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Texas Instruments PCF8574DWRE4 — Interface & Transceivers

PCF8574DWRE4 I2C I/O Expander, 8-Bit, 100 kHz, 16-SOIC

MPNPCF8574DWRE4
End of Life

Texas Instruments PCF8574DWRE4, 8-bit I2C I/O expander, 100 kHz clock, 2.5V–6V supply, push-pull outputs, interrupt output, POR, -40°C to 85°C, 16-SOIC.

$0.2900Ref. price · indicative, final on quote
Texas Instruments PCF8574DWRE4 datasheet (PDF)
Independent supplier — new & surplus stockAuthenticity-screened · ESD-safe packingListing updated Aug 2026

Specifications

PCF8574DWRE4 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 I/O expander for mixed-voltage buses

The PCF8574DWRE4: It operates from a 2.5V to 6V supply, making it equally at home on a 3.3V microcontroller rail or a legacy 5V backplane. The 100 kHz standard-mode I2C interface keeps wiring simple and is compatible with virtually any MCU with an I2C peripheral. Each of the eight I/O pins can sink up to 25 mA (source 1 mA), enough to drive an LED or a small relay coil directly without an external transistor.

Supply range and I2C address flexibility

The 2.5V to 6V supply range covers 3.3V and 5V logic families without a level shifter. The I2C address is set by three hardware address pins (A0, A1, A2), allowing up to eight of these expanders on the same bus. The POR feature ensures the outputs power up in a known high-impedance state, so downstream loads don't see an undefined glitch during power-on.

The wide supply range and standard I2C interface mean it can be dropped into existing 5V or 3.3V designs without a board spin.

Housed in a 16-SOIC (0.295", 7.50 mm width) package, surface-mount only.

Frequently asked questions

What is the I2C address of the PCF8574?

The I2C address is determined by the three hardware address pins, allowing up to eight devices on the same bus. The base address is 0x20 (0100000) when all three pins are tied low.

Can the PCF8574 work with 3.3V logic?

Yes, the 2.5V to 6V supply range covers 3.3V operation directly. The I2C bus levels track VDD, so a 3.3V supply produces 3.3V logic levels on SDA and SCL.