DS1321S+ datasheet by Maxim Integrated Products

DS1321S+ Frequently Asked Questions (FAQs)

• What is the recommended power-up sequence for the DS1321S+?
  The recommended power-up sequence is to apply VCC first, followed by VBAT. This ensures that the internal voltage regulator is powered up correctly.
• How do I ensure that the DS1321S+ is in a low-power state when not in use?
  To minimize power consumption, set the CE pin low, and ensure that the SCL and SDA pins are not toggling. Additionally, consider using the device's built-in power-down mode by setting the PD bit in the control register.
• What is the maximum frequency for the I2C interface of the DS1321S+?
  The maximum frequency for the I2C interface is 400 kHz. However, it's recommended to operate at a lower frequency, such as 100 kHz, to ensure reliable communication.
• How do I handle the case where the DS1321S+ loses power and the clock stops?
  When power is restored, the DS1321S+ will automatically restart the clock from the last known time. However, it's recommended to implement a backup power source, such as a battery, to maintain the clock's accuracy.
• What is the accuracy of the internal oscillator of the DS1321S+?
  The internal oscillator of the DS1321S+ has an accuracy of ±10 ppm over the operating temperature range of -40°C to +85°C.