HT1380 Real-Time Clock IC – Serial RTC/Calendar – DIP-8 – Holtek

The Holtek HT1380 is a low-power Real-Time Clock (RTC) and calendar IC designed for precise timekeeping in embedded systems. Packaged in an 8-pin DIP (through-hole) format, it interfaces easily with microcontrollers and is ideal for use in clocks, data loggers, instrumentation, security systems, and other applications requiring accurate date and time tracking.

The HT1380 maintains seconds, minutes, hours, day, date, month, and year information, with automatic leap-year compensation. Its 3-wire serial interface (RST, SCLK, I/O) ensures simple and reliable communication with most microcontrollers. All timekeeping registers are stored in BCD format, simplifying software handling.

With a wide 2.0V to 5.5V operating voltage range and extremely low standby current (typically <100 nA at 5V), the HT1380 is optimized for battery-powered systems. It requires an external 32.768 kHz crystal for stable and accurate timing.

While the HT1380A version has entered End-of-Life (EOL) status, the standard HT1380 remains widely availableand fully supported for commercial use.

Key Specifications:

• Manufacturer: Holtek

• Part Number: HT1380

• Function: Real-Time Clock/Calendar IC

• Interface: 3-wire serial (RST, SCLK, I/O)

• Time Format: BCD-coded registers

• Timekeeping Modes: 12-hour (AM/PM) and 24-hour

• Standby Current: <100 nA typical at 5V

• Operating Voltage: 2.0V to 5.5V

• External Crystal: 32.768 kHz

• Automatic leap-year correction

• Package: DIP-8 (through-hole)

Package Includes:
1 x HT1380 Real-Time Clock IC

Note: Image is for representation purpose only.