PCA9546APWT

Product Overview

Category: Integrated Circuit (IC)

Use: The PCA9546APWT is a multiplexer/demultiplexer IC that allows multiple devices to share a single communication bus. It provides a simple solution for expanding the number of I2C or SMBus ports available in a system.

Characteristics: - 4-channel multiplexer/demultiplexer - I2C-bus and SMBus compatible - Low RON switches - 5V tolerant inputs - Active LOW interrupt output - Power-on reset - Available in TSSOP package

Package: TSSOP-20

Essence: The PCA9546APWT is designed to simplify the management of multiple I2C or SMBus devices by allowing them to share a common bus. It eliminates the need for complex wiring and reduces the number of required I/O pins on the microcontroller.

Packaging/Quantity: The PCA9546APWT is typically sold in reels of 2500 units.

Specifications

• Supply Voltage: 2.3V to 5.5V
• Operating Temperature Range: -40°C to +85°C
• I2C-bus Frequency: Up to 400kHz
• Channel ON Resistance: 7Ω (typical)
• Channel-to-Channel Isolation: >50dB at 1MHz

Pin Configuration

The PCA9546APWT has a total of 20 pins, which are assigned as follows:

1. SCL - Serial Clock Input
2. SDA - Serial Data Input/Output
3. A0 - Address Bit 0
4. A1 - Address Bit 1
5. EN - Enable Input
6. INT - Interrupt Output
7. GND - Ground
8. NC - No Connection
9. NC - No Connection
10. SCL1 - Channel 1 Serial Clock Input/Output
11. SDA1 - Channel 1 Serial Data Input/Output
12. SCL2 - Channel 2 Serial Clock Input/Output
13. SDA2 - Channel 2 Serial Data Input/Output
14. SCL3 - Channel 3 Serial Clock Input/Output
15. SDA3 - Channel 3 Serial Data Input/Output
16. SCL4 - Channel 4 Serial Clock Input/Output
17. SDA4 - Channel 4 Serial Data Input/Output
18. VCC - Supply Voltage
19. NC - No Connection
20. NC - No Connection

Functional Features

• Multiplexes up to four I2C or SMBus channels onto a single bus
• Allows communication with multiple devices using a single microcontroller
• Enables dynamic switching between channels
• Provides power-on reset functionality
• Generates an interrupt signal when any channel is selected

Advantages and Disadvantages

Advantages: - Simplifies the management of multiple I2C or SMBus devices - Reduces wiring complexity - Saves microcontroller I/O pins - Supports high-speed communication up to 400kHz - Low ON resistance for minimal signal distortion

Disadvantages: - Limited to four channels, may not be suitable for systems with a large number of devices - Requires additional control logic for channel selection

Working Principles

The PCA9546APWT operates by selectively connecting one of the four input channels to the output bus. The channel selection is controlled through the A0 and A1 address bits, which can be set by the microcontroller. When a specific channel is selected, the corresponding serial clock (SCL) and serial data (SDA) lines are connected to the main bus, allowing communication with the desired device.

The IC also features an enable (EN) input, which can be used to disable all channels simultaneously. This is useful when the bus needs to be shared with other devices that are not connected through the PCA9546APWT.

Detailed Application Field Plans

The PCA9546APWT finds applications in various fields where multiple I2C or SMBus devices need to be controlled using a single microcontroller. Some potential application areas include:

1. Industrial Automation: Controlling multiple sensors, actuators, and displays in industrial automation systems.
2. Automotive Electronics: Managing various modules such as infotainment systems, climate control, and driver assistance systems.
3. Consumer Electronics: Coordinating communication between different components in smart home devices, wearables, and audio/video equipment.
4. Medical Devices: Enabling communication with multiple sensors, monitors, and control units in medical equipment.

Alternative Models

• PCA9547APW: 8-channel multiplexer/demultiplexer
• PCA9548APW: 8-channel bidirectional switch
• TCA9546APW: 4-channel I2C