The DS1553WP-120+ is a 64KB, non-volatile, timekeeping RAM in 34 pin PWRCP package. This is a full-function, year 2000 compliant (Y2KC) real time clock/calendar (RTC) with an RTC alarm, watchdog timer, power-on reset, battery monitor and 8k x 8 non-volatile static RAM. The RTC registers contain century, year, month, date, day, hours, minutes and seconds data in 24-hour BCD format. Corrections for day of month and leap year are made automatically. It is double-buffered into an internal and external set. User has direct access to external set, clock/calendar updates to external set of registers can be disabled and enabled to allow user to access static data. Assuming the internal oscillator is turned on, the internal set of registers is continuously updated. This occurs regardless of external registers settings to guarantee that accurate RTC information is always maintained.
Supply voltage range is 2.97V to 3.63V
Operating temperature range from 0°C to 70°C
Integrated NV SRAM, RTC, crystal, power-fail control circuit and lithium energy source
Clock registers are accessed identically to static RAM, registers resident in 16 top RAM locations
Totally non-volatile with over 10 years of operation in absence of power
Precision power-on reset
Battery voltage level indicator flag
Power-fail write protection allows for ±10% VCC power-supply tolerance
Li energy source is electrically disconnected to retain freshness until power applied for first time
