OUTLINE

The RS5C317A/B are CMOS type real-time clock ICs which are connected to the CPU via three signal lines and capable of serial transmission of clock and calendar data to the CPU.

The RS5C317A/B can generate various periodic interrupt clock pulses lasting for long period (one month), further alarm interrupt can be made by days of the week, hours, and minutes. The function of 32kHz clock output and timer counter for watch-dog-timer are also include. Driving an oscillation circuit at constant voltage, the circuit undergoes few voltage fluctuations and consequently realizes low current consumption (0.6µA at 3V). It also provides an oscillator halt sensing function for application to data validity at power-on and other occasions. Integrated into a compact and thin 14pin SSOP (0.65mm pitch), the RS5C317A/B are the optimum choice for equipment requiring small size and low power consumption.

The RS5C317A and the RS5C317B reads/writes data at falling and rising edge of serial clock respectively.

FEATURES

• Time keeping voltage 1.6V to 6.0V

• Lowest supply current 0.6µA TYP. (1.5µA MAX.) at 3V

• Connection to the CPU via only three pins: CE, SCLK/SCLK and SIO for addressing and data read/write

• A clock counter (counting hours, minutes, and seconds) and a calendar counter (counting leap years, years, months, days, and days of the week) in BCD code

• Periodic interrupt pulses to the CPU with cycles ranging from one month to 1/1024Hz, with interrupt flags and interrupt halt

• Alarm interrupt (days of the week, hours, minutes)

• Counter for timer with internal clock

• Oscillator halt sensing to judge internal data validity

• 32kHz clock output with enable switch

• Second digit adjustment by ±30 seconds

• 12-hour or 24-hour time display selectable

• Automatic leap year recognition up to the year 2099

• CMOS logic

• Package: 14pin SSOP (0.65mm pitch)