Overview
The PCF8574DWRG4, produced by Texas Instruments, is an 8-bit input/output (I/O) expander designed for use with the two-line bidirectional I2C bus. This device is intended for general-purpose remote I/O expansion and is compatible with most microcontroller families. It operates within a voltage range of 2.5V to 6V, making it versatile for various applications. The PCF8574 features an 8-bit quasi-bidirectional I/O port (P0–P7) and includes latched outputs with high-current drive capability, enabling it to directly drive LEDs. The device also includes an open-drain interrupt output and supports up to 16 devices on the same I2C bus, allowing for a total of 128 I/Os.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Operating Voltage Range | 2.5 to 6 | V |
| Operating Temperature Range | -40 to 85 | °C |
| I2C Bus Frequency | 100 kHz | Hz |
| Number of I/O Ports | 8 | - |
| I/O Port Type | Quasi-bidirectional | - |
| Interrupt Output Type | Open-drain | - |
| Maximum Low-Level Output Current | 25 mA | mA |
| Standby Current Consumption | 10 µA (max) | µA |
| Package Types | TSSOP, SOIC, PDIP, QFN, VQFN | - |
Key Features
- I2C to parallel-port expander
- Open-drain interrupt output
- Compatible with most microcontrollers
- Latched outputs with high-current drive capability for directly driving LEDs
- Latch-up performance exceeds 100 mA per JESD 78, Class II
- Low standby-current consumption of 10 µA (max)
- Three hardware address inputs allowing up to 16 devices on the same I2C bus
- Internal Power-On Reset (POR) initializes I/Os as inputs with a weak internal pull-up 100 µA current source
Applications
- Telecom shelters: Filter units
- Servers and routers (telecom switching equipment)
- Personal computers and personal electronics
- Industrial automation
- Products with GPIO-limited processors
Q & A
- What is the operating voltage range of the PCF8574DWRG4?
The operating voltage range is 2.5V to 6V.
- What is the maximum frequency of the I2C bus for the PCF8574DWRG4?
The maximum frequency of the I2C bus is 100 kHz.
- How many I/O ports does the PCF8574DWRG4 have?
The device has 8 quasi-bidirectional I/O ports.
- What type of interrupt output does the PCF8574DWRG4 feature?
The device features an open-drain interrupt output.
- Can the PCF8574DWRG4 directly drive LEDs?
- What is the standby current consumption of the PCF8574DWRG4?
The standby current consumption is 10 µA (max).
- How many devices of the PCF8574DWRG4 can be connected on the same I2C bus?
Up to 16 devices can be connected on the same I2C bus, supporting up to 128 I/Os.
- What is the purpose of the internal Power-On Reset (POR) in the PCF8574DWRG4?
The internal Power-On Reset initializes the I/Os as inputs with a weak internal pull-up 100 µA current source.
- What are some common applications of the PCF8574DWRG4?
Common applications include telecom shelters, servers, routers, personal computers, personal electronics, industrial automation, and products with GPIO-limited processors.
- What types of packages are available for the PCF8574DWRG4?
The device is available in TSSOP, SOIC, PDIP, QFN, and VQFN packages.
