The M48T37Y/V TIMEKEEPER®RAM is a 32 Kb x 8 non-volatile static RAM and real-time clock. The monolithic chip is available in a special package which provides a highly integrated battery-backed memory and real-time clock solution.
The 44-lead, 330 mil SOIC package 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/crystal 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 packages are shipped separately in plastic anti-static tubes or in tape & reel form. For the 44-lead SOIC, the battery/crystal package (e.g., SNAPHAT) part number is “M4T28-BR12SH” or “M4T32-BR12SH”.
- Integrated ultra low power SRAM, real-time clock, power-fail control circuit, and battery
- Frequency test output for real-time clock software calibration
- Automatic power-fail chip deselect and WRITE protection
- Watchdog timer
- WRITE protect voltage (VPFD= Power-fail deselect voltage):
- M48T37Y: VCC= 4.5 to 5.5 V 4.2 V ≤ VPFD≤ 4.5 V
- M48T37V: VCC= 3.0 to 3.6 V 2.7 V ≤ VPFD≤ 3.0 V
- Packaging includes a 44-lead SOIC and SNAPHAT®top (to be ordered separately)
- SOIC package provides direct connection for a SNAPHAT®top which contains the battery and crystal
- Microprocessor power-on reset (valid even during battery backup mode)
- Programmable alarm output active in the battery backup mode
- Battery low flag
- RoHS compliant
- Lead-free second level interconnect
(**) 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.