M41T65 Serial real-time clock (RTC) with alarm

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. An additional 8 registers provide status/control of alarm, 32 KHz output, calibration, and watchdog functions. Addresses and data are transferred serially via a two line, bidirectional I²C interface. The built-in address register is incremented automatically after each WRITE or READ data byte.

Functions available to the user include a time-of-day clock/calendar, alarm interrupts (M41T62/65), 32 KHz output (M41T62/63/64), programmable square wave output (M41T62/63/64), and watchdog output (M41T63/65). The eight clock address locations contain the century, year, month, date, day, hour, minute, second and tenths/hundredths of a second in 24-hour BCD format. Corrections for 28-, 29- (leap year), 30- and 31-day months are made automatically.

The M41T6x is supplied in two very small packages: a tiny, 3 mm x 3 mm 16-pin QFN which requires a user-supplied 32 KHz crystal, and an ultra-small 1.5 mm x 3.2 mm LCC with embedded crystal - no external crystal is required.

技术特性
  • 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 seconds register
  • 350 nA timekeeping current at 3 V
  • Timekeeping down to 1.0 V
  • 1.3 V to 4.4 V I²C bus operating voltage
    • 4.4 V max VCCsuitable for lithium-ion battery operation
  • Low operating current of 35 μA (at 400 kHz)
  • 32 KHz square wave output is on at power-up. Suitable for driving a microcontroller in low-power mode. Can be disabled. (M41T62/63/64)
  • Programmable 1 Hz to 32 KHz square wave output (M41T62/63/64)
  • 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 min timeout
  • Software clock calibration. Can adjust timekeeping to within ±2 parts per million (±5 seconds per month)
  • Automatic leap year compensation
  • –40 to +85 °C operation
  • Two package options:
    • Very small 3 mm x 3 mm, lead-free & halogen-free (ECOPACK2®) 16-lead QFN
    • Ultra-small 1.5 mm x 3.2 mm, lead-free & halogen-free (ECOPACK2®) 8-pin ceramic leadless chip carrier with embedded 32 KHz crystal - no external oscillator components required (M41T62)
功能框图
M41T65 订购信息
订购型号 产品状态 美金价格 数量 封装 包装形式 温度范围 材料声明
M41T65Q6E Active     VFQFPN 16 3x3x0.9 Tube -40 °C-85°C M41T65Q6E
M41T65Q6F Active     VFQFPN 16 3x3x0.9 Tape And Reel -40 °C-85°C M41T65Q6F
DATASHEET
描述 版本 大小
M41T65 : DS3840: Serial real-time clocks (RTCs) with alarm 19 873KB
APPLICATION NOTES
描述 版本 大小
AN922: Using a Super Cap to back up the M41T56, M41T00, M41T11, M41T65, M41T94, and M41ST84W (16-pin) 2 85KB
AN1012: Predicting the battery life and data retention period of NVRAMs and serial RTCs 4 440KB
AN1572: Power-down time-stamp function in serial real-time clocks (RTCs) 2 172KB
AN1216: Implementing a periodic alarm with TIMEKEEPER® 1 55KB
AN934: How to use the digital calibration feature in TIMEKEEPER® and serial real-time clock (RTC) products 4 124KB
AN1011: Battery technology used in NVRAM and real-time clock (RTC) products from ST 4 249KB
AN3060: Applications guide for serial real-time clocks 1 355KB
USER MANUALS
描述 版本 大小
UM0276 : STFPC311 LED evaluation board hardware description and user manual 2 503KB