MM58274CN. – NATIONAL SEMICONDUCTOR

The National Semiconductor MM58274CN is a real-time clock (RTC) integrated circuit designed for low-power applications requiring accurate timekeeping. It provides a full calendar and clock with seconds, minutes, hours, day, date, month, and year information. Its primary function is to maintain time even when the main system power is off, relying on an external 32.768 kHz crystal. The MM58274CN provides a serial interface for reading and writing time and control data. Typical use cases include battery-backed timekeeping in embedded systems, data loggers, and consumer electronics. The open-drain output is rated for 10V, 20mA, allowing direct interfacing with various microcontrollers without additional buffering. Housed in a 16-pin DIP through-hole package, it simplifies prototyping and board assembly. Its operating temperature range of 0°C to 70°C makes it suitable for standard indoor environments. A key advantage is its minimal external component requirement, streamlining circuit design and reducing BOM cost.