PCF8574AT datasheet by Philips Semiconductors

PCF8574AT Frequently Asked Questions (FAQs)

• What is the maximum frequency of the I2C bus that the PCF8574AT can support?
  The PCF8574AT can support I2C bus frequencies up to 400 kHz.
• How do I reset the PCF8574AT?
  The PCF8574AT can be reset by pulling the SCL line low for at least 2 clock cycles.
• What is the maximum current that the PCF8574AT can sink or source?
  The PCF8574AT can sink or source up to 25 mA of current per I/O pin.
• Can the PCF8574AT be used as an input port expander?
  Yes, the PCF8574AT can be used as an input port expander by configuring the I/O pins as inputs and reading the input values through the I2C bus.
• How do I handle multiple PCF8574AT devices on the same I2C bus?
  Each PCF8574AT device can be assigned a unique address by connecting the A0, A1, and A2 pins to VCC or GND, allowing multiple devices to share the same I2C bus.