0.6 µA timekeeping current defines the battery budget
The DS1337S+ draws 0.6 µA max in timekeeping mode at 1.3 V to 1.8 V — this is the current that drains the backup cell when the main supply is off. For a 220 mAh coin cell, that works out to roughly 42 years of theoretical shelf life before the battery is depleted, assuming no other load on the rail. The timekeeping circuit switches to the backup supply below the main supply threshold automatically.
I²C interface and 8-SOIC package — board integration
Communication is over a standard I²C, 2-wire serial bus — two pins (SCL, SDA) connect to the host controller. The device tracks time in HH:MM:SS (12/24 hr) and date in YY-MM-DD-dd format, with built-in leap-year compensation through 2099. The square-wave output on the SQW pin can be programmed to 1 Hz, 4.096 kHz, 8.192 kHz, or 32.768 kHz — useful for driving a microcontroller wake-up or a charge pump without an external oscillator.
Active production and compliance
The device is rated for surface-mount assembly on standard 8-SOIC land patterns.