ISL12020/ISL12020M pdf datashe

Low Power RTC with VDD Battery Backed SRAM and Integrated ±5ppm Temperature
Compensation and Auto Day Light Saving
The ISL12020M device is a low power real time clock (RTC)
with an embedded temperature sensor for oscillator
compensation, clock/calendar, power fail, low battery
monitor, brownout indicator, single periodic or polled alarms,
intelligent battery backup switching, and 128 bytes of
battery-backed user SRAM. The device is offered in a 20
lead DFN module that contains the RTC and an embedded
32.768kHz quartz crystal. The combined device is trimmed
to provide less than ±5ppm drift over -40°C to +85°C
temperature range.
The RTC tracks time with separate registers for hours,
minutes, and seconds. The device has calendar registers for
date, month, year and day of the week. The calendar is
accurate through 2099, with automatic leap year correction.
Daylight Savings time adjustment is done automatically,
using parameters entered by the user. Power fail and battery
monitors offer user-selectable trip levels. A time stamp
function records the time and date of switchover from VDD to
VBAT power, and also from VBAT to VDD power.