M41T66

M41T66 Serial real-time clock with alarms Features ■ Counters for tenths/hundredths of seconds, seconds, minutes, hours, day, date, month, year, and century 32 KHz crystal oscillator integrating load capacitance and high crystal series resistance operation Oscillator stop detection monitors clock operation Serial interface supports I C bus (400 kHz) 525 nA timekeeping current at 3 V Low operating current of 35 µA (at 400 kHz) Timekeeping down to 1.0 V 1.3 V to 4.4 V I2C bus operating voltage – Allows use in lithium ion rechargeable applications 32 KHz square wave on power-up to drive a microcontroller in low-power mode Programmable (1 Hz to 32 KHz) square wave Programmable alarm with interrupt function Accurate programmable watchdog (from 62.5 ms to 31 min) Software clock calibration to compensate deviation of crystal due to temperature Automatic leap year compensation Operating temperature of –40 to 85 °C Lead-free 16-pin QFN package www.DataSheet.net/ ■ ■ ■ ■ ■ ■ ■ QFN16 3 mm x 3 mm 2 ■ ■ ■ ■ ■ ■ ■ ■ October 2011 Doc ID 15108 Rev 2 1/41 www.st.com 1 Datasheet pdf - http://www.DataSheet4U.co.kr/ Contents M41T66 Contents 1 2 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2.1 2-wire bus characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2.1.1 2.1.2...