Serial real-time clock (RTC) with 56 bytes NVRAM

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  • The M41T56 is a low-power, serial real-time clock (RTC) with 56 bytes of NVRAM. A built-in 32,768 Hz oscillator (external crystal controlled) and the first 8 bytes of the RAM are used for the clock/calendar function and are configured in binary coded decimal (BCD) format. Addresses and data are transferred serially via a two-line, bidirectional bus. The built-in address register is incremented automatically after each WRITE or READ data byte.

    The M41T56 clock has a built-in power sense circuit which detects power failures and automatically switches to the battery supply during power failures. The energy needed to sustain the RAM and clock operations can be supplied from a small lithium coin cell.
    Typical data retention time is in excess of 10 years with a 50 mAh, 3 V lithium cell. The M41T56 is supplied in an 8-lead plastic SOIC package.

    Key Features

    • Counters for seconds, minutes, hours, day, date, month, years, and century
    • 32 KHz crystal oscillator integrating load capacitance (12.5 pF) providing exceptional oscillator stability and high crystal series resistance operation
    • Serial interface supports I2C bus (100 kHz protocol)
    • Ultra-low battery supply current of 450 nA (typ at 3 V)
    • 5 V ±10% supply voltage
    • Timekeeping down to 2.5 V
    • Automatic power-fail detect and switch circuitry
    • 56 bytes of general purpose RAM
    • Software clock calibration to compensate crystal deviation due to temperature
    • Automatic leap year compensation
    • Operating temperature of –40 °C to 85 °C
    • Available in an 8-lead, 150-mil, plastic SOIC (SO8)
    • RoHS compliant
      • Lead-free second level interconnect

Circuit Diagram

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Part Number
Package
Packing Type
Temperature (°C) Marketing Status
Budgetary Price (US$)*
Quantity
NVRAM size (B)
More info
Order from Distributors
Order from ST
min
max
M41T56M6F SO-8 Tape And Reel -40 85
Active
1.199 1000 56
MORE INFO

ECCN (US):

EAR99

Country of Origin:

MOROCCO

Check Availability

Distributor availability ofM41T56M6F

Distributor Name
Region Stock Min. Order Third party link
DIGIKEY WORLDWIDE 421 1 Order Now
RS COMPONENTS EUROPE 2802 2 Order Now
ARROW EUROPE 25814 0 Order Now
MOUSER WORLDWIDE 14046 1 Order Now

Distributor reported inventory date: 2019-05-20

Distributor Name

DIGIKEY

Stock

421

Min.Order

1

Region

WORLDWIDE Order Now

RS COMPONENTS

Stock

2802

Min.Order

2

Region

EUROPE Order Now

ARROW

Stock

25814

Min.Order

0

Region

EUROPE Order Now

MOUSER

Stock

14046

Min.Order

1

Region

WORLDWIDE Order Now

Distributor reported inventory date: 2019-05-20

Get sample

M41T56M6F

Package

SO-8

Packing Type

Tape And Reel

Unit Price (US$)

1.199*

Distributor availability ofM41T56M6F

Distributor Name
Region Stock Min. Order Third party link
DIGIKEY WORLDWIDE 421 1 Order Now
RS COMPONENTS EUROPE 2802 2 Order Now
ARROW EUROPE 25814 0 Order Now
MOUSER WORLDWIDE 14046 1 Order Now

Distributor reported inventory date: 2019-05-20

Distributor Name

DIGIKEY

Stock

421

Min.Order

1

Region

WORLDWIDE Order Now

RS COMPONENTS

Stock

2802

Min.Order

2

Region

EUROPE Order Now

ARROW

Stock

25814

Min.Order

0

Region

EUROPE Order Now

MOUSER

Stock

14046

Min.Order

1

Region

WORLDWIDE Order Now

Distributor reported inventory date: 2019-05-20

Operating Temperature (°C)

(min)

-40

(max)

85

Marketing Status

Active

Unit Price (US$)

