Texas Instruments

PCF8575CDW

PCF8575CDW Description

The PCF8575CDW from Texas Instruments is a 16-bit I²C/SMBus I/O expander designed for surface-mount applications, packaged in a 24-SOIC tube. Operating within a 4.5V to 5.5V supply range, it supports a 400 kHz clock frequency, making it suitable for high-speed communication in embedded systems. With open-drain outputs, it offers flexible interfacing for driving LEDs, relays, or other peripherals. The device includes an interrupt output for efficient event-driven designs and features Power-On Reset (POR) for reliable initialization. Though marked as obsolete, it remains a robust choice for legacy designs requiring 16 I/O ports with I²C/SMBus compatibility.

PCF8575CDW Features

• 16-bit I/O Expansion: Provides 16 configurable open-drain I/O pins, each capable of 10mA sink / 25mA source current, ideal for driving low-power devices.
• I²C/SMBus Interface: Supports 400 kHz high-speed communication, enabling seamless integration with microcontrollers.
• Interrupt Output: Reduces polling overhead by signaling host controllers upon input state changes.
• Power-On Reset (POR): Ensures stable initialization at power-up, enhancing system reliability.
• RoHS3 Compliant: Meets environmental standards, suitable for modern eco-conscious designs.
• Wide Voltage Range (4.5V–5.5V): Compatible with standard 5V logic systems.

PCF8575CDW Applications

• Industrial Control Systems: Expands I/O for PLCs, sensor arrays, and actuator control.
• Consumer Electronics: Drives LED matrices, keypads, or display backlighting in smart appliances.
• Embedded Systems: Adds GPIOs to resource-constrained microcontrollers (e.g., Arduino, Raspberry Pi).
• Automotive Interfaces: Used in dashboard controls or infotainment systems (non-safety-critical).
• Legacy Upgrades: Replaces discrete logic in older designs needing I²C-based I/O expansion.

Conclusion of PCF8575CDW

The PCF8575CDW is a versatile I/O expander offering 16-bit GPIO expansion with I²C/SMBus connectivity, suited for applications demanding high-speed communication and low-power driving capability. Its interrupt-driven architecture and POR feature make it reliable for real-time systems, while its obsolete status suggests evaluation of newer alternatives for future-proof designs. Ideal for industrial, consumer, and embedded systems, it balances performance with ease of integration.