This is a document about the M41T00AUD product, which is a serial real-time clock (RTC) with audio features. It features a 256 and 512 Hz tone generator, a 300 mW differential audio amplifier with a gain range of -33 to +12 dB, and operates in the temperature range of 0 °C to 70 °C. The RTC is based on M41T00 and offers additional functionalities such as automatic backup switchover circuit, ultra-low backup current, on-chip trickle charge circuit, 400 kHz I2C bus, and calibration register for adjustments.