
STMicroelectronics
SUMMARY DESCRIPTION
The M48T59/Y/V TIMEKEEPER® RAM is an 8 Kb x8 non-volatile static RAM and real time clock. The monolithic chip is available in two special packages to provide a highly integrated battery backed-up memory and real time clock solution.
FEATURES SUMMARY
■ 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
■ WRITE PROTECT VOLTAGES
(VPFD = Power-fail Deselect Voltage):
– M48T59: VCC = 4.75 to 5.5V
4.5V ≤ VPFD ≤ 4.75V
– M48T59Y: VCC = 4.5 to 5.5V
4.2V ≤ VPFD ≤ 4.5V
– M48T59V*: VCC = 3.0 to 3.6V
2.7V ≤ VPFD ≤ 3.0V
■ SELF-CONTAINED BATTERY AND
CRYSTAL IN THE CAPHAT™ DIP
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
■ MICROPROCESSOR POWER-ON RESET
(Valid even during battery back-up mode)
■ PROGRAMMABLE ALARM OUTPUT
ACTIVE IN THE BATTERY BACK-UP MODE
■ BATTERY LOW FLAG