DS1340 Datasheet – I2C Real Time Clock with Battery Backup

Part Number: DS1340

Function: 2-Wire RTC with trickle charger

Package: SO 8 Pin, SO 16 Pin Type

Manufacturer: Dallas Semiconductor -> Maxim Integrated


DS1340 datasheet


The DS1340 is a real-time clock (RTC)/calendar that is pin compatible and functionally equivalent to the STM41T00, including the software clock calibration. The device additionally provides trickle-charge capability on the VBACKUPpin, a lower timekeeping voltage, and
an oscillator STOP flag. Block access of the register map is identical to the ST device. Two additional registers, which are accessed individually, are required for the trickle charger and flag. The clock/calendar pro
vides seconds, minutes, hours, day, date, month, and year information. A built-in power-sense circuit detects power failures and automatically switches to the back up supply. Reads and writes are inhibited while the clock continues to run. The device is programmed serially through an I2C bidirectional bus.

1. Enhanced Second Source for the ST M41T00
2. Available in a Surface-Mount Package with an
Integrated Crystal (DS1340C)
3. Fast (400kHz) I2C Interface
4. Software Clock Calibration
5. RTC Counts Seconds, Minutes, Hours, Day, Date,
Month, and Year
6. Automatic Power-Fail Detect and Switch Circuitry
7. Trickle-Charge Capability
8. Low Timekeeping Voltage Down to 1.3V
9. Three Operating Voltage Ranges (1.8V, 3V, and 3.3V)
10. Oscillator Stop Flag
11. Available in 8-Pin µSOP or SO Packages
12. Underwriters Laboratories (UL) Recognized

Other data sheets are available within the file:

DS1340C-18#, DS1340C-3#, DS1340C-33#, DS1340U-18+

DS1340 Datasheet PDF Download

DS1340 pdf