1 Features
• Low standby-current consumption of 10μA max
• I2C to parallel-port expander
• Open-drain interrupt output
• Compatible with most microcontrollers
• Latched outputs with high-current drive capability
for directly driving LEDs
• Latch-up performance exceeds 100mA per JESD
78, Class II

2 Applications
• Telecom shelters: filter units
• Servers
• Routers (telecom switching equipment)
• Personal computers
• Personal electronics
• Industrial automation
• Products with GPIO-limited processors

3 Description
This 8-bit input/output (I/O) expander for the two-line
bidirectional bus (I2C) is designed for 2.5V to 6V VCC
operation.
The PCF8574 device provides general-purpose
remote I/O expansion for most microcontroller families
by way of the I2C interface [serial clock (SCL), serial
data (SDA)].
The device features an 8-bit quasi-bidirectional I/O
port (P0–P7), including latched outputs with highcurrent
drive capability for directly driving LEDs. Each
quasi-bidirectional I/O can be used as an input or
output without the use of a data-direction control
signal. At power on, the I/Os are high. In this mode,
only a current source to VCC is active.