PCA9555BS datasheet by NXP Semiconductors

PCA9555BS Frequently Asked Questions (FAQs)

• What is the maximum frequency of the I2C bus that the PCA9555BS can support?
  The PCA9555BS can support I2C bus frequencies up to 400 kHz.
• How do I configure the PCA9555BS to use the internal oscillator?
  To use the internal oscillator, set the OSCEN bit in the Configuration Register (address 0x01) to 1. This will enable the internal oscillator and allow the device to operate without an external clock source.
• What is the purpose of the reset pin (RST) on the PCA9555BS?
  The reset pin (RST) is an active-low input that resets the PCA9555BS to its default state. When the RST pin is pulled low, the device resets and all registers are set to their default values.
• How do I use the PCA9555BS to control LEDs?
  The PCA9555BS can be used to control LEDs by connecting the LEDs to the output pins of the device. The output pins can be configured as either open-drain or push-pull outputs, allowing the device to sink or source current to drive the LEDs.
• What is the maximum current that the PCA9555BS can sink or source on each output pin?
  The PCA9555BS can sink or source up to 25 mA of current on each output pin.