M48T35Y:5 V, 256 Kbit (32 Kb x 8) TIMEKEEPER® SRAM

The M48T35/Y TIMEKEEPER®RAM is a 32 Kb x 8 non-volatile static RAM and real-time clock. The monolithic chip is available in two special packages to provide a highly integrated battery-backed memory and real-time clock solution.

The M48T35/Y is a non-volatile pin and function equivalent to any JEDEC standard 32 Kb 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 CAPHAThouses the M48T35/Y 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”.

Key Features

  • Integrated, ultra low power SRAM, real-time clock, power-fail control circuit and battery
  • BYTEWIDE™ RAM-like clock access
  • BCD coded year, month, day, date, hours, minutes, and seconds
  • Frequency test output for real-time clock
  • Automatic power-fail chip deselect and WRITE protection
  • WRITE protect voltages VPFD = power-fail deselect voltage):
    • M48T35: VCC = 4.75 to 5.5 V; 4.5 V ≤ VPFD ≤ 4.75 V
    • M48T35Y: VCC = 4.5 to 5.5 V; 4.2 V ≤ VPFD ≤ 4.5 V
  • Self-contained battery and crystal in the CAPHAT™ DIP package
  • SOIC package provides direct connection for a SNAPHAT® housing containing the battery and crystal
  • SNAPHAT® housing (battery and crystal) is replaceable
  • Pin and function compatible with JEDEC standard 32 Kb x 8 SRAMs
  • RoHS compliant
    • Lead-free second level interconnect
Product Specifications
DescriptionVersionSize
DS0524: 5 V, 256 Kbit (32 Kb x 8) TIMEKEEPER® SRAM10.1472 KB
Application Notes
DescriptionVersionSize
AN1011: Battery technology used in NVRAM and real-time clock (RTC) products from ST4.0248 KB
AN934: How to use the digital calibration feature in TIMEKEEPER® and serial real-time clock (RTC) products4.1123 KB
AN923: Managing century information using serial real-time clocks and TIMEKEEPER® NVRAMs4.0142 KB
AN1009: Negative undershoot NVRAM data corruption2.082 KB
AN1012: Predicting the battery life and data retention period of NVRAMs and serial RTCs4.1439 KB
AN1019: Second source for SNAPHAT® using a dual footprint2.166 KB
AN925: Time update in ST's TIMEKEEPER® devices2.0119 KB
AN968: VMEbus TIMEKEEPER® requirements2.094 KB
Product Certifications
DescriptionVersionSize
Products Underwriter Laboratories (UL) Information2.1543 KB
Products Underwriter Laboratories (UL) Information2.1162 KB
Sample & Buy
Part NumberPackagePacking TypeQuantityECCN (EU)ECCN (US)Country of Origin
M48T35Y-70PC1PDIP 28 .7Tube1000NECEAR99MALAYSIA
M48T35Y-70MH1FSO-28Tape And Reel1000NECEAR99MALAYSIA
Quality & Reliability
Part NumberPackageGradeRoHS Compliance GradeMaterial Declaration**
M48T35Y-70PC1PDIP 28 .7IndustrialEcopack1md_n9-wspc-pdip-wspc-28-wspc-.7-wspc-zero-wspc-power_hapck6aa5ty-wspc-m48t35y-70pc1).pdf
md_n9-wspc-pdip-wspc-28-wspc-.xml
M48T35Y-70MH1FSO-28IndustrialEcopack1
5 V, 256 Kbit (32 Kb x 8) TIMEKEEPER® SRAM M48T35
circuit_diagram_2611_thumbnail.png M48T35
ST NVRAM 和实时时钟(RTC)产品中使用的电池技术 M4Z28-BR00SH
How to use the digital calibration feature in TIMEKEEPER® and serial real-time clock (RTC) products M41T60
Managing century information using serial real-time clocks and TIMEKEEPER® NVRAMs M41T60
Negative undershoot NVRAM data corruption M48Z58Y
预测NVRAM 和串行RTC 的电池寿命和数据保存期限 M4Z28-BR00SH
Second source for SNAPHAT® using a dual footprint M48T35
Time update in ST's TIMEKEEPER® devices M48T37Y
VMEbus TIMEKEEPER® requirements M48T37Y
Predicting the battery life and data retention period of NVRAMs and serial RTCs M4Z28-BR00SH
Predicting the battery life and data retention period of NVRAMs and serial RTCs M48Z58Y
md_n9-wspc-pdip-wspc-28-wspc-.7-wspc-zero-wspc-power_hapck6aa5ty-wspc-m48t35y-70pc1).pdf M48T35Y
md_n9-wspc-pdip-wspc-28-wspc-.xml M48Z58Y