PCF8574ARGYR

I/o Expanders Overview

The PCF8574ARGYR is an 8-bit remote 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 a maximum clock frequency of 100 kHz. The device features eight quasi-bidirectional I/O ports (P0–P7) with latched outputs capable of directly driving LEDs. It includes three hardware address inputs (A0–A2) for multi-device addressing and an open-drain interrupt output (INT). The component is housed in a 20-pin RGY package (VQFN) with dimensions of 4.50 mm × 3.50 mm. It functions across an operating temperature range of -40°C to +85°C.

I/o Expanders Feature Summary

• Provides general-purpose remote I/O expansion via the two-wire bidirectional I2C interface.
• Features an 8-bit quasi-bidirectional port that can be independently assigned as input or output without data-direction control signals.
• Includes an open-drain interrupt output that triggers on any rising or falling edge of port inputs.
• Offers latched outputs with high-current drive capability suitable for directly activating indicator devices.

I/o Expanders Applications

• Telecom shelters: filter units
• Servers and routers
• Personal computers and electronics
• Industrial automation systems
• Products with GPIO-limited processors

I/o Expanders Procurement Notes

Verify the specific ordering suffix ARGYR corresponds to the VQFN-20 package variant when sourcing. Confirm RoHS compliance status through official manufacturer documentation prior to integration. Ensure the procurement channel provides valid traceability records for production-grade components. Cross-reference the datasheet revision date to ensure alignment with current design specifications.

I/o Expanders Selection Notes

Select this component when system architecture requires expanding microcontroller GPIO resources using the I2C protocol. The PCF8574A variant is distinguished by its specific slave address base compared to the standard PCF8574. Verify that the required I2C bus speed does not exceed 100 kHz if standard mode operation is mandated. Ensure the load current requirements for connected peripherals remain within the specified sink and source limits.

I/o Expanders Part Context

This device belongs to the PCF8574A family of I/O expanders, designed specifically for I2C-based communication. It serves as a peripheral interface solution for microcontrollers lacking sufficient parallel I/O pins. The 'A' designation indicates a unique fixed portion of the slave address, differentiating it from the non-A version to prevent address conflicts on the same bus.

I/o Expanders Replacement Considerations

PCF8574APWRG4

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, allowing for fast rising edges into heavily loaded outputs.

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

No, each quasi-bidirectional I/O must be configured as either an input or an output. However, they do not require a separate data-direction control signal to switch modes.