OVERVIEW
The SM8577B is a CMOS serial-interface type realtime clock IC that operates at 32.768 kHz. It employs a 3-line serial interface to transfer time and date data. It incorporates a supply-voltage detect function to determine data validity/invalidity. It features an output interrupt with 32 kHz or 1 Hz output frequency. It is available in 8-pin SOPs.

FEATURES
■ 2.5 to 5.5 V operating voltage range
■ 1.0 µA at 3.0 V (typ) current consumption
■ 3-line serial interface
■ 1.7 ± 0.3 V supply voltage detection threshold
■ Timer counters for second, minute, hour, day, day of the week, month, and year
■ Automatic leap-year calendar adjustment
■ 32.768 kHz and 1 Hz output interrupt selectable
■ Crystal oscillator circuit built-in (CD built-in)
■ 24-hour time mode
■ 8-pin SOP