Overview
The PCA9544A, produced by Texas Instruments, is a 4-channel, bidirectional translating multiplexer designed for I2C and SMBus applications. This device allows for the expansion of the I2C bus by providing four downstream channels from a single upstream I2C/SMBus pair. The PCA9544A is controlled via the I2C bus and supports voltage-level translation between different bus voltages, enabling communication between devices operating at 1.8-V, 2.5-V, 3.3-V, and 5-V levels without additional protection.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Number of Channels | 4 | |
| Operating Temperature Range | -40 to 85 | °C |
| Maximum Clock Frequency | 400 | kHz |
| Supply Voltage Range | 2.3 to 5.5 | V |
| Package Options | SOIC, TSSOP, TVSOP, VQFN | |
| Number of Pins | 20 | |
| I/O Pin Tolerance | 5-V tolerant | |
| ESD Protection | 4000-V Human-Body Model, 1500-V Charged-Device Model |
Key Features
- I2C Bus and SMBus compatible
- Four active-low interrupt inputs and one active-low interrupt output
- Three address pins allowing up to eight devices on the I2C bus
- Channel selection via I2C bus
- Power-up with all switch channels deselected
- Low RON switches
- Voltage-level translation between 1.8-V, 2.5-V, 3.3-V, and 5-V buses
- No glitch on power-up
- Supports hot insertion
- Low standby current
Applications
- Servers
- Routers and telecom switching equipment
- Factory automation
- Products with I2C slave address conflicts (e.g., multiple identical temperature sensors)
Q & A
- What is the PCA9544A used for?
The PCA9544A is used as a 4-channel I2C and SMBus multiplexer, allowing the expansion of the I2C bus and enabling communication between devices operating at different voltage levels.
- What are the key features of the PCA9544A?
The key features include I2C and SMBus compatibility, four active-low interrupt inputs, voltage-level translation, and support for hot insertion.
- What is the operating temperature range of the PCA9544A?
The operating temperature range is -40°C to 85°C.
- What is the maximum clock frequency supported by the PCA9544A?
The maximum clock frequency is 400 kHz.
- What are the package options available for the PCA9544A?
The PCA9544A is available in SOIC, TSSOP, TVSOP, and VQFN packages.
- Is the PCA9544A 5-V tolerant?
- What kind of ESD protection does the PCA9544A offer?
The PCA9544A offers 4000-V Human-Body Model and 1500-V Charged-Device Model ESD protection.
- Can the PCA9544A support multiple devices on the same I2C bus?
- What is the purpose of the interrupt inputs and output on the PCA9544A?
The four interrupt inputs (INT3-INT0) and one interrupt output (INT) allow for interrupt handling, with the INT output acting as an AND of the four interrupt inputs.
- Does the PCA9544A support hot insertion?
