R2221x R2223x 2-wire Serial Interface Real Time Clock IC NO.EA-227-200525 OUTLINE The R2221x,R2223x is a CMOS real-time clock IC connected to the CPU by two signal lines, SCL, SDA, and configured to perform serial transmission of time and calendar data to the CPU. 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. 0.18A 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 supply voltage monitoring threshold settings. The 32.768kHz clock output function (CMOS output with control pin) is intended to output sub-clock pulses for the external microcomputer. The oscillation adjustment circuit is intended to adjust time counts with high precision by correcting deviations in the oscillation frequency of the crystal oscillator. Since the package for these ICs are TSSOP10G (4.0x2.9x1.0:R2221T,R2223T) or QFN018018-12 (1.8x1.8x0.43: R2221L, R2223L), high density mounting of ICs on boards is possible. FEATURES Minimum Timekeeping supply voltage TYP:0.6 to 5.5v (Worst: 0.9V to 5.5v) VDD pin Ultra low power consumption 0.18A TYP at VDD=3V (0.65A MAX.) Two signal lines (SCL, SDA) required for connection to the CPU. 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) With Power-on flag to prove that the power supply starts from 0V 32-kHz clock output pin (CMOS push-pull output with control pin) Supply voltage monitoring circuit with supply voltage monitoring threshold settings Automatic identification of leap years up to the year 2099 Selectable 12-hour and 24-hour mode settings High precision oscillation adjustment circuit Built-in oscillation stabilization capacitors (CG and CD) Package TSSOP10G (4.0mm x 2.9mm x 1.0mm: R2221T, R2223T) QFN018018-12 (1.8mm x 1.8mm x 0.43mm: R2221L, R2223L) CMOS process 1 7 7 VDD VDD 8 8 NC NC 9 9 32KOUT 32KOUT R2221x, R2223x PIN CONFIGURATION R2221T(TSSOP10G) R2221L(QFN018018-12) 32KOUT 10 VDD 1 10 6 SCL 9 OSCIN SCL OSCIN 2 11 SDA 3 8 OSCOUT 5 SDA OSCOUT 12 4 ECO 4 7 CLKC ECO CLKC VSS 5 6 INTR TOP VIEW TOP VIEW R2223T(TSSOP10G) R2223L(QFN018018-12) 10 32KOUT VDD 1 9 10 6 SCL OSCIN SCL OSCIN 2 3 8 11 SDA OSCOUT SDA 5 OSCOUT 4 7 12 4 INTRB CLKC INTRB CLKC 5 6 VSS INTRA TOP VIEW TOP VIEW BLOCK DIAGRAM ALARM W REGISTER 32KOUT VDD 32kHz COMPARATOR W (MIN,HOUR, WEEK) OUTPUT CLKC CONTROL VOLTAGE ALARM D REGISTER COMPARATOR D DETECT (MIN,HOUR) *2) ECO POWER ON DIVIDER TIME COUNTER OSCIN RESET CORREC DIV OSC (SEC,MIN,HOUR,WEEK,DAY,MONTH,YEAR) VSS -TION OSCOUT SCL ADDRESS OSC ADDRESS I/O REGISTER DETECT DECODER SDA CONTROL INTRA INTR *1) INTERRUPT CONTROL SHIFT REGISTER INTRB *1) As an interrupt pin, the R2221x has INTR, the R2223x has INTRA pin. The R2221x does not have INTRB pin. *2) The R2221x has ECO pin. The R2223x can set ECO mode with the internal resister. 2 1 1 VSS VSS NC NC 2 2 3 3 INTR INTRA