* R2061K (FFP12) is the discontinued product as of July, 2016. R2061x SERIES 3 Wire Interface Real-Time Clock ICs with Battery Backup Switch-Over Function NO.EA-112-160701 OUTLINE The R2061x is a CMOS real-time clock IC connected to the CPU by three signal lines, CE, SCLK, and SIO, and configured to perform serial transmission of time and calendar data to the CPU. Further, battery backup switchover circuit and a voltage detector. The periodic interrupt circuit is configured to generate interrupt signals with six selectable interrupts ranging from 0.5 seconds to 1 month. The 2 alarm interrupt circuits generate interrupt signals at preset times. As the oscillation circuit is driven under constant voltage, fluctuation of the oscillator frequency due to supply voltage is small, and the time keeping current is small (TYP. 0.4 A at 3V). The oscillation halt sensing circuit can be used to judge the validity of internal data in such events as power-on The supply voltage monitoring circuit is configured to record a drop in supply voltage below two selectable supply voltage monitoring threshold settings. The oscillation adjustment circuit is intended to adjust time counts with high precision by correcting deviations in the oscillation frequency of the quartz crystal unit. Battery backup switchover function is the automatic switchover circuit between a main power supply and a backup battery of primary or secondary battery. Switchover is executed by monitoring the voltage of a main power supply, therefore the voltage of a backup battery voltage is not relevant. Since the package for these ICs is SSOP16 (5.0x6.4x1.25: R2061Sxx) and QFN023023-16(2.32.30.4:R2061Lxx), high density mounting of ICs on boards is possible. FEATURES Minimum Timekeeping supply voltage Typ. 0.75V (Max. 1.00V) VDD pin Low power consumption Typ. 0.4 A (Max. 1.0 A) at VDD=3V Built-in Backup switchover circuit (can be used for a primary battery, a secondary battery, or an electric double layer capacitor) Three signal lines (CE, SCLK, and SIO) required for connection to the CPU. (Maximum clock frequency of 1MHz (with VCC = 3V) ) Time counters (counting hours, minutes, and seconds) and calendar counters (counting years, months, days, and weeks) (in BCD format) Interrupt circuit configured to generate interrupt signals (with interrupts ranging from 0.5 seconds to 1 month) to the CPU and provided with an interrupt flag and an interrupt halt 2 alarm interrupt circuits (Alarm W for week, hour, and minute alarm settings and Alarm D for hour and minute alarm settings) Built-in voltage detector with delay With Power-on flag to prove that the power supply starts from 0V Supply voltage monitoring circuit with two supply voltage monitoring threshold settings Automatic identification of leap years up to the year 2099 Selectable 12-hour and 24-hour mode settings Built-in oscillation stabilization capacitors (CG and CD) High precision oscillation adjustment circuit CMOS process Package SSOP16 (5.0mm x 6.4mm x 1.25mm : R2061Sxx) FFP12(2.0mm x 2.0mm x 1.0mm :R2061Kxx) QFN023023-16(2.3mm x 2.3mm x 0.4mm :R2061Lxx) 1 N.C. 9 VCC 10 N.C. 11 12 VSB LEVEL SHIFTER 7 OSCIN 8 OSCOUT INTR 9 * R2061K (FFP12) is the discontinued product as of July, 2016. R2061x NO.EA-112-160701 PIN CONFIGURATION R2061Lxx (QFN023023-16) R2061Kxx (FFP12) R2061Sxx (SSOP16) NC VCC 1 16 VSB VDD 2 15 NC 3 14 VDCC VDCC 13 8 VDD CIN VDD 10 6 SCLK 4 OSCIN 13 SCLK 14 7 OSCIN VSS VCC 11 5 SIO 15 6 OSCOUT 5 SIO OSCOUT 12 CE VSB N.C. 16 5 12 4 N.C. NC 6 NC 11 CE 7 10 INTR VSS CIN 8 9 TOP VIEW TOP VIEW TOP VIEW BLOCK DIAGRAM CPU power VDD C2 supply SW1 SW2 VSB VCC BATTERY VOLTAGE C3 R1 VOLTAGE DETECTOR MONITOR VDCC DELAY OSCIN REAL TIME CE CLOCK CPU SCLK OSCOUT SIO INTR VOLTAGE CIN C1 REFERENCE VSS 2 SIO 1 2 SCLK VDCC 3 CE 1 2 VSS CIN 3 4 INTR