PCF8574APWR datasheet by Texas Instruments

PCF8574APWR Frequently Asked Questions (FAQs)

• What is the maximum frequency of the I2C bus that the PCF8574APWR can support?
  The PCF8574APWR can support I2C bus frequencies up to 400 kHz, but it's recommended to operate at 100 kHz for reliable operation.
• How do I handle the internal pull-up resistors on the I2C bus?
  The internal pull-up resistors on the I2C bus are enabled by default. To disable them, connect an external pull-up resistor to the SCL and SDA lines. The recommended value is 2.2 kΩ for 5V operation and 1.5 kΩ for 3.3V operation.
• What is the maximum current that the PCF8574APWR can sink or source on each I/O pin?
  The PCF8574APWR can sink or source up to 25 mA on each I/O pin, but the total current should not exceed 100 mA for the entire device.
• How do I reset the PCF8574APWR?
  The PCF8574APWR can be reset by pulling the RESET pin low for at least 1 ms. This will reset the device to its default state.
• Can I use the PCF8574APWR as a level translator between 3.3V and 5V systems?
  Yes, the PCF8574APWR can be used as a level translator between 3.3V and 5V systems. The device can operate with a supply voltage range of 2.5V to 6V, making it suitable for level translation applications.