PCF8570T datasheet by Philips Semiconductors

PCF8570T Frequently Asked Questions (FAQs)

• What is the maximum frequency of the I2C bus that the PCF8570T can handle?
  The PCF8570T can handle I2C bus frequencies up to 400 kHz, but it's recommended to use a maximum frequency of 100 kHz for reliable operation.
• How do I reset the PCF8570T?
  The PCF8570T does not have a dedicated reset pin. However, you can reset the device by sending a STOP condition on the I2C bus, followed by a START condition. This will reset the device's internal state.
• Can I use the PCF8570T as a level shifter?
  Yes, the PCF8570T can be used as a level shifter between 5V and 3.3V logic levels. However, it's essential to ensure that the input voltage on the VDD pin is within the recommended range (2.5V to 6V) and that the output voltage on the P0-P7 pins is within the recommended range (VDD-0.5V to VDD+0.5V).
• What is the maximum current that the PCF8570T can sink or source?
  The PCF8570T can sink or source up to 25 mA per pin, with a total current limit of 100 mA for all pins combined.
• How do I handle bus contention on the I2C bus when using multiple PCF8570T devices?
  To handle bus contention, ensure that each PCF8570T device has a unique address by connecting the A0, A1, and A2 pins to different logic levels. Also, use a bus arbiter or a multiplexer to manage access to the I2C bus.