VN800S datasheet by STMicroelectronics

VN800S Frequently Asked Questions (FAQs)

• What is the recommended PCB layout for optimal performance of the VN800S?
  A good PCB layout for the VN800S involves keeping the power supply lines (VCC and GND) as short as possible, using a solid ground plane, and placing decoupling capacitors close to the device. A 4-layer PCB with a dedicated power plane and a solid ground plane is recommended.
• How do I ensure reliable communication between the VN800S and the microcontroller?
  To ensure reliable communication, use a dedicated SPI bus with a maximum length of 30 cm, and add a 100-ohm series resistor to the SCK line to reduce ringing. Also, ensure that the microcontroller's SPI clock frequency is within the VN800S's specified range (up to 10 MHz).
• What is the recommended power-up sequence for the VN800S?
  The recommended power-up sequence is to apply VCC first, followed by the input voltage (VIN) and then the enable signal (EN). This ensures that the internal voltage regulators are properly initialized.
• How do I handle the VN800S's overcurrent protection feature?
  The VN800S has a built-in overcurrent protection feature that limits the output current to 1.5 A. If an overcurrent condition is detected, the device will automatically shut down. To handle this, implement a retry mechanism in your firmware to reset the device and retry the operation after a short delay.
• What is the maximum allowed voltage on the input pins of the VN800S?
  The maximum allowed voltage on the input pins (VIN, SCK, MOSI, MISO, and CS) is 6 V. Exceeding this voltage may damage the device.