R2045 Series
4-wire Serial Interface Real Time Clock (RTC) Module

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  • Description

    The R2045 is a real-time clock module, built in CMOS real-time clock IC and crystal oscillator, connected to the CPU by four signal lines, CE, SCLK, SI, and SO, and configured to perform serial transmission of time and calendar data to the CPU. The oscillation frequency is adjusted to high precision (0±5ppm: 13 sec. per month at 25°C). 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. 0.48µA 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 32-kHz clock output function (N-channel Open drain output) is intended to output sub-clock pulses for the external microcomputer. The oscillation adjustment circuit is intended to adjust time by correcting deviations in the oscillation frequency of the crystal