PCA9545ABS,118 datasheet by NXP Semiconductors

PCA9545ABS,118 Frequently Asked Questions (FAQs)

• What is the maximum frequency of the I2C bus that the PCA9545 can handle?
  The PCA9545 can handle I2C bus frequencies up to 400 kHz, but it's recommended to limit it to 100 kHz for reliable operation.
• Can I use the PCA9545 to switch between multiple I2C buses with different voltage levels?
  Yes, the PCA9545 can switch between multiple I2C buses with different voltage levels, but ensure that the voltage levels are within the recommended operating range of 1.65 V to 5.5 V.
• How do I ensure that the PCA9545 switches correctly between the two I2C buses?
  To ensure correct switching, ensure that the SEL pin is properly driven with a valid logic level (either high or low) and that the bus is not busy during switching. Also, ensure that the I2C bus is idle before switching.
• What is the maximum capacitance of the I2C bus that the PCA9545 can drive?
  The PCA9545 can drive I2C buses with capacitance up to 400 pF, but it's recommended to limit it to 200 pF for reliable operation.
• Can I use the PCA9545 to switch between I2C buses with different clock frequencies?
  Yes, the PCA9545 can switch between I2C buses with different clock frequencies, but ensure that the clock frequencies are within the recommended operating range of 10 kHz to 400 kHz.