RTC with SPI bus and integrated NVSRAM
The DS1306E+ is a real-time clock (RTC) from Analog Devices that tracks time in HH:MM:SS (12/24 hr) and date in YY-MM-DD-dd format, with a 96-byte NVSRAM for storing configuration or event logs. Communication is over an SPI interface, making it straightforward to hang off a microcontroller's serial bus without dedicated parallel port pins.
On-chip features for standalone operation
Built-in features include a programmable alarm, leap-year compensation, a square-wave output for driving a periodic interrupt or LED, and a trickle-charger that can recharge a backup supercap or battery from the main supply. The 96-byte NVSRAM retains data through power loss as long as the battery voltage stays within the 2 V to 5.5 V range — no external EEPROM needed for small parameter storage.
20-TSSOP surface-mount package
Housed in a 20-TSSOP (4.40 mm width) with a surface-mount footprint, the DS1306E+ fits on compact PCBs where board area is tight. Supplied in tube packaging — the exact ordering code DS1306E+ corresponds to the tube variant; if you need tape-and-reel, verify the suffix before placing the BOM.