HT1381(LX)

The HT1381 is a serial real-time clock IC featuring seconds, minutes, hours, date, day-of-week, month, and year timekeeping. It provides automatic adjustment for the number of days per month and leap year correction, supports low-power operating mode, and stores corresponding data in dedicated registers, with a 32.768 KHz crystal for clock calibration. To minimize pin count, it interfaces with a microprocessor via a single I/O port using only three lines: (1) RST reset; (2) SCLK serial clock; (3) I/O data — enabling transfer of 1-byte or 8-byte burst data. As a result, the HT1381 offers an exceptionally cost-effective real-time clock solution.

Applications

• Telephone
• Fax
• Portable instruments
• Battery-powered instrumentation

Key features

• Operating voltage: 2.0V~5.5V
• Maximum input serial clock: 500KHz at 2.0V, 2MHz at 5.0V
• Operating current: minimum 400nA at 2.0V, minimum 1μA at 5.0V
• TTL compatible
• Serial I/O transmission
• Two data transfer modes: single-byte transfer, multi-byte transfer (burst mode)
• All registers stored in BCD format
• Package: SOP8