PCA9539AHF,128 datasheet by NXP Semiconductors

PCA9539AHF,128 Frequently Asked Questions (FAQs)

• What is the maximum frequency of the I2C bus that the PCA9539AHF can support?
  The PCA9539AHF can support I2C bus frequencies up to 400 kHz.
• How do I configure the PCA9539AHF to use an external pull-up resistor?
  To use an external pull-up resistor, connect the resistor between the SCL/SDA pins and the VCC pin. The recommended value is 1 kΩ to 10 kΩ.
• What is the maximum current that the PCA9539AHF can sink or source per output pin?
  The PCA9539AHF can sink or source up to 25 mA per output pin.
• How do I reset the PCA9539AHF?
  The PCA9539AHF 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 PCA9539AHF as a level translator?
  Yes, the PCA9539AHF can be used as a level translator. It can translate signals from a lower voltage domain to a higher voltage domain, or vice versa.