Overview
The PCA9554DWR is an 8-bit I2C and SMBus I/O expander produced by Texas Instruments. This device is designed to provide general-purpose remote I/O expansion for most microcontroller families via the I2C interface. It operates within a voltage range of 2.3 V to 5.5 V and is suitable for a wide range of applications requiring additional I/O ports.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Operating Voltage (VCC) | 2.3 to 5.5 | V |
| Operating Temperature | -40 to 85 | °C |
| High-Level Input Voltage (VIH) for SCL, SDA | 0.7 × VCC | V |
| Low-Level Input Voltage (VIL) for SCL, SDA | 0.3 × VCC | V |
| High-Level Output Current (IOH) | -10 | mA |
| Low-Level Output Current (IOL) | 25 | mA |
| Package Type | SSOP (16), VQFN (16) | - |
| Package Body Size (Nominal) | 6.20 mm × 5.30 mm | - |
Key Features
- 8-bit I/O expander with interrupt output
- Operates on I2C and SMBus interfaces
- Configurable I/O ports (input or output) with weak pull-up to VCC
- Polarity Inversion register for input port
- High-current drive capability for directly driving LEDs
- Low current consumption
- Three hardware pins (A0, A1, A2) for programming the fixed I2C address
- Compatible with PCF8574 but requires software changes due to enhancements
Applications
The PCA9554DWR is versatile and can be used in various applications, including:
- Industrial automation and control systems
- Automotive systems requiring additional I/O ports
- Consumer electronics needing I/O expansion
- Embedded systems and microcontroller projects
- Sensor and monitoring systems
Q & A
- What is the operating voltage range of the PCA9554DWR?
The PCA9554DWR operates within a voltage range of 2.3 V to 5.5 V. - What is the operating temperature range of the PCA9554DWR?
The operating temperature range is -40°C to 85°C. - How many devices of the PCA9554 and PCA9554A can be connected on the same I2C/SMBus?
Up to 16 devices (eight of each) can be connected on the same I2C/SMBus. - What is the purpose of the Polarity Inversion register?
The Polarity Inversion register allows for the inversion of the input port polarity (active high or active low). - Can the PCA9554DWR directly drive LEDs?
Yes, the PCA9554DWR has high-current drive capability for directly driving LEDs. - How are the I/O ports configured at power-on?
At power-on, the I/O ports are configured as inputs with a weak pull-up to VCC. - What is the function of the interrupt output (INT) on the PCA9554DWR?
The interrupt output is activated when any input state differs from its corresponding Input Port register state, indicating a change in input state to the system master. - Is the PCA9554DWR compatible with the PCF8574?
Yes, it is pin-to-pin and I2C address compatible, but software changes are required due to enhancements. - How are the fixed I2C addresses programmed on the PCA9554DWR?
The fixed I2C addresses are programmed using three hardware pins (A0, A1, A2). - What are some common applications of the PCA9554DWR?
Common applications include industrial automation, automotive systems, consumer electronics, embedded systems, and sensor and monitoring systems.
