HMNR28D(V)

INTEGRATED LOW POWER SRAM, REAL TIME CLOCK, POWER-FAIL CONTROL CIRCUIT, BATTERY and CRYSTAL
BCD CODED YEAR, MONTH, DAY, DATE, HOURS, MINUTES, and SECONDS
AUTOMATIC POWER-FAIL CHIP DESELECT and WRITE PROTECTION VOLTAGES :
   (VPFD = Power-fail Deselect Voltage)
     HMNR28D : V_CC = 4.5 to 5.5V
                            4.2V V_PFD 4.5V
     HMNR28DV: VCC = 3.0 to 3.6V
                            2.7V V_PFD 3.0V
CONVENTIONAL SRAM OPERATION : UNLIMITED WRITE CYCLES
SOFTWARE CONTROLLED CLOCK CALIBRATION FOR HIGH ACCURACY APPLICATIONS
10 YEARS OF DATA RETENTION and CLOCK OPERATION IN THE ABSENCE OF POWER PIN and FUNCTION COMPATIBLE WITH INDUSTRY STANDARD 2K x 8 SRAMS
SELF-CONTAINED BATTERY and CRYSTAL IN DIP PACKAGE

The HMNR28D(V) TIMEKEEPER SRAM is a 2Kb x 8 non-volatile static RAM and real time clock organized as 2,048 words by 8 bits. The special DIP package provides a fully integrated battery back-up memory and real time clock solution. It directly replaces industry standard 2Kbit x 8 SRAMs. It also provides the non-volatility of Flash without any requirement for special WRITE timing or limitations on the number of WRITEs that can be performed.