Integrated RTC with 32 KB NVSRAM in a PowerCap Module
The DS1554WP-120IND+ is a parallel-interface real-time clock/calendar from Analog Devices that integrates 32 KB of non-volatile SRAM, an alarm, a watchdog timer, and leap-year compensation through 2099 into a single 34-pin PowerCap module.
Timekeeping Current and Supply Rails
Timekeeping draws a maximum of 4 mA at 3.3 V, which sets the budget for the backup battery circuit — a 3 V lithium coin cell maintains the clock and NVSRAM when the main 2.97 V to 3.63 V supply drops out. The parallel interface means the host reads and writes the RTC registers and NVSRAM directly on the processor bus, with no serial protocol translation — useful for legacy 8-bit or 16-bit microcontroller designs where bus timing is already fixed.
Housed in a 34-PowerCap Module, the DS1554WP-120IND+ uses a surface-mount base that accepts a snap-on battery cap — the module's total seated height and footprint match the standard PowerCap layout, so the PCB land pattern is shared across the DS1554 family. The supplier device package is listed as 34-PowerCap Module, confirming the top-side clearance needed for the battery cap in the enclosure.