DS1284QN+ datasheet by Maxim Integrated Products

DS1284QN+ Frequently Asked Questions (FAQs)

• What is the recommended layout and routing for the crystal oscillator circuit?
  The recommended layout and routing for the crystal oscillator circuit can be found in the Maxim Integrated Products application note 3581, 'Crystal Oscillator Circuits'. It is essential to follow the recommended layout and routing to ensure the oscillator starts reliably and operates within the specified frequency range.
• How do I ensure the DS1284QN+ is properly reset during power-up?
  To ensure the DS1284QN+ is properly reset during power-up, connect the RST pin to a 10kΩ pull-up resistor to VCC, and add a 0.1μF capacitor from RST to GND. This will ensure the device is properly reset and starts up in a known state.
• What is the maximum allowed capacitance on the X1 and X2 pins?
  The maximum allowed capacitance on the X1 and X2 pins is 20pF. Exceeding this value may affect the oscillator's start-up time and frequency stability.
• Can I use a quartz crystal with a different frequency than 32.768kHz?
  No, the DS1284QN+ is designed to work with a 32.768kHz quartz crystal. Using a crystal with a different frequency may not work or may result in unreliable operation.
• How do I handle the battery switchover during power failure?
  To handle the battery switchover during power failure, connect the VBAT pin to a battery with a diode (e.g., 1N4148) in series to prevent backflow of current. The device will automatically switch to the battery when the main power supply (VCC) fails.