Overview
The PCA9555DWRG4, produced by Texas Instruments, is a 16-bit I2C and SMBus I/O expander designed to provide general-purpose remote I/O expansion for most microcontroller families. This device operates within a voltage range of 2.3 V to 5.5 V and is compatible with a wide range of microcontrollers. It features an I2C interface with a clock frequency of up to 400 kHz and includes configuration, input, output, and polarity inversion registers. The PCA9555 is particularly useful in applications where additional I/O ports are needed, such as in servers, routers, personal computers, personal electronics, and industrial automation equipment.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Operating Voltage Range | 2.3 V to 5.5 V | V |
| Number of I/O Bits | 16 | - |
| I2C Clock Frequency | Up to 400 kHz | kHz |
| Standby Current | 1 μA Max | μA |
| I/O Port Configuration | Input or Output | - |
| Polarity Inversion | Active High or Active Low | - |
| Interrupt Output | Open-Drain Active-Low | - |
| ESD Protection | 2000 V HBM, 200 V MM, 1000 V CDM | V |
| Package Type | 24-SOIC (0.295", 7.50mm) | - |
Key Features
- I2C to Parallel Port Expander: Converts I2C signals to parallel port signals, enabling communication between the I2C bus and external devices.
- 5-V Tolerant I/O Ports: Allows the I/O ports to tolerate input voltages up to 5.5 V.
- Low Standby-Current Consumption: Maximum standby current of 1 μA, making it power-efficient.
- Open-Drain Active-Low Interrupt Output: Provides an interrupt signal when any input state differs from its corresponding input port register state.
- Polarity Inversion Register: Allows the polarity of the input port register to be inverted.
- Latched Outputs with High-Current Drive Capability: Capable of directly driving LEDs and other high-current devices.
- ESD Protection: Exceeds JESD 22 standards for human-body model, machine model, and charged-device model.
- Internal Power-On Reset: Initializes the device state machine and sets registers to default values upon power-up.
Applications
- Servers and Routers (Telecom Switching Equipment): Expands I/O capabilities in server and router systems.
- Personal Computers: Enhances I/O functionality in personal computer systems.
- Personal Electronics: Used in various personal electronic devices requiring additional I/O ports.
- Industrial Automation Equipment: Provides additional I/O for industrial automation and control systems.
- Products with GPIO-Limited Processors: Ideal for systems where the microcontroller has limited GPIO pins.
Q & A
- What is the operating voltage range of the PCA9555?
The PCA9555 operates within a voltage range of 2.3 V to 5.5 V.
- How many I/O bits does the PCA9555 provide?
The PCA9555 provides 16 bits of I/O expansion.
- What is the maximum I2C clock frequency supported by the PCA9555?
The PCA9555 supports an I2C clock frequency of up to 400 kHz.
- What is the standby current consumption of the PCA9555?
The maximum standby current consumption is 1 μA.
- Can the PCA9555 tolerate 5V on its I/O ports?
Yes, the PCA9555 has 5-V tolerant I/O ports.
- How does the PCA9555 handle polarity inversion?
The PCA9555 includes a polarity inversion register that allows the polarity of the input port register to be inverted.
- What type of interrupt output does the PCA9555 provide?
The PCA9555 provides an open-drain active-low interrupt output.
- What is the ESD protection level of the PCA9555?
The PCA9555 exceeds JESD 22 standards with 2000 V HBM, 200 V MM, and 1000 V CDM.
- How does the PCA9555 handle power-on reset?
The PCA9555 has an internal power-on reset that initializes the device state machine and sets registers to default values upon power-up.
- What are some common applications of the PCA9555?
The PCA9555 is used in servers, routers, personal computers, personal electronics, industrial automation equipment, and products with GPIO-limited processors.
