Pinout

PCF8574 I2C port expander (DIP-16) pinout

Pins

Supply voltage	2.5–6 V
Interface	I2C, 100 kHz (standard mode)
I2C address	PCF8574: 0x20–0x27; PCF8574A: 0x38–0x3F (set by A0–A2)
I/O	8 quasi-bidirectional pins
Output sink current	25 mA max per pin (100 mA total)
Output source current	Weak: ≈ 100 µA typ pull-up — drive LEDs by sinking
Standby current	≈ 2.5 µA typ, 10 µA max
Interrupt	Open-drain INT, active low, on any input change
Operating temperature	−40–85 °C
Package	DIP-16, SOIC-16, TSSOP-20

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