Datasheet

Most RTC's use an external 32kHz timing crystal that is used to keep time with low current draw. And that's all well and

good, but those crystals have slight drift, particularly when the temperature changes (the temperature changes the

oscillation frequency very very very slightly but it does add up!) This RTC is in a beefy package because the crystal is

inside

the chip! And right next to the integrated crystal is a temperature sensor. That sensor compensates for the

frequency changes by adding or removing clock ticks so that the timekeeping stays on schedule

This is the finest RTC you can get, and now we have it in a compact, breadboard-friendly breakout. With a coin cell

plugged into the back, you can get years of precision timekeeping, even when main power is lost. Great for

datalogging and clocks, or anything where you need to really know the time.