Overview
The PCA9555DW, produced by Texas Instruments, is a 16-bit I/O expander designed for use with the I2C and SMBus interfaces. This device provides general-purpose remote I/O expansion for most microcontroller families, operating within a voltage range of 2.3V to 5.5V. It is particularly useful in applications where additional I/O pins are needed, such as in ACPI power switches, sensors, push buttons, LEDs, and fans.
Key Specifications
| Parameter | Value |
|---|---|
| Number of I/O | 16 |
| Interface | I2C, SMBus |
| Operating Voltage | 2.3V to 5.5V |
| Operating Temperature | -40°C to 85°C |
| Package Type | 24-SOIC (DW) |
| Interrupt Output | Yes, Open-Drain Active-Low |
| Output Type | Push-Pull |
| Output Source/Sink Current | 10mA, 25mA |
| Clock Frequency | 400 kHz |
| ESD Protection | 2000-V Human-Body Model, 200-V Machine Model, 1000-V Charged-Device Model |
Key Features
- Low Standby-Current Consumption of 1 µA Max
- I2C to Parallel Port Expander
- Open-Drain Active-Low Interrupt Output
- 5-V Tolerant I/O Ports
- Compatible With Most Microcontrollers
- 400-kHz Fast I2C Bus
- Address by Three Hardware Address Pins for Use of up to Eight Devices
- Polarity Inversion Register
- Latched Outputs With High-Current Drive Capability for Directly Driving LEDs
- Latch-Up Performance Exceeds 100 mA Per JESD 78, Class II
- Internal Power-on Reset (POR)
- No Glitch on Power-Up
- Noise Filter on SCL/SDA Inputs
Applications
- ACPI power switches
- Sensors
- Push buttons
- LEDs
- Fans
- Routers (Telecom Switching Equipment)
- Personal Computers
- Personal Electronics
- Industrial Automation Equipment
- Products with GPIO-Limited Processors
Q & A
- What is the PCA9555DW used for?
The PCA9555DW is used for general-purpose remote I/O expansion for most microcontroller families via the I2C interface.
- What is the operating voltage range of the PCA9555DW?
The operating voltage range is 2.3V to 5.5V.
- What types of interfaces does the PCA9555DW support?
The PCA9555DW supports both I2C and SMBus interfaces.
- How many I/O pins does the PCA9555DW provide?
The PCA9555DW provides 16 I/O pins.
- What is the maximum clock frequency of the I2C bus for the PCA9555DW?
The maximum clock frequency is 400 kHz.
- Does the PCA9555DW have an interrupt output feature?
Yes, it has an open-drain active-low interrupt output feature.
- What is the standby current consumption of the PCA9555DW?
The standby current consumption is 1 µA max.
- Is the PCA9555DW ESD protected?
Yes, it exceeds 2000-V Human-Body Model, 200-V Machine Model, and 1000-V Charged-Device Model ESD protection.
- How many devices can share the same I2C/SMBus using the PCA9555DW?
Up to eight devices can share the same I2C/SMBus using three hardware address pins.
- What is the purpose of the Polarity Inversion Register in the PCA9555DW?
The Polarity Inversion Register allows the polarity of the Input Port register to be inverted.
