The DS1340 is a real-time clock (RTC)/calendar that is pin compatible and functionally equivalent to the ST M41T00, including the software clock calibration. The device additionally provides trickle-charge capability on the VBACKUP pin, 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 provides seconds, minutes, hours, day, date, month, and year information. A built-in power-sense circuit detects power failures and automatically switches to the backup supply. The device is programmed serially through an I²C bidirectional bus.
Key Features
Applications/Uses
Enhanced Second Source for the ST M41T00
Available in a Surface-Mount Package with an Integrated Crystal (DS1340C)
Fast (400kHz) I²C Interface
Software Clock Calibration
RTC Counts Seconds, Minutes, Hours, Day, Date, Month, and Year
Automatic Power-Fail Detect and Switch Circuitry
Trickle-Charge Capability
Low Timekeeping Voltage Down to 1.3V
Three Operating Voltage Ranges (1.8V, 3V, and 3.3V)
Download
E-Mail