Overview
The PCA9544A, produced by Texas Instruments, is a 4-channel, bidirectional translating multiplexer controlled via the I2C bus. This device is designed to manage multiple I2C or SMBus channels, allowing for the selection of one channel at a time. It is particularly useful in scenarios where there are I2C slave address conflicts, such as in systems with multiple identical temperature sensors. The PCA9544A supports voltage translation, enabling communication between devices operating at different voltage levels (1.8V, 2.5V, 3.3V, and 5V) without additional protection. The device includes four active-low interrupt inputs and one active-low interrupt output, which acts as an AND of the four interrupt inputs.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| VCC Range | 1.65 to 5.5 | V |
| Operating Temperature | -40 to 85 | °C |
| Number of Channels | 4 | - |
| Interrupt Inputs | 4 (INT3–INT0) | - |
| Interrupt Output | 1 (Active-low) | - |
| ESD Ratings | 2000-V Human-body model, 200-V Machine model, 1000-V Charged-device model | V |
| Package Options | TVSOP (DGV), SOIC (DW) | - |
| Package Dimensions | TVSOP: 5.00 mm x 4.40 mm, SOIC: 12.8 mm x 7.50 mm | mm |
Key Features
- 1-of-4 bidirectional translating switches for I2C and SMBus compatibility
- Voltage translation capability to support different bus voltages (1.8V, 2.5V, 3.3V, and 5V)
- Four active-low interrupt inputs and one active-low interrupt output
- Power-on reset function to initialize the I2C state machine with no channel selected
- All I/O pins are 5-V tolerant
- External pull-up resistors for bus voltage adjustment
Applications
- Servers and data centers
- Routers and telecom switching equipment
- Factory automation systems
- Products with I2C slave address conflicts, such as multiple identical temperature sensors
Q & A
- What is the PCA9544A used for?
The PCA9544A is used as a 4-channel I2C and SMBus multiplexer to manage multiple I2C or SMBus channels, particularly in scenarios with I2C slave address conflicts.
- What voltage levels does the PCA9544A support?
The PCA9544A supports voltage levels of 1.65V to 5.5V and allows voltage translation between different bus voltages.
- How many interrupt inputs and outputs does the PCA9544A have?
The PCA9544A has four active-low interrupt inputs and one active-low interrupt output.
- What is the purpose of the power-on reset function in the PCA9544A?
The power-on reset function initializes the I2C state machine with no channel selected.
- Are the I/O pins of the PCA9544A 5-V tolerant?
- What types of packages are available for the PCA9544A?
The PCA9544A is available in TVSOP (DGV) and SOIC (DW) packages.
- What are the dimensions of the TVSOP and SOIC packages for the PCA9544A?
The TVSOP package dimensions are 5.00 mm x 4.40 mm, and the SOIC package dimensions are 12.8 mm x 7.50 mm.
- What are some common applications of the PCA9544A?
- Does the PCA9544A require external pull-up resistors?
- What is the ESD rating of the PCA9544A?
