PCF8574ARGYRG4

I/o Expanders Overview

The PCF8574ARGYRG4 is a remote 8-bit I/O expander for the I2C bus, manufactured by Texas Instruments. It operates within a supply voltage range of 2.5 V to 6 V and supports an operating temperature range from -40 °C to 85 °C. The device features an 8-bit quasi-bidirectional I/O port (P0–P7) with latched outputs capable of directly driving LEDs. It utilizes a standard I2C interface with three hardware address inputs (A0–A2), allowing up to eight devices on a single bus. The component is housed in a 20-pin Very Thin Quad Flat No-Lead (VQFN) package.

I/o Expanders Feature Summary

• Provides general-purpose remote I/O expansion via the I2C interface without requiring data-direction control signals.
• Features latched outputs with high-current drive capability suitable for directly driving LEDs.
• Includes an open-drain interrupt output that triggers on any rising or falling edge of port inputs.
• Ensures robust performance with latch-up protection exceeding 100 mA per JESD 78, Class II.

I/o Expanders Applications

• Telecom shelters including filter units
• Servers and routers for telecom switching equipment
• Personal computers and personal electronics
• Industrial automation systems
• Products utilizing GPIO-limited processors

I/o Expanders Procurement Notes

Verify the specific ordering suffix RGYRG4 corresponds to the 20-pin VQFN package variant when sourcing. Confirm compliance with RoHS standards and ensure the supplier provides valid traceability documentation. Check for moisture sensitivity level 2 requirements during storage and handling procedures.

I/o Expanders Selection Notes

Select this component when expanding microcontroller I/O capabilities over an I2C bus is required. Ensure the system voltage falls between 2.5 V and 6 V. Consider the open-drain interrupt feature if event-driven processing is necessary. Verify that the 20-pin VQFN footprint matches the PCB layout constraints.

I/o Expanders Part Context

This part belongs to the PCF8574A family of I2C I/O expanders. The 'RGY' suffix indicates the 20-pin VQFN package, while 'RG4' typically denotes lead-free and RoHS-compliant manufacturing. It serves as a peripheral device to extend digital input and output lines for controllers lacking sufficient pins.

I/o Expanders Replacement Considerations

PCF8574ARGRG4: Identical electrical specifications and pinout in the same 20-pin VQFN package.

I/o Expanders FAQ

How is the interrupt signal reset?

The interrupt circuit resets when data on the port generating the interrupt is changed back to its original setting, or when data is read from or written to that specific port.

What is the state of the I/Os at power-on?

At power-on, all I/Os are high. In this mode, only a current source to VCC is active, which allows them to be used as inputs immediately after initialization.

Can the I/O ports be used as both inputs and outputs simultaneously?

Yes, each quasi-bidirectional I/O can function as either an input or an output without a dedicated data-direction control signal, provided the I/Os are high before being used as inputs.