Overview
The PCA9546A, produced by Texas Instruments, is a low-voltage, 4-channel I2C and SMBus switch. This device is designed to manage multiple I2C or SMBus channels, allowing for flexible and efficient communication between different components on the bus. It supports both Standard-Mode (100 kHz) and Fast-Mode (400 kHz) operation, making it versatile for various applications. The PCA9546A features a single 8-bit control register that enables and disables the four switch channels, facilitating easy control via the I2C bus.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Operating Power-Supply Voltage Range | 2.3 to 5.5 | V |
| Input Voltage Tolerance | 5.5 | V |
| Clock Frequency Range | 0 to 400 | kHz |
| Operating Free-Air Temperature Range | -40 to 85 | °C |
| Package Types | SOIC (DW), TSSOP (PW), VQFN (RGV, RGY) | |
| ESD Protection | 2000-V Human-Body Model, 1000-V Charged-Device Model | |
| Latch-Up Performance | Exceeds 100 mA Per JESD 78 |
Key Features
- 1-of-4 bidirectional translating switches for I2C buses
- I2C bus and SMBus compatible
- Active-low reset input
- Three address pins, allowing up to eight PCA9546A devices on the I2C bus
- Channel selection via I2C bus, in any combination
- 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
The PCA9546A is suitable for a variety of applications where multiple I2C or SMBus devices need to be managed. These include:
- Industrial automation systems
- Consumer electronics
- Medical devices
- Automotive systems
- Embedded systems requiring multiple I2C/SMBus interfaces
Q & A
- What is the primary function of the PCA9546A?
The PCA9546A is a 4-channel I2C and SMBus switch that allows for the management of multiple I2C or SMBus channels.
- What are the supported I2C bus modes?
The PCA9546A supports both Standard-Mode (100 kHz) and Fast-Mode (400 kHz) operation.
- How many PCA9546A devices can be connected on the same I2C bus?
Up to eight PCA9546A devices can be connected on the same I2C bus using the three address pins.
- What is the purpose of the active-low reset input?
The active-low reset input allows the PCA9546A to recover from a situation where one of the downstream I2C buses is stuck in a low state.
- Can the PCA9546A handle different voltage levels on the I2C bus?
Yes, the PCA9546A allows voltage-level translation between 1.8-V, 2.5-V, 3.3-V, and 5-V buses.
- Is the PCA9546A tolerant to high input voltages?
Yes, all I/O pins of the PCA9546A are 5.5-V tolerant.
- What is the operating power-supply voltage range of the PCA9546A?
The operating power-supply voltage range is from 2.3 V to 5.5 V.
- Does the PCA9546A support hot insertion?
Yes, the PCA9546A supports hot insertion.
- What is the standby current of the PCA9546A?
The PCA9546A has a low standby current.
- What are the available package types for the PCA9546A?
The PCA9546A is available in SOIC (DW), TSSOP (PW), and VQFN (RGV, RGY) packages.
