DS1305EN/T&R datasheet by Maxim Integrated Products

DS1305EN/T&R Frequently Asked Questions (FAQs)

• What is the recommended power-on reset circuit for the DS1305?
  A simple RC circuit with a 1kΩ resistor and a 10μF capacitor can be used to provide a power-on reset signal to the DS1305. This ensures that the device is properly reset during power-up.
• How do I handle the battery switchover during power failure?
  The DS1305 has an internal switchover circuit that automatically switches to the battery supply during power failure. However, it's recommended to add an external diode (e.g., 1N4148) between the VCC and VBAT pins to prevent backflow of current from the battery to the VCC pin.
• What is the recommended crystal oscillator circuit for the DS1305?
  A parallel resonant crystal oscillator circuit with a 12.5pF capacitor connected between the X1 and X2 pins, and a 10kΩ resistor connected between the X2 pin and ground, is recommended for optimal performance.
• How do I ensure accurate timekeeping with the DS1305?
  To ensure accurate timekeeping, it's essential to use a high-quality crystal oscillator with a frequency tolerance of ±20 ppm or better. Additionally, the DS1305 should be calibrated periodically to account for any deviations in the crystal frequency.
• Can I use the DS1305 with a lithium-ion battery?
  Yes, the DS1305 can be used with a lithium-ion battery. However, it's essential to ensure that the battery voltage is within the recommended operating range of 2.0V to 3.5V, and that the battery is properly protected against overcharge and over-discharge.