Overview
The PCA9543A, produced by Texas Instruments, is a dual bidirectional translating switch controlled by the I2C bus. This device is designed to fan out the SCL/SDA upstream pair to two downstream pairs or channels, allowing for flexible channel selection and voltage-level translation. It is particularly useful in systems where multiple I2C devices need to be managed, especially in scenarios with address conflicts or different voltage levels.
Key Specifications
| Parameter | Description | Value |
|---|---|---|
| Operating Temperature Range | -40°C to 85°C | -40°C to 85°C |
| Package | SOIC (D) | 14 pins |
| Operating Power-Supply Voltage Range | 2.3 V to 5.5 V | 2.3 V to 5.5 V |
| I2C Bus Frequency | Up to 400 kHz | Up to 400 kHz |
| Number of Channels | 2 | 2 |
| Interrupt Inputs | Two active-low interrupt inputs (INT1–INT0) | Two active-low interrupt inputs (INT1–INT0) |
| Interrupt Output | One active-low interrupt output (INT) | One active-low interrupt output (INT) |
| Reset Input | Active-low reset (RESET) input | Active-low reset (RESET) input |
| Voltage-Level Translation | Allows translation between 1.8-V, 2.5-V, 3.3-V, and 5-V buses | Allows translation between 1.8-V, 2.5-V, 3.3-V, and 5-V buses |
| ESD Protection | 2000-V human-body model (A114-A), 1000-V charged-device model (C101) | 2000-V human-body model (A114-A), 1000-V charged-device model (C101) |
Key Features
- 1-of-2 bidirectional translating switches
- I2C bus and SMBus compatible
- Two active-low interrupt inputs (INT1–INT0)
- One active-low interrupt output (INT)
- Active-low reset (RESET) input
- Two address pins allowing up to four PCA9543A devices on the I2C bus
- Channel selection via I2C bus, in any combination
- Power-up with all switch channels deselected
- Low RON switches
- No glitch on power-up
- Supports hot insertion
- Low standby current
- 5.5-V tolerant inputs
- Latch-up performance exceeds 100-mA per JESD78
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 PCA9543A used for?
The PCA9543A is a dual bidirectional translating switch controlled by the I2C bus, used to manage multiple I2C devices, especially in scenarios with address conflicts or different voltage levels.
- What is the operating temperature range of the PCA9543A?
The operating temperature range is -40°C to 85°C.
- What is the maximum I2C bus frequency supported by the PCA9543A?
The PCA9543A supports I2C bus frequencies up to 400 kHz.
- How many channels does the PCA9543A have?
The PCA9543A has two channels.
- What type of interrupt inputs does the PCA9543A have?
The PCA9543A has two active-low interrupt inputs (INT1–INT0).
- Does the PCA9543A support voltage-level translation?
Yes, it allows translation between 1.8-V, 2.5-V, 3.3-V, and 5-V buses.
- What kind of ESD protection does the PCA9543A offer?
The PCA9543A offers 2000-V human-body model (A114-A) and 1000-V charged-device model (C101) ESD protection.
- Can the PCA9543A be used in hot insertion scenarios?
Yes, the PCA9543A supports hot insertion.
- What is the purpose of the active-low reset input on the PCA9543A?
The active-low reset input allows the PCA9543A to recover from a situation where one of the downstream I2C buses is stuck in a low state.
- How many PCA9543A devices can be connected on the same I2C bus?
Up to four PCA9543A devices can be connected on the same I2C bus using the two address pins.
