exact Package / Packing | TSSOP (PW), 16 pins; 2000-piece large tape and reel |
| Manufacturer Status | Active / Production |
| Part Marking | PW546A |
Functional Highlights
Channel isolation solves duplicate-address and capacitance problems
Two sensors with the same fixed I²C address can coexist if only one segment is connected at a time. Separate branches also limit how much capacitance the master sees simultaneously.
Voltage translation comes from pass-switch segmentation, not logic-level regeneration
Each branch still needs appropriate pull-ups, and rise-time/current limits must satisfy the bus standard across the selected topology.
Design Considerations
- Ensure firmware never connects conflicting identical-address branches simultaneously.
- Size pull-ups per bus segment and account for pass-switch Ron/rise time.
- Use RESET in the recovery strategy for a downstream bus that becomes stuck low.
Product Status and Exact Order Code
Manufacturer status: Active / Production
Texas Instruments lists TCA9546APWR as Active / Production; TSSOP (PW), 16 pins; 2000-piece large tape and reel; Level-1-260C-UNLIM; −40°C to +85°C; marking PW546A.
Related Engineering Resources
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