This document describes the features and characteristics of the M41T81S serial access real-time clock (RTC) with alarms, including counters, 32 KHz crystal oscillator, serial interface, ultra-low battery supply current, etc.
The M41T81S is a low-power serial real-time clock (RTC) featuring a built-in 32.768 kHz oscillator controlled by an external crystal or embedded in specific packages. It utilizes eight bytes of SRAM for the clock/calendar function and includes additional registers for alarms, watchdog timers, and square wave outputs.
| Supply voltage (VCC) | 2.7 to 5.5 V |
|---|---|
| Power-down current | 0.6 µA (typ) |
| Operating temperature | -40 to 85 °C |
| Oscillator frequency | 32 KHz |
The device operates with a supply voltage between 2.7 V and 5.5 V.
Yes, it includes a built-in 32 KHz crystal oscillator with integrated load capacitance.
The ultra-low battery supply current in power-down mode is typically 0.6 µA.