DS1391U-3+

The DS1391U-3+ is a low voltage SPI real time clock (RTC) with trickle charger in 10 pin µSOP package. It has typical operating voltage of 3V. This clock/calendar provides hundredths of seconds, seconds, minutes, hours, day, date, month and year information. The date at the end of the month is automatically adjusted for months with fewer than 31 days including leap year compensation valid up to 2100. The clock operates in either 24hour or 12hour format with an AM/PM indicator. One programmable time of day alarm is provided. A temperature compensated voltage reference monitors the status of VCC and automatically disables bus interface and switches to backup supply if a power failure is detected. The DS1391 replaces SQW/complementary INT pin with complementary RST output/debounced input. The device is programmed serially through SPI compatible bidirectional bus. The DS1391 is used in GPS/telematics devices, embedded time stamping applications.

• Supply voltage range from 2.7V to 3.3V
• Operating temperature range from -40°C to 85°C
• Power fail detect and switch circuitry
• SPI supports modes 1 and 3
• SCLK frequency of 4MHz ( 2.7V ≤ VCC ≤ 5.5V)
• UL recognized
• VCC active supply current of 2mA and VCC standby current of 80μA
• Time keeping current of 500nA

Applications

Clock & Timing, Medical, Portable Devices

Notes

ADI products are only authorized (and sold) for use by the customer and are not to be resold or otherwise passed on to any third party