M41T82

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

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Product overview

Description

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.
  • All 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 I2C bus (400 kHz protocol)
    • 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 (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

Circuit Diagram

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STMicroelectronics - M41T82

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Quality and Reliability

Part Number Marketing Status Package Grade RoHS Compliance Grade Material Declaration**
M41T82RM6F
Active
SO-8 Industrial Ecopack1
M41T82SM6F
Active
SO-8 Industrial Ecopack1
M41T82ZM6F
Active
SO-8 Industrial Ecopack1

M41T82RM6F

Package:

SO-8

Material Declaration**:

PDF XML

Marketing Status

Active

Package

SO-8

Grade

Industrial

RoHS Compliance Grade

Ecopack1

M41T82SM6F

Package:

SO-8

Material Declaration**:

PDF XML

Marketing Status

Active

Package

SO-8

Grade

Industrial

RoHS Compliance Grade

Ecopack1

M41T82ZM6F

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.

Sample & Buy

Part Number
Order from Distributors
Order from ST
Marketing Status
ECCN (US)
ECCN (EU)
Packing Type
Package
Temperature (°C) Budgetary Price (US$)*/Qty
More info
min
max
M41T82ZM6F No availability of distributors reported, please contact our sales office
Active
EAR99 NEC Tape And Reel SO-8 -40 85
MORE INFO

NVRAM size (B):

7

Country of Origin:

MOROCCO

M41T82RM6F Available at 1 distributors

Distributor availability ofM41T82RM6F

Distributor Name
Region Stock Min. Order Third party link
RS COMPONENTS EUROPE 480 1 Buy from Distributor

Distributor reported inventory date: 2022-05-23

Distributor Name

RS COMPONENTS

Stock

480

Min.Order

1

Distributor reported inventory date: 2022-05-23

Active
EAR99 NEC Tape And Reel SO-8 -40 85
MORE INFO

NVRAM size (B):

7

Country of Origin:

MOROCCO

M41T82SM6F No availability of distributors reported, please contact our sales office
Active
EAR99 NEC Tape And Reel SO-8 -40 85
MORE INFO

NVRAM size (B):

7

Country of Origin:

MOROCCO

M41T82ZM6F

Marketing Status

Active

ECCN (US)

EAR99

Budgetary Price (US$)*/Qty

ECCN (EU)

NEC

Packing Type

Tape And Reel

Package

SO-8

Operating Temperature (°C)

(min)

-40

(max)

85

Budgetary Price (US$)* / Qty

NVRAM size (B)

7

Country of Origin

MOROCCO

M41T82RM6F

Marketing Status

Active

ECCN (US)

EAR99

Budgetary Price (US$)*/Qty

Distributor availability ofM41T82RM6F

Distributor Name
Region Stock Min. Order Third party link
RS COMPONENTS EUROPE 480 1 Buy from Distributor

Distributor reported inventory date: 2022-05-23

Distributor Name

RS COMPONENTS

Stock

480

Min.Order

1

Distributor reported inventory date: 2022-05-23

ECCN (EU)

NEC

Packing Type

Tape And Reel

Package

SO-8

Operating Temperature (°C)

(min)

-40

(max)

85

Budgetary Price (US$)* / Qty

NVRAM size (B)

7

Country of Origin

MOROCCO

M41T82SM6F

Marketing Status

Active

ECCN (US)

EAR99

Budgetary Price (US$)*/Qty

ECCN (EU)

NEC

Packing Type

Tape And Reel

Package

SO-8

Operating Temperature (°C)

(min)

-40

(max)

85

Budgetary Price (US$)* / Qty

NVRAM size (B)

7

Country of Origin

MOROCCO

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