M41T83:Serial I²C bus real-time clock (RTC) with battery switchover

The M41T8x are low-power serial I2C real-time clocks (RTCs) with a built-in 32.768 kHz oscillator (external crystal-controlled for the QFN16 and SO8 packages, embedded crystal for the SOX18 package). Eight bytes of the register map (see Table 2 on page 23) 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 two-line, bidirectional I2C interface. The built-in address register is incremented automatically after each WRITE or READ data byte. The M41T8x 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, two alarm interrupts, 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 M41T83 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. The M41T82 is available only in an SO8 package.

Key Features

  • Ultra-low battery supply current of 365 nA
  • Factory-calibrated accuracy of ±5 ppm typical 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)
    • M41T83S: VCC = 3.00 V to 5.50 V
    • M41T83R: VCC = 2.70 V to 5.50 V
    • M41T83Z: VCC = 2.38 V to 5.50 V
  • Serial interface supports I2 C bus (400 kHz protocol)
  • Programmable alarm with interrupt function (valid even during battery backup mode)
  • Optional 2nd programmable alarm available
  • Square wave output defaults to 32 KHz on power-up (M41T83 only)
  • 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
    • a 16-lead QFN (M41T83)
    • an 8-lead SOIC (M41T82) or
    • an 18-lead embedded crystal SOIC (M41T83)
  • RoHS compliance: lead-free components are compliant with the RoHS directive
Product Specifications
DescriptionVersionSize
DS4858: Serial I2C bus real-time clock (RTC) with battery switchover18.02 MB
Application Notes
DescriptionVersionSize
AN3060: Applications guide for serial real-time clocks (RTCs)3.0878 KB
AN1011: Battery technology used in NVRAM and real-time clock (RTC) products from ST4.0248 KB
AN2678: Extremely accurate timekeeping over temperature using adaptive calibration2.1214 KB
AN934: How to use the digital calibration feature in TIMEKEEPER® and serial real-time clock (RTC) products4.1123 KB
AN1216: Implementing a periodic alarm with TIMEKEEPER® and serial real-time clocks (RTCs)2.0192 KB
AN4641: Integrating TIMEKEEPER® and real-time clock supervisor functions1.0479 KB
AN923: Managing century information using serial real-time clocks and TIMEKEEPER® NVRAMs4.0142 KB
AN1572: Power-down time-stamp function in serial real-time clocks (RTCs)2.0171 KB
AN1336: Power-fail comparator for NVRAM supervisory devices2.0127 KB
AN1012: Predicting the battery life and data retention period of NVRAMs and serial RTCs4.1439 KB
AN2971: Using the typical temperature characteristics of 32 KHz crystal to compensate the M41T83 and M41T93 serial real-time clocks1.2401 KB
HW Model & CAD Libraries
DescriptionVersionSize
M41T83 IBIS Model1.016 KB
Brochures
DescriptionVersionSize
Serial real-time clock ICs1.0827 KB
Smart grid distribution and smart meters - Energy-efficient solutions2.01 MB
Clocks and Timers Software
Part NumberManufacturerDescription
STSW-SRTC001STI2C code for Serial RTC
STSW-SRTC002STSPI code -Serial RTC
Sample & Buy
Part NumberPackagePacking TypeOperating Temperature (°C) (min)Operating Temperature (°C) (max)Unit Price (US$) *QuantityNVRAM size (B)ECCN (EU)ECCN (US)Country of Origin
M41T83SMY6FSO18 with embedded crystalTape And Reel-40851.965100012NECEAR99MALAYSIA
M41T83ZMY6FSO18 with embedded crystalTape And Reel-40851.965100012NECEAR99MALAYSIA
M41T83RQA6FVFQFPN 16 4x4x1.0Tape And Reel-40851.318100012NECEAR99MALAYSIA
M41T83ZQA6FVFQFPN 16 4x4x1.0Tape And Reel-40851.318100012NECEAR99MALAYSIA
M41T83SQA6FVFQFPN 16 4x4x1.0Tape And Reel-40851.318100012NECEAR99MALAYSIA
M41T83RMY6FSO18 with embedded crystalTape And Reel-40851.965100012NECEAR99MALAYSIA
Quality & Reliability
Part NumberPackageGradeRoHS Compliance GradeMaterial Declaration**
M41T83SMY6FSO18 with embedded crystalIndustrialEcopack1md_2o-wspc-so18-wspc-.30-wspc-with-wspc-embedded-wspc-crystal_as2ob6la83s-wspc-(m41t83smy6f)_signed.pdf
md_2o-wspc-so18-wspc-.30-wspc-with-wspc-embedded-wspc-crystal_as2ob6la83s-wspc-(m41t83smy6f).xml
M41T83ZMY6FSO18 with embedded crystalIndustrialEcopack1md_2o-wspc-so18-wspc-.30-wspc-with-wspc-embedded-wspc-crystal_gzmyb6la83z-wspc-(m41t83zmy6f).pdf
md_2o-wspc-so18-wspc-.xml
M41T83RQA6FVFQFPN 16 4x4x1.0IndustrialEcopack2md_qa-wspc-vfqfpn16-wspc-4x4x1_ezqa-wspc-b6la83r.pdf
md_qa-wspc-vfqfpn16-wspc-4x4x1_ezqa-wspc-b6la83r.xml
M41T83ZQA6FVFQFPN 16 4x4x1.0IndustrialEcopack2md_qa-wspc-vfqfpn-wspc-16-wspc-4x4-wspc-x1.0-wspc-pitch-wspc-0.65_ezqa-wspc-b6la83z.pdf
md_qa-wspc-vfqfpn-wspc-16-wspc-4x4-wspc-x1.xml
M41T83SQA6FVFQFPN 16 4x4x1.0IndustrialEcopack2md_x8-wspc-vfqfpn-wspc-16-wspc-4x4x1.0-wspc-pitch-wspc-0.65_ezqab6la83s.pdf
md_x8-wspc-vfqfpn-wspc-16-wspc-4x4x1.xml
M41T83RMY6FSO18 with embedded crystalIndustrialEcopack1
带有电池自动切换功能的串行 I2C 总线实时时钟(RTC) M41T83
circuit_diagram_12578_thumbnail.png M41T83
串行实时时钟(RTC)应用指南 M41T60
ST NVRAM 和实时时钟(RTC)产品中使用的电池技术 M4Z28-BR00SH
使用自适应校准实现不同温度下的极高计时精度 M41T83
How to use the digital calibration feature in TIMEKEEPER® and serial real-time clock (RTC) products M41T60
Implementing a periodic alarm with TIMEKEEPER® and serial real-time clocks (RTCs) M41T94
集成TIMEKEEPER® 与实时时钟监控器功能 M41T60
Managing century information using serial real-time clocks and TIMEKEEPER® NVRAMs M41T60
串行实时时钟(RTC)的掉电时间戳功能 M41T60
Power-fail comparator for NVRAM supervisory devices M41T60
预测NVRAM 和串行RTC 的电池寿命和数据保存期限 M4Z28-BR00SH
使用32 KHz 晶振的典型温度特性补偿M41T83 和M41T93 串行实时时钟 M41T83
Using the typical temperature characteristics of 32 KHz crystal to compensate the M41T83 and M41T93 serial real-time clocks M41T83
Predicting the battery life and data retention period of NVRAMs and serial RTCs M4T28-BR12SH
STEVAL-ISA062V1: 6 W, wide-range dual and single output SMPS demonstration board based on the VIPer17 STEVAL-ISA062V1
md_2o-wspc-so18-wspc-.30-wspc-with-wspc-embedded-wspc-crystal_as2ob6la83s-wspc-(m41t83smy6f)_signed.pdf M41T83
md_2o-wspc-so18-wspc-.30-wspc-with-wspc-embedded-wspc-crystal_as2ob6la83s-wspc-(m41t83smy6f).xml M41T83
md_2o-wspc-so18-wspc-.30-wspc-with-wspc-embedded-wspc-crystal_gzmyb6la83z-wspc-(m41t83zmy6f).pdf M41T83
md_2o-wspc-so18-wspc-.xml M41T83
md_qa-wspc-vfqfpn16-wspc-4x4x1_ezqa-wspc-b6la83r.pdf M41T83
md_qa-wspc-vfqfpn16-wspc-4x4x1_ezqa-wspc-b6la83r.xml M41T83
md_qa-wspc-vfqfpn-wspc-16-wspc-4x4-wspc-x1.0-wspc-pitch-wspc-0.65_ezqa-wspc-b6la83z.pdf M41T83
md_qa-wspc-vfqfpn-wspc-16-wspc-4x4-wspc-x1.xml M41T83
md_x8-wspc-vfqfpn-wspc-16-wspc-4x4x1.0-wspc-pitch-wspc-0.65_ezqab6la83s.pdf M41T83
md_x8-wspc-vfqfpn-wspc-16-wspc-4x4x1.xml LNBH29