Overview
The PCA9546ADT, produced by Texas Instruments, is a low-voltage 4-channel I2C and SMBus switch with reset functions. This device is designed to manage multiple I2C buses, allowing for the selection of individual or combined channels through the I2C bus. It is particularly useful in scenarios where multiple devices share the same I2C slave address or where different voltage levels need to be translated between devices.
Key Specifications
| Parameter | Min | Max | Unit |
|---|---|---|---|
| VCC Supply Voltage | -0.5 | 7 | V |
| Input Voltage | -0.5 | 7 | V |
| Input Current | -20 | 20 | mA |
| Output Current | -25 | 25 | mA |
| Operating Free-Air Temperature | -40 | 85 | °C |
| Storage Temperature | -65 | 150 | °C |
| Clock Frequency | 0 | 400 | kHz |
| Power-Supply Voltage Range | 2.3 | 5.5 | V |
| ESD Protection | - | - | 2000-V Human-Body Model, 1000-V Charged-Device Model |
Key Features
- 1-of-4 bidirectional translating switches for I2C and SMBus compatibility
- Active-low reset input to recover from stuck low states on downstream I2C buses
- 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 for minimal voltage drop
- 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
- 5.5 V tolerant inputs
- Latch-up performance exceeds 100 mA per JESD 78
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 PCA9546ADT used for?
The PCA9546ADT is used to manage multiple I2C buses, allowing for the selection of individual or combined channels and voltage-level translation between different voltage buses.
- What is the operating voltage range of the PCA9546ADT?
The operating power-supply voltage range is from 2.3 V to 5.5 V.
- 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 device to recover from a situation where one of the downstream I2C buses is stuck in a low state.
- Does the PCA9546ADT support hot insertion?
- What is the clock frequency range supported by the PCA9546ADT?
The clock frequency range is from 0 to 400 kHz.
- Is the PCA9546ADT ESD protected?
- What package types are available for the PCA9546ADT?
The PCA9546ADT is available in various packages including SOIC, TSSOP, and TVSOP.
- Can the PCA9546ADT handle different voltage levels on each channel?
- What is the typical standby current of the PCA9546ADT?
The PCA9546ADT has a low standby current, which is beneficial for power-sensitive applications.
