What the DS1388Z-33+T&R brings to a timekeeping design
The DS1388Z-33+T&R is a serial real-time clock (RTC) with a full clock/calendar function — tracks seconds, minutes, hours, day, date, month, and year with leap-year compensation through 2099. The I²C 2-wire serial interface keeps the bus wiring minimal: SDA and SCL plus the interrupt output, all on a standard 8-SOIC footprint. Beyond basic timekeeping, this part integrates an EEPROM (512 bytes), a power-fail supervisor, a trickle-charger for backup battery management, and a watchdog timer — all in one 8-pin package. That consolidation saves board space and reduces the component count in a metering, data-logging, or alarm panel design.
Supply rails and timekeeping current — the power budget
Timekeeping current maxes at 150 µA across the full supply range — this is the current drawn from the backup source when the main rail is absent. For a 225 mAh CR2032 coin cell, that works out to roughly 1500 hours of backup at the worst-case draw; actual battery life will be longer at the typical current.