M48T212Y

M48T212Y M48T212V 5V/3.3V TIMEKEEPER® CONTROLLER s CONVERTS LOW POWER SRAM into NVRAMs YEAR 2000 COMPLIANT (4-Digit Year) BATTERY LOW FLAG INTEGRATED REAL TIME CLOCK, POWER-FAIL CONTROL CIRCUIT, BATTERY and CRYSTAL AUTOMATIC POWER-FAIL CHIP DESELECT and WRITE PROTECTION WATCHDOG TIMER CHOICE of WRITE PROTECT VOLTAGES (VPFD = Power-fail Deselect Voltage): – M48T212Y: 4.2V ≤ VPFD ≤ 4.5V – M48T212V: 2.7V ≤ VPFD ≤ 3.0V s s s SNAPHAT (SH) Battery s 44 1 SOH44 (MH) s s s s MICROPROCESSOR POWER-ON RESET PROGRAMMABLE ALARM OUTPUT ACTIVE in the BATTERY BACKED-UP MODE PACKAGING INCLUDES a 44-LEAD SOIC and SNAPHAT® TOP (to be Ordered Separately) Figure 1. Logic Diagram s VCC VCCSW DESCRIPTION The M48T212Y/V are self-contained devices that include a real time clock (RTC), programmable alarms, a watchdog timer, and two external chip enable outputs which provide control of up to four (two in parallel) external low-power static RAMs. Access to all TIMEKEEPER ® functions and the external RAM is the same as conventional bytewide SRAM. The 16 TIMEKEEPER Registers offer Century, Year, Month, Date, Day, Hour, Minute, Second, Calibration, Alarm, Watchdog, and Flags. Externally attached static RAMs are controlled by the M48T212Y/V via the E1CON and E2CON signals (see Table 4). The 44 pin 330mil 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...