Renesas real-time clocks (RTC IC) are ultra-low-power clock/date devices with programmable time-of-day alarms and programmable square-wave outputs. These devices offer high noise immunity, low current consumption, 12/24 hour mode of operation, auto-correction for leap year, and programmable square wave output, making them ideal for a wide range of design applications.
Renesas' real-time clock ICs count seconds, minutes, hours, day, date, month, and year with leap-year compensation valid up to 2100. The devices feature normal and fast-mode I2C interfaces, two time-of-day alarms, an oscillator stop flag, programmable square-wave outputs that default to 32kHz on power-up, and operating voltages ranging from 1.8V to 5.5V. The Renesas 1338 real-time clock IC includes a 56-Byte battery-backed non-volatile RAM for data storage.
About Real-Time Clocks (RTC IC)
A real-time clock IC (RTC IC) is an integrated circuit that keeps track of the current time and date, typically counting seconds, minutes, hours, day, month, and year with leap-year compensation. Although the term often refers to the devices in personal computers, servers and embedded systems, real-time clock ICs are present in almost any electronic device which needs to keep accurate time. Most of Renesas' real-time clocks use an external crystal oscillator, but some contain an integrated oscillator to simplify the circuit and reduce the bill-of-materials (BOM). Most often, the oscillator's frequency is 32.768kHz, or, exactly 2^15 cycles per second; making it a convenient rate to use with binary counter circuits.