If you want to better understand the DS3231 datasheet, then you have come to the right place. The DS3231 is a real-time clock (RTC) that can be used for many applications (datasheet lists servers, telematics, utility power meters, and GPS as some examples). Here I go over the main highlights of the DS3231 in terms of functionality and electrical specs, provide link to full datasheet, and provide a link to a post to quickly see more examples on the DS3231 Real Time Clock.
Main specifications from the DS3231 datasheet
- RTC counts seconds, minutes, hours, date of month, month, day of week, and year (with leap-year compensation).
- Fast (400kHz) I2C interface.
- Battery backup for continuous timekeeping (onboard coin cell battery keeps the RTC running).
- The RTC has an accuracy of ∓2ppm, meaning a drift of 2 seconds for every 1 million seconds, equivalent to a drift of 1 minute per year (not bad at all!).
- This is when operating between 0 degrees Celsius and 40 degrees Celsius (or 32 degrees Fahrenheit and 104 degrees Fahrenheit).
- Supply voltage: 2.3V – 5.5V (typical: 3.3V).
- Active supply current: 200 – 300 μA
- Standby supply current: 110 – 170 μA
- Active Battery Current: 70 – 150 μA
- Timekeeping Battery Current: 0.84 – 3.5 μA

Full details on DS3231 datasheet
When I look for specifications for the DS3231 RTC, I look at the DS3231 datasheet from the manufacturer Maxim Integrated. Full details can be found on their website: https://datasheets.maximintegrated.com/en/ds/DS3231.pdf
Example project based on use of the DS3231 RTC
Please go to the following link for some examples on projects I have done with the DS3231 RTC: https://www.diyengineers.com/2020/12/24/ds3231-with-arduino/
Examples include:
- Programming the current day of week, date, and time on the RTC
- Showing the current day of week, date, and time in the Arduino IDE serial monitor
- Displaying the date and time on a 1602 LCD
- Having an alarm go off at a specific time for 30 seconds