1.199

Quantity

1000

NVRAM size (B)

56

ECCN (US)

EAR99

Country of Origin

MOROCCO

(*) Suggested Resale Price per unit (USD) for BUDGETARY USE ONLY. For quotes, prices in local currency, please contact your local ST Sales Office  or our Distributors

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Embedded Software

00 Files selected for download

Technical Documentation

    • Description Version Size Action
      DS1449
      Serial real-time clock (RTC) with 56 bytes NVRAM
      9.1
      478.23 KB
      PDF
      DS1449

      Serial real-time clock (RTC) with 56 bytes NVRAM

    • Description Version Size Action
      AN3060
      Applications guide for serial real-time clocks (RTCs)
      3.0
      878.56 KB
      PDF
      AN1011
      Battery technology used in NVRAM and real-time clock (RTC) products from ST
      4.0
      248.17 KB
      PDF
      AN934
      How to use the digital calibration feature in TIMEKEEPER® and serial real-time clock (RTC) products
      4.1
      123.42 KB
      PDF
      AN4641
      Integrating TIMEKEEPER® and real-time clock supervisor functions
      1.0
      479.28 KB
      PDF
      AN923
      Managing century information using serial real-time clocks and TIMEKEEPER® NVRAMs
      4.0
      142.23 KB
      PDF
      AN1572
      Power-down time-stamp function in serial real-time clocks (RTCs)
      2.0
      171.31 KB
      PDF
      AN1336
      Power-fail comparator for NVRAM supervisory devices
      2.0
      127.81 KB
      PDF
      AN1012
      Predicting the battery life and data retention period of NVRAMs and serial RTCs
      4.1
      439.45 KB
      PDF
      AN922
      Using a Super Cap to back up the M41T56, M41T00, M41T11, M41T81, M41T94, and M41ST84W (16-pin)
      2.1
      84.5 KB
      PDF
      AN3060

      Applications guide for serial real-time clocks (RTCs)

      AN1011

      Battery technology used in NVRAM and real-time clock (RTC) products from ST

      AN934

      How to use the digital calibration feature in TIMEKEEPER® and serial real-time clock (RTC) products

      AN4641

      Integrating TIMEKEEPER® and real-time clock supervisor functions

      AN923

      Managing century information using serial real-time clocks and TIMEKEEPER® NVRAMs

      AN1572

      Power-down time-stamp function in serial real-time clocks (RTCs)

      AN1336

      Power-fail comparator for NVRAM supervisory devices

      AN1012

      Predicting the battery life and data retention period of NVRAMs and serial RTCs

      AN922

      Using a Super Cap to back up the M41T56, M41T00, M41T11, M41T81, M41T94, and M41ST84W (16-pin)

HW Model, CAD Libraries & SVD

    • Description Version Size Action
      Ibis model 1.0
      8.28 KB
      ZIP

      Ibis model

Publications and Collaterals

    • Description Version Size Action
      Serial real-time clock ICs 1.0
      827.11 KB
      PDF
      Smart grid distribution and smart meters - Energy-efficient solutions 2.0
      1.58 MB
      PDF

      Serial real-time clock ICs

      Smart grid distribution and smart meters - Energy-efficient solutions

Quality & Reliability

    • Description Version Size Action
      Products Underwriter Laboratories (UL) Information 2.1
      543.21 KB
      PDF

      Products Underwriter Laboratories (UL) Information

Part Number Marketing Status Package Grade RoHS Compliance Grade Material Declaration**
M41T56M6F
Active
SO-8 Industrial Ecopack1

M41T56M6F

Package:

SO-8

Material Declaration**:

PDF XML

Marketing Status

Active

Package

SO-8

Grade

Industrial

RoHS Compliance Grade

Ecopack1

(**) The Material Declaration forms available on st.com may be generic documents based on the most commonly used package within a package family. For this reason, they may not be 100% accurate for a specific device. Please contact our sales support for information on specific devices.