PCF8574P,112

I/o Expanders Overview

The PCF8574P,112 is a silicon CMOS circuit providing general-purpose remote I/O expansion for microcontroller families via the two-wire bidirectional I2C-bus. It features eight quasi-bidirectional ports (P0–P7) and an active LOW open-drain interrupt output (INT). The device operates between 2.5 V and 6 V with a typical standby current of 2.5 µA. It supports Standard-mode I2C communication at 100 kHz. Addressing is configured via three hardware pins (A0–A2), allowing up to eight devices on one bus. Latched outputs provide high current drive capability for directly driving LEDs.

I/o Expanders Feature Summary

• Eight quasi-bidirectional I/O ports configurable as inputs or outputs without direction registers
• Active LOW open-drain interrupt output triggers when input states differ from register values
• Three hardware address pins enable up to eight devices on a single I2C bus
• Latched outputs support direct LED driving with high current sink capability

I/o Expanders Applications

• LED signs and displays
• Key pads
• Industrial control systems
• PLC applications
• Instrumentation and test measurement

I/o Expanders Procurement Notes

Verify the orderable part number PCF8574P,112 matches the DIP16 package specification. Confirm the temperature range requirement aligns with the -40 °C to +85 °C operating limit. Ensure the I2C bus voltage levels are compatible with the 2.5 V to 6 V supply range. Check that the total package sink current does not exceed 80 mA in high-drive configurations.

I/o Expanders Selection Notes

Select this component when GPIO expansion is required using a standard I2C interface. The PCF8574P variant is suitable for through-hole PCB designs requiring DIP16 packaging. Consider the PCF8574A version if distinct slave addresses are needed alongside PCF8574 devices on the same bus. Evaluate the 100 kHz speed limit against system timing requirements.

I/o Expanders Part Context

The PCF8574 series serves as a remote I/O expander for most microcontroller families. The PCF8574P specifically denotes the DIP16 plastic dual in-line package variant. It differs from the PCF8574A only in its fixed slave address portion, allowing mixed usage on a single bus. This component simplifies system design by reducing pin count requirements for peripheral control.

I/o Expanders Replacement Considerations

PCA9674 offers higher speed (1 MHz Fm+) and greater drive current but requires different addressing. PCA8574 provides 400 kHz operation with similar functionality. Migration to these parts may require software adjustments due to increased bus speeds or different address maps.