M41T65 - ST Microelectronics

M41T65 Low-power serial real-time clocks

1 Description The M41T6x is a low-power serial real-time clock (RTC) with a built-in 32.768 kHz oscillator. Eight registers are used for the clock/calendar function and are configured in binary-coded decimal (BCD) format. Further eight registers provide status/control of alarm, 32 kHz output, calibration, and watchdog functions. Addresses and data are tran.

Features

• Serial real-time clock (RTC) with alarm functions
  – 400 kHz I²C serial interface
  – Memory mapped registers for seconds, minutes, hours, day, date, month, year, and century
  – Tenths/hundredths of second register
• 350 nA timekeeping current at 3 V
• Time keeping down to 1.0 V
• 1.3 V to 4.4 V I²C bus operating voltage
  – 4.4 V max. VCC suitable for lithium-ion battery operation
• Low operating current of 35 µA (at 400 kHz I²C speed)
• 32 kHz square wave output is on at power-up. Suitable for driving a microcontroller in low-power mode. Can be disabled. (M41T62/64)
• Programmable 1 Hz to 32 kHz.