M41T0 Serial SPI bus real-time clock (RTC) with battery switchover

The M41T93 is a low-power serial SPI bus real-time clock with a built-in 32.768 kHz oscillator (external crystal-controlled for the QFN16 package, and embedded crystal for the SOX18 package). Eight bytes of the register map are used for the clock/calendar function and are configured in binary coded decimal (BCD) format. An additional 17 bytes of the register map provide status/control of the two alarms, watchdog, 8-bit counter, and square wave functions. An additional seven bytes are made available as user SRAM.

Addresses and data are transferred serially via a serial SPI bus-compatible interface. The built-in address register is incremented automatically after each WRITE or READ data byte. The M41T93 has a built-in power sense circuit which detects power failures and automatically switches to the battery supply when a power failure occurs. The energy needed to sustain the clock operations can be supplied by a small lithium button battery when a power failure occurs.

Functions available to the user include a non-volatile, time-of-day clock/calendar, alarm interrupt, watchdog timer, programmable 8-bit counter, and square wave outputs. 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 M41T93 is supplied in either a QFN16 or an SOX18, 300 mil SOIC which includes an embedded 32 KHz crystal. The SOX18 package requires only a user-supplied battery to provide non-volatile operation.

技术特性
  • Ultra-low battery supply current of 365 nA
  • Factory calibrated accuracy ±5 ppm guaranteed after 2 reflows (SOX18)
    • Much better accuracies achievable using built-in programmable analog and digital calibration circuits
  • 2.0 V to 5.5 V clock operating voltage
  • Counters for tenths/hundredths of seconds, seconds, minutes, hours, day, date, month, year, and century
  • Automatic switchover and reset output circuitry (fixed reference)
    • M41T93S: VCC= 3.0 V to 5.5 V (2.85 V ≤ VRST≤ 3.00 V)
    • M41T93R: VCC= 2.7 V to 5.5 V (2.55 V ≤ VRST≤ 2.70 V)
    • M41T93Z: VCC= 2.38 V to 5.50 V (2.25 V ≤ VRST≤ 2.38 V)
  • Compatible with SPI bus serial interface (supports SPI mode 0 [CPOL = 0, CPHA = 0])
  • Programmable alarm with interrupt function (valid even during battery backup mode)
  • Optional 2ndprogrammable alarm available
  • Square wave output (defaults to 32 KHz on power-up)
  • RESET (RST) output
  • Watchdog timer
  • Programmable 8-bit counter/timer
  • 7 bytes of battery-backed user SRAM
  • Battery low flag
  • Low operating current of 80 μA
  • Oscillator stop detection
  • Battery or SuperCap™ backup
  • Operating temperature of –40 °C to +85 °C
  • Package options include:
    • a 16-lead QFN or an 18-lead embedded crystal SOIC
  • RoHS compliance: lead-free components are compliant with the RoHS directive
功能框图
M41T0 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
M41T93ZMY6F Active     SO-18 Tape And Reel -40 °C-85°C M41T93ZMY6F
M41T93ZQA6F Active     VFQFPN 16 4x4x1.0 Tape And Reel -40 °C-85°C M41T93ZQA6F
M41T93SQA6F Active     VFQFPN 16 4x4x1.0 Tape And Reel -40 °C-85°C M41T93SQA6F
M41T93RMY6F Active     SO-18 Tape And Reel -40 °C-85°C M41T93RMY6F
M41T93RQA6F Active     VFQFPN 16 4x4x1.0 Tape And Reel -40 °C-85°C M41T93RQA6F
M41T93SMY6F Active     SO-18 Tape And Reel -40 °C-85°C M41T93SMY6F
DATASHEET
描述 版本 大小
M41T0 : DS2166: Serial real-time clock with 44 bytes NVRAM and reset 6 344KB
APPLICATION NOTES
描述 版本 大小
AN922: Using a Super Cap to back up the M41T56, M41T00, M41T11, M41T81, 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
UM0402 : Single-phase multi tariff energy meter 1 588KB