Overview
The PCA9544A, produced by Texas Instruments, is a 4-channel, bidirectional translating multiplexer controlled via the I2C bus. This device allows the SCL/SDA upstream pair to fan out to four downstream pairs or channels, with the selection determined by the contents of the programmable control register. It features four active-low interrupt inputs and one active-low interrupt output, which acts as an AND of the four interrupt inputs. The PCA9544A supports voltage-level translation between different bus voltages (1.8-V, 2.5-V, 3.3-V, and 5-V) and is designed for use in various applications requiring I2C bus expansion and management.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Number of Channels | 4 | |
| Operating Temperature Range | -40 to 85 | °C |
| Operating Power Supply Voltage Range | 2.3 to 5.5 | V |
| Maximum Clock Frequency | 400 | kHz |
| Package Types | SOIC (DW), TSSOP (PW), TVSOP (DGV) | |
| Number of Pins | 20 | |
| ESD Protection | 2000-V Human-body model, 200-V Machine model, 1000-V Charged-device model | |
| I/O Pin Tolerance | 5.5-V tolerant |
Key Features
- 1-of-4 bidirectional translating switches
- 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
- Allows 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 (Telecom Switching Equipment)
- Factory Automation
- Products with I2C slave address conflicts (e.g., multiple identical temperature sensors)
Q & A
- What is the PCA9544A?
The PCA9544A is a 4-channel, bidirectional translating multiplexer controlled via the I2C bus. - What are the key features of the PCA9544A?
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 types of packages are available for the PCA9544A?
The PCA9544A is available in SOIC (DW), TSSOP (PW), and TVSOP (DGV) packages. - How many devices can be connected on the I2C Bus using the PCA9544A?
Up to eight devices can be connected on the I2C Bus using the three address pins. - Does the PCA9544A support voltage-level translation?
Yes, it supports voltage-level translation between 1.8-V, 2.5-V, 3.3-V, and 5-V buses. - What is the ESD protection level of the PCA9544A?
The PCA9544A has ESD protection exceeding 2000-V Human-body model, 200-V Machine model, and 1000-V Charged-device model. - Are the I/O pins of the PCA9544A 5-V tolerant?
Yes, all I/O pins are 5-V tolerant. - 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 output acting as an AND of the four interrupt inputs.
