PCA9540BDP datasheet by NXP Semiconductors

PCA9540BDP Frequently Asked Questions (FAQs)

• What is the maximum frequency of the I2C bus that the PCA9540BDP can handle?
  The PCA9540BDP 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 PCA9540BDP to connect multiple I2C buses with different voltage levels?
  Yes, the PCA9540BDP is a voltage-level translator, allowing you to connect I2C buses with different voltage levels, such as 1.8V, 2.5V, 3.3V, or 5V.
• How do I ensure that the PCA9540BDP is properly powered and reset?
  Make sure to connect the VCC pin to a stable power supply, and the RESET pin to a pull-up resistor to VCC. A reset pulse is required after power-up to initialize the device.
• Can I use the PCA9540BDP to isolate I2C buses with different clock domains?
  Yes, the PCA9540BDP provides electrical isolation between the upstream and downstream I2C buses, allowing you to isolate I2C buses with different clock domains or noise levels.
• What is the maximum number of devices that can be connected to each downstream I2C bus?
  The PCA9540BDP can support up to 8 devices on each downstream I2C bus, but the total capacitance of the bus should not exceed 400 pF to ensure reliable operation.