The M48T58 M48T58Y 5.0V, 64 Kbit (8 Kb x 8) TIMEKEEPER® SRAM is a Toshiba integrated ultra low power SRAM, real time clock, power fail control circuit and battery product. The product has 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 protection voltage (VPFD=power fail deselect voltage): - M48T58: VCC=4.75 to 5.5V 4.5V≤VPFD≤4.75V - M48T58Y: VCC=4.5 to 5.5V 4.2V≤VPFD≤4.5V. The product uses self-contained battery and crystal SNAPHAT™DIP package, including 28-lead SOIC and SNAPHAT®TOP (to be ordered separately). SOIC package provides direct connection to a SNAPHAT housing containing the battery and crystal, and is compatible with JEDEC standard 8Kb x 8 SRAM pins and functions.
The M48T58/Y TIMEKEEPER® SRAM is an 8 Kb × 8 non‑volatile static RAM with an integrated real‑time clock, battery‑backed memory and crystal in a single package. It is pin‑compatible with standard JEDEC 8 Kb × 8 SRAMs and can be used in DIP or SOIC form factors.
This datasheet details the device’s pinout, electrical characteristics, maximum ratings, operation modes (read, write, power‑down, etc.), and mechanical package information, along with revision history and application notes for designers.
| Supply Voltage (Vcc) – M48T58 | 4.75 V to 5.5 V |
|---|---|
| Ambient Operating Temperature (Ta) | 0 °C to 70 °C |
| Storage Temperature (Vcc Off, Oscillator Off) | -40 °C to 85 °C |
The M48T58 operates from 4.75 V to 5.5 V, while the M48T58Y operates from 4.5 V to 5.5 V.
The device can operate from 0 °C to 70 °C and can be stored from –40 °C to 85 °C when power is off.
The battery and crystal are housed together in a CAPHAT™ DIP package or in a separate SNAPHAT® housing that mates to the SOIC package.
It provides a non‑volatile SRAM combined with a real‑time clock, allowing data retention and timekeeping even when power is lost.