General Description

The HT1380A/HT1381A is a serial timekeeper IC which provides seconds, minutes, hours, day, date, month and year information. The number of days in each month and leap years are automatically adjusted. The HT1380A/HT1381A is designed for low power consumption and can operate in two modes: one is the 12-hour mode with an AM/PM indicator, the other is the 24-hour mode.

Features

• Operating voltage: 2.0V~5.5V

• Maximum input serial clock: 500kHz at VDD=2V, 2MHz at VDD=5V

• Operating current:

– less than 0.5μA at 2V

– less than 0.7μA at 3V

– less than 1.0μA at 5V

• TTL compatible

– VIH: 2.0V~VDD+0.3V at VDD=5V

– VIL: 0.3V~+0.8V at VDD=5V

• Two data transmission modes: single-byte, or burst mode

• Serial I/O transmission

• All registers store BCD format

• HT1380A: 8-pin DIP package

HT1381A: 8-pin SOP package

Applications

• Microcomputer serial clock

• Clock and Calendar