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 square wave output (M41T62/64)
■ Programmable alarm with interrupt function (M41T62/65)
■ 32 kHz crystal oscillator integrates crystal load capacitors, works with high series resistance crystals
■ Oscillator stop detection monitors clock operation
■ Accurate programmable watchdog – 62.5 ms to 31 minutes timeout
■ Software clock calibration. Timekeeping can be adjusted within ± 2 parts per million (± 5 seconds per month)
■ Automatic leap year compensation
■ – 40 to + 85 °C operation
■ Two package options – Very small 3 x 3 mm, lead-free and halogen-free (ECOPACK2) 16-lead QFN – Ultra small 1.5 x 3.2 mm, lead-free and halogen-free (ECOPACK2) 8-pin ceramic leadless chip carrier with embedded 32 kHz crystal - no external oscillator components required (M41T62) Maturity status link M41T62 M41T64 M41T65 Low-power serial real-time clocks (RTCs) with alarm M41T62, M41T64, M41T65 Datasheet DS3840 - Rev 24 - September 2019 For further information contact your local STMicroelectronics sales office.