PCA9539RPW,112 datasheet by NXP Semiconductors

PCA9539RPW,112 Frequently Asked Questions (FAQs)

• What is the maximum frequency of the I2C bus that the PCA9539RPW,112 can support?
  The PCA9539RPW,112 can support I2C bus frequencies up to 400 kHz, but it is recommended to operate at 100 kHz or lower for reliable operation.
• How do I configure the PCA9539RPW,112 to operate in 8-bit or 16-bit mode?
  The PCA9539RPW,112 can be configured to operate in 8-bit or 16-bit mode by setting the MODE pin high or low, respectively, during power-up or reset. The default mode is 8-bit.
• What is the maximum current that can be sourced or sunk by each I/O pin?
  Each I/O pin of the PCA9539RPW,112 can source or sink up to 25 mA of current, but the total current sourced or sunk by all pins should not exceed 100 mA.
• How do I reset the PCA9539RPW,112?
  The PCA9539RPW,112 can be reset by applying a low signal to the RESET pin or by performing a power-on reset (POR). The device will also reset if the I2C bus is idle for more than 100 ms.
• What is the purpose of the INT pin?
  The INT pin is an active-low interrupt output that is asserted when any of the input pins change state. It can be used to wake up a microcontroller or to trigger an interrupt service routine.