PCF8574AT/3 datasheet by NXP Semiconductors

PCF8574AT/3 Frequently Asked Questions (FAQs)

• What is the maximum frequency of the I2C bus that the PCF8574AT/3 can handle?
  The PCF8574AT/3 can handle I2C bus frequencies up to 400 kHz, but it's recommended to use a maximum frequency of 100 kHz for reliable operation.
• How do I reset the PCF8574AT/3?
  The PCF8574AT/3 can be reset by pulling the SCL line low for at least 10 ms. This will reset the device and clear all internal registers.
• What is the maximum current that can be sourced or sunk by the PCF8574AT/3?
  The PCF8574AT/3 can source or sink up to 20 mA of current per I/O pin, but the total current should not exceed 100 mA for the entire device.
• Can I use the PCF8574AT/3 as a level shifter?
  Yes, the PCF8574AT/3 can be used as a level shifter, but it's not recommended as it's not designed for this purpose. The device is intended for I/O expansion and not for level shifting.
• How do I handle bus contention on the I2C bus when using multiple PCF8574AT/3 devices?
  To handle bus contention, use a unique address for each PCF8574AT/3 device by connecting the A0, A1, and A2 pins to different logic levels. This will ensure that each device has a unique address on the I2C bus.