HT1381M/TR

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. 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. Has several registers to store the corresponding information with 8 - bit data format. A 32768Hz crystal is required to provide the correct timing. Uses a serial I/O transmission method to interface with a microprocessor. Only three wires are required: (1) REST (2) SCLK and (3) I/O. Data can be delivered 1 byte at a time or in a burst of up to 8 bytes.

Applications

• Microcomputer serial clock
• Clock and Calendar

Key features

• Operating voltage: 2.0V ~ 5.5V
• Maximum input serial clock: 500kHz at VDD = 2V, 2MHz at VDD = 5V
• Operating current: less than 1μA at 2V, less than 1.2μA at 5V
• TTL compatible: VH: 2.0V ~ VDD + 0.3V at VDD = 5V; VL: 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
• HT1380: 8 - pin DIP package; HT1381: 8 - pin SOP package