Overview
The PCA9543APW is a 2-channel I2C bus switch with interrupt logic and reset, manufactured by Texas Instruments. This device is designed to manage multiple I2C buses, allowing for the connection of multiple I2C devices to a single I2C master, thereby resolving potential address conflicts. The PCA9543APW supports bidirectional translating switches, enabling communication between devices operating at different voltage levels (1.8V, 2.5V, 3.3V, and 5V) without additional protection.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| Operating Power-Supply Voltage | 2.3 | - | 5.5 | V |
| I2C Clock Frequency | 0 | - | 400 | kHz |
| I2C Input Rise Time | 20 + 0.1Cb | - | 300 | ns |
| I2C Input Fall Time | 20 + 0.1Cb | - | 300 | ns |
| I2C Bus Free Time Between Stop and Start | 4.7 | - | 1.3 | μs |
| RESET Pulse Duration | 6 | - | - | ns |
| RESET Recovery Time to Start | 0 | - | - | ns |
| I2C Bus Capacitive Load | - | - | 400 | pF |
Key Features
- 1-of-2 bidirectional translating switches
- I2C bus and SMBus compatible
- Two active-low interrupt inputs (INT1–INT0) and one active-low interrupt output (INT)
- Active-low reset (RESET) input to recover from bus-fault conditions
- Voltage-level translation between 1.8V, 2.5V, 3.3V, and 5V buses
- 5.5V tolerant inputs
- Supports hot insertion and low standby current
Applications
- Servers
- Routers (Telecom Switching Equipment)
- Factory Automation
- Products with I2C slave address conflicts (e.g., multiple identical temperature sensors)
Q & A
- What is the primary function of the PCA9543APW?
The PCA9543APW is a 2-channel I2C bus switch that allows multiple I2C devices to be connected to a single I2C master, resolving potential address conflicts.
- What voltage levels does the PCA9543APW support for I2C bus translation?
The device supports voltage-level translation between 1.8V, 2.5V, 3.3V, and 5V buses.
- How does the PCA9543APW handle interrupt signals?
The device has two active-low interrupt inputs (INT1–INT0) and one active-low interrupt output (INT), which acts as an AND of the two interrupt inputs.
- What is the purpose of the RESET input on the PCA9543APW?
The RESET input allows the device to recover from a bus-fault condition by resetting the I2C state machine and deselecting both channels.
- Is the PCA9543APW compatible with SMBus?
Yes, the PCA9543APW is compatible with both I2C and SMBus.
- What is the maximum I2C clock frequency supported by the PCA9543APW?
The device supports I2C clock frequencies up to 400 kHz.
- How does the PCA9543APW handle different bus voltages?
The device allows different bus voltages on each pair, enabling communication between devices operating at different voltage levels without additional protection.
- What is the typical application of the PCA9543APW in resolving I2C address conflicts?
The PCA9543APW is used to resolve I2C address conflicts in applications where multiple identical devices (e.g., temperature sensors) need to be connected to the same I2C bus.
- Is the PCA9543APW suitable for hot insertion?
Yes, the device supports hot insertion.
- What is the thermal performance of the PCA9543APW?
The device has specified thermal metrics such as junction-to-ambient thermal resistance, which varies depending on the package type.
