PCAL9554CPWJ datasheet by NXP Semiconductors

PCAL9554CPWJ Frequently Asked Questions (FAQs)

• What is the maximum frequency of the I2C bus that the PCAL9554CPWJ can support?
  The PCAL9554CPWJ 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 handle the power-on reset (POR) of the PCAL9554CPWJ?
  The PCAL9554CPWJ has an internal power-on reset (POR) circuit that resets the device when the supply voltage (VDD) is below 0.5 V. To ensure proper operation, it is recommended to add an external capacitor (e.g., 10 nF) between VDD and GND to filter out noise and ensure a clean POR.
• What is the maximum current that can be sourced or sunk by each I/O pin of the PCAL9554CPWJ?
  Each I/O pin of the PCAL9554CPWJ can source or sink up to 25 mA, but it is recommended to limit the current to 10 mA or less to ensure reliable operation and prevent overheating.
• How do I configure the PCAL9554CPWJ for open-drain or push-pull output mode?
  The PCAL9554CPWJ can be configured for open-drain or push-pull output mode by setting the corresponding bits in the configuration register (address 0x03). For open-drain mode, set bit 7 to 1, and for push-pull mode, set bit 7 to 0.
• What is the minimum and maximum voltage that can be applied to the input pins of the PCAL9554CPWJ?
  The input pins of the PCAL9554CPWJ can tolerate voltages between -0.5 V and VDD + 0.5 V. However, it is recommended to keep the input voltage within the range of 0 V to VDD to ensure reliable operation.