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Texas Instruments PCF8574ADWRE4 — Interface & Transceivers

PCF8574ADWRE4 I2C GPIO Expander, 8-bit, 100 kHz, SOIC-16

MPNPCF8574ADWRE4
Obsolete

Texas Instruments PCF8574ADWRE4, 8-bit I²C GPIO expander, 100 kHz clock, push-pull outputs, 1 mA source / 25 mA sink per I/O, 2.5V–6V supply, -40°C to 85°C, 16-SOIC wide (7.50 mm), Tape & Reel.

Texas Instruments PCF8574ADWRE4 datasheet (PDF)
Independent supplier — new & surplus stockAuthenticity-screened · ESD-safe packingListing updated Jul 2026

Specifications

PCF8574ADWRE4 specifications
ParameterValue
Output typePush-Pull
MountingSurface Mount
Supply voltage2.5V ~ 6V
Current - output source (Sink)1mA, 25mA
Clock frequency100 kHz
InterfaceI²C
Operating temperature-40°C~85°C
PackageTape & Reel (TR)
FeaturesPOR
Number of i (O)8
Case16-SOIC (0.295\", 7.50mm Width)
Interrupt outputYes

Product details

8-bit I²C GPIO expander in a wide SOIC-16

It communicates over the I²C interface at up to 100 kHz, with eight push-pull I/O pins that can sink 25 mA or source 1 mA each. The wide 16-SOIC package (7.50 mm body width) suits designs where board space allows a larger footprint in exchange for easier hand-assembly or rework. A Power-On Reset (POR) feature ensures the outputs initialize to a known state at power-up.

Supply range and drive capability

Each I/O sinks 25 mA — enough to drive an LED directly or switch a small relay through a transistor — while the 1 mA source current handles logic-level inputs on the host side.

For new designs or BOM lines that need a current-production part, the PCF8574A family (same base product number PCF857) offers the same I²C GPIO expander function with an alternate I²C slave address range, allowing up to eight devices on the same bus versus the PCF8574's eight.

Frequently asked questions

What is the replacement for PCF8574ADWRE4?

The PCF8574A series (e.g., PCF8574ADW, PCF8574APW) is the functional replacement. It is the same 8-bit I²C GPIO expander in the same package options but with a shifted I²C slave address range (0x38–0x3F vs 0x20–0x27), so the bus address must be updated in firmware. The pinout and electrical specs are otherwise identical.

What are the differences between PCF8574 and PCF8574A?

The PCF8574 and PCF8574A are functionally identical 8-bit I²C GPIO expanders. The only difference is the I²C slave address range: the PCF8574 uses addresses 0x20–0x27, while the PCF8574A uses 0x38–0x3F. This allows both types to coexist on the same I²C bus without address conflicts, for up to 16 total expanders.