5 V, 64 Kbit (8 Kb x 8) TIMEKEEPER® SRAM

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  • The M48T08/18/08Y TIMEKEEPER®RAM is an 8 K x 8 non-volatile static RAM and real-time clock which is pin and function compatible with the DS1643. The monolithic chip is available in two special packages to provide a highly integrated battery-backed memory and real-time clock solution.

    The M48T08/18/08Y is a non-volatile pin and function equivalent to any JEDEC standard 8 K x 8 SRAM. It also easily fits into many ROM, EPROM, and EEPROM sockets, providing the non-volatility of PROMs without any requirement for special WRITE timing or limitations on the number of WRITEs that can be performed.
    The 28-pin, 600 mil DIP CAPHAT™ houses the M48T08/18/08Y silicon with a quartz crystal and a long-life lithium button cell in a single package.
    The 28-pin, 330 mil SOIC provides sockets with gold-plated contacts at both ends for direct connection to a separate SNAPHAT® housing containing the battery and crystal. The unique design allows the SNAPHAT®battery package to be mounted on top of the SOIC package after the completion of the surface mount process. Insertion of the SNAPHAT®housing after reflow prevents potential battery and crystal damage due to the high temperatures required for device surface-mounting. The SNAPHAT®housing is keyed to prevent reverse insertion.
    The SOIC and battery/crystal packages are shipped separately in plastic anti-static tubes or in tape & reel form. For the 28-lead SOIC, the battery/crystal package (e.g., SNAPHAT®) part number is “M4T28-BR12SH” or “M4T32-BR12SH”.

    Key Features

    • Integrated ultra low power SRAM, real-time clock, power-fail control circuit, and battery
    • BYTEWIDERAM-like clock access
    • BCD coded year, month, day, date, hours, minutes, and seconds
    • Typical clock accuracy of ±1 minute a month, at 25 °C
    • Automatic power-fail chip deselect and WRITE protection
    • WRITE protect VPFD= power-fail deselect voltage):
      • M48T08: VCC= 4.75 to 5.5 V; 4.5 V ≤ VPFD≤ 4.75 V
      • M48T18/T08Y: VCC= 4.5 to 5.5 V; 4.2 V ≤ VPFD≤ 4.5 V
    • Software controlled clock calibration for high accuracy applications
    • Self-contained battery and crystal in the CAPHATDIP package
    • Packaging includes a 28-lead SOIC and SNAPHAT® top (to be ordered separately)
    • SOIC package provides direct connection for a snaphat top which contains the battery and crystal
    • Pin and function compatible with DS1643 and JEDEC standard 8 K x 8 SRAMs
    • RoHS compliant
      • Lead-free second level interconnect

Circuit Diagram

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M48T18-100PC1 PDIP 28 .7 Tube
Active
10000 EAR99 MALAYSIA Check Availability

Distributor availability ofM48T18-100PC1

Distributor Name
Region Stock Min. Order Third party link
DIGIKEY WORLDWIDE 69 1 Order Now
RS COMPONENTS EUROPE 712 1 Order Now
AVNET AMERICA 708 0 Order Now
ARROW EUROPE 39 0 Order Now
Newark Element14 AMERICA 14 0 Order Now
MOUSER WORLDWIDE 873 1 Order Now
Farnell Element14 EUROPE 118 1 Order Now

Distributor reported inventory date: 2019-09-20

Distributor Name

DIGIKEY

Stock

69

Min.Order

1

Region

WORLDWIDE Order Now

RS COMPONENTS

Stock

712

Min.Order

1

Region

EUROPE Order Now

AVNET

Stock

708

Min.Order

0

Region

AMERICA Order Now

ARROW

Stock

39

Min.Order

0

Region

EUROPE Order Now

Newark Element14

Stock

14

Min.Order

0

Region

AMERICA Order Now

MOUSER

Stock

873

Min.Order

1

Region

WORLDWIDE Order Now

Farnell Element14

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118

Min.Order

1

Region

EUROPE Order Now

Distributor reported inventory date: 2019-09-20

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M48T18-150PC1 PDIP 28 .7 Tube
Active
- EAR99 MALAYSIA Check Availability

Distributor availability ofM48T18-150PC1

Distributor Name
Region Stock Min. Order Third party link
DIGIKEY WORLDWIDE 339 1 Order Now
RS COMPONENTS EUROPE 242 1 Order Now
AVNET AMERICA 8 0 Order Now
FUTURE WORLDWIDE 168 12 Order Now
ARROW EUROPE 252 0 Order Now
MOUSER WORLDWIDE 229 1 Order Now
Farnell Element14 EUROPE 278 1 Order Now

Distributor reported inventory date: 2019-09-20

Distributor Name

DIGIKEY

Stock

339

Min.Order

1

Region

WORLDWIDE Order Now

RS COMPONENTS

Stock

242

Min.Order

1

Region

EUROPE Order Now

AVNET

Stock

8

Min.Order

0

Region

AMERICA Order Now

FUTURE

Stock

168

Min.Order

12

Region

WORLDWIDE Order Now

ARROW

Stock

252

Min.Order

0

Region

EUROPE Order Now

MOUSER

Stock

229

Min.Order

1

Region

WORLDWIDE Order Now

Farnell Element14

Stock

278

Min.Order

1

Region

EUROPE Order Now

Distributor reported inventory date: 2019-09-20

Buy now

M48T18-100PC1

Package

PDIP 28 .7

Packing Type

Tube

Distributor availability ofM48T18-100PC1

Distributor Name
Region Stock Min. Order Third party link
DIGIKEY WORLDWIDE 69 1 Order Now
RS COMPONENTS EUROPE 712 1 Order Now
AVNET AMERICA 708 0 Order Now
ARROW EUROPE 39 0 Order Now
Newark Element14 AMERICA 14 0 Order Now
MOUSER WORLDWIDE 873 1 Order Now
Farnell Element14 EUROPE 118 1 Order Now

Distributor reported inventory date: 2019-09-20

Distributor Name

DIGIKEY

Stock

69

Min.Order

1

Region

WORLDWIDE Order Now

RS COMPONENTS

Stock

712

Min.Order

1

Region

EUROPE Order Now

AVNET

Stock

708

Min.Order

0

Region

AMERICA Order Now

ARROW

Stock

39

Min.Order

0

Region

EUROPE Order Now

Newark Element14

Stock

14

Min.Order

0

Region

AMERICA Order Now

MOUSER

Stock

873

Min.Order

1

Region

WORLDWIDE Order Now

Farnell Element14

Stock

118

Min.Order

1

Region

EUROPE Order Now

Distributor reported inventory date: 2019-09-20

Marketing Status

Active

Quantity

10000

ECCN (US)

EAR99

Country of Origin

MALAYSIA

M48T18-150PC1

Package

PDIP 28 .7

Packing Type

Tube

Distributor availability ofM48T18-150PC1

Distributor Name
Region Stock Min. Order Third party link
DIGIKEY WORLDWIDE 339 1 Order Now
RS COMPONENTS EUROPE 242 1 Order Now
AVNET AMERICA 8 0 Order Now
FUTURE WORLDWIDE 168 12 Order Now
ARROW EUROPE 252 0 Order Now
MOUSER WORLDWIDE 229 1 Order Now
Farnell Element14 EUROPE 278 1 Order Now

Distributor reported inventory date: 2019-09-20

Distributor Name

DIGIKEY

Stock

339

Min.Order

1

Region

WORLDWIDE Order Now

RS COMPONENTS

Stock

242

Min.Order

1

Region

EUROPE Order Now

AVNET

Stock

8

Min.Order

0

Region

AMERICA Order Now

FUTURE

Stock

168

Min.Order

12

Region

WORLDWIDE Order Now

ARROW

Stock

252

Min.Order

0

Region

EUROPE Order Now

MOUSER

Stock

229

Min.Order

1

Region

WORLDWIDE Order Now

Farnell Element14

Stock

278

Min.Order

1

Region

EUROPE Order Now

Distributor reported inventory date: 2019-09-20

Marketing Status

Active

Quantity

-

ECCN (US)

EAR99

Country of Origin

MALAYSIA

(*) 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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00 Files selected for download

Technical Documentation

    • Description Version Size Action
      DS0494
      5 V, 64 Kbit (8 Kb x 8) TIMEKEEPER® SRAM
      11.1
      492.02 KB
      PDF
      DS0494

      5 V, 64 Kbit (8 Kb x 8) TIMEKEEPER® SRAM

    • Description Version Size Action
      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
      AN923
      Managing century information using serial real-time clocks and TIMEKEEPER® NVRAMs
      4.0
      142.23 KB
      PDF
      AN1009
      Negative undershoot NVRAM data corruption
      2.0
      82.05 KB
      PDF
      AN1012
      Predicting the battery life and data retention period of NVRAMs and serial RTCs
      4.1
      439.45 KB
      PDF
      AN925
      Time update in ST's TIMEKEEPER® devices
      2.0
      119.68 KB
      PDF
      AN968
      VMEbus TIMEKEEPER® requirements
      2.0
      94.96 KB
      PDF
      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

      AN923

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

      AN1009

      Negative undershoot NVRAM data corruption

      AN1012

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

      AN925

      Time update in ST's TIMEKEEPER® devices

      AN968

      VMEbus TIMEKEEPER® requirements

HW Model, CAD Libraries & SVD

    • Description Version Size Action
      Ibis model 1.0
      15.62 KB
      ZIP
      Ibis model 1.0
      15.61 KB
      ZIP

      Ibis model

      Ibis model

Quality & Reliability

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

      Products Underwriter Laboratories (UL) Information

      Products Underwriter Laboratories (UL) Information

Part Number Marketing Status Package Grade RoHS Compliance Grade Material Declaration**
M48T18-100PC1
Active
PDIP 28 .7 Industrial Ecopack1
M48T18-150PC1
Active
PDIP 28 .7 Industrial Ecopack1

M48T18-100PC1

Package:

PDIP 28 .7

Material Declaration**:

PDF XML

Marketing Status

Active

Package

PDIP 28 .7

Grade

Industrial

RoHS Compliance Grade

Ecopack1

M48T18-150PC1

Package:

PDIP 28 .7

Material Declaration**:

PDF XML

Marketing Status

Active

Package

PDIP 28 .7

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.