Overview
The PCA9554DW, produced by Texas Instruments, is a remote 8-bit I2C and SMBus I/O expander with an interrupt output. This device is designed to provide general-purpose remote I/O expansion for most microcontroller families via the I2C interface. It operates within a power-supply voltage range of 2.3 V to 5.5 V, making it versatile for various applications. The PCA9554DW features an open-drain active-low interrupt output, which allows the remote I/O to inform the microcontroller of any changes in input states without continuous communication over the I2C bus. This device is pin-to-pin and I2C address compatible with the PCF8574, although software changes are necessary due to the enhancements in the PCA9554DW.
Key Specifications
| Specification | Value |
|---|---|
| Interface Type | I2C, Serial, SMBus |
| Number of I/Os | 8 |
| Interrupt Output | With Interrupt |
| Supply Voltage Range | 2.3 V to 5.5 V |
| Operating Temperature Range | -40°C to 85°C |
| Package Type | SOIC (DW), SSOP, VQFN |
| Package Size | 6.20 mm × 5.30 mm (SSOP) |
| I2C Bus Speed | 400 kHz |
| High-Level Input Voltage | 0.7 × VCC |
| Low-Level Input Voltage | 0.3 × VCC |
| High-Level Output Current | -10 mA |
| Low-Level Output Current | 25 mA |
Key Features
- I2C to Parallel Port Expander
- Open-Drain Active-Low Interrupt Output
- 5-V Tolerant I/Os
- 400-kHz Fast I2C Bus
- Three Hardware Address Pins Allow up to Eight Devices on the I2C/SMBus
- Input/Output Configuration Register
- Polarity Inversion Register
- Internal Power-On Reset
- Power-Up With All Channels Configured as Inputs
- No Glitch On Power Up
- Latched Outputs With High-Current Drive Capability for Directly Driving LEDs
- ESD Protection Exceeds JESD 22 (2000-V Human-Body Model, 200-V Machine Model, 1000-V Charged-Device Model)
Applications
The PCA9554DW is suitable for a variety of applications that require remote I/O expansion. These include:
- Industrial Automation Systems
- Consumer Electronics
- Automotive Systems
- Medical Devices
- Any system requiring additional I/O ports via an I2C or SMBus interface.
Q & A
- What is the PCA9554DW?
The PCA9554DW is a remote 8-bit I2C and SMBus I/O expander with an interrupt output, designed for general-purpose remote I/O expansion. - What is the operating voltage range of the PCA9554DW?
The operating voltage range is 2.3 V to 5.5 V. - How many I/Os does the PCA9554DW have?
The PCA9554DW has 8 I/Os. - What is the maximum I2C bus speed of the PCA9554DW?
The maximum I2C bus speed is 400 kHz. - Can the PCA9554DW directly drive LEDs?
Yes, the latched outputs have high-current drive capability for directly driving LEDs. - How many devices can share the same I2C/SMBus?
Up to eight devices can share the same I2C/SMBus using the three hardware address pins. - Is the PCA9554DW compatible with other devices?
The PCA9554DW is pin-to-pin and I2C address compatible with the PCF8574, though software changes are required. - What kind of ESD protection does the PCA9554DW have?
The PCA9554DW has ESD protection exceeding JESD 22 standards (2000-V Human-Body Model, 200-V Machine Model, 1000-V Charged-Device Model). - What is the purpose of the interrupt output on the PCA9554DW?
The interrupt output is used to inform the microcontroller of any changes in input states without continuous communication over the I2C bus. - What is the operating temperature range of the PCA9554DW?
The operating temperature range is -40°C to 85°C.
