PCA9540BD datasheet by NXP Semiconductors

PCA9540BD Frequently Asked Questions (FAQs)

• What is the maximum frequency of the I2C bus that PCA9540BD can support?
  The PCA9540BD can support I2C bus frequencies up to 400 kHz, but it's recommended to limit the frequency to 100 kHz to ensure reliable operation.
• Can I use PCA9540BD to switch between multiple I2C masters?
  No, the PCA9540BD is designed to switch between multiple I2C buses, not multiple I2C masters. It's intended to allow a single I2C master to access multiple I2C buses.
• How do I ensure that the PCA9540BD switches correctly between the I2C buses?
  To ensure correct switching, make sure to follow the recommended switching sequence in the datasheet, and use the EN (enable) pin to disable the switch during power-up and power-down to prevent bus contention.
• What is the maximum capacitance of the I2C bus that PCA9540BD can drive?
  The PCA9540BD can drive I2C buses with capacitance up to 400 pF, but it's recommended to keep the bus capacitance as low as possible to ensure reliable operation.
• Can I use PCA9540BD to switch between I2C buses with different voltage levels?
  No, the PCA9540BD is not designed to switch between I2C buses with different voltage levels. It's intended to operate within a single voltage domain.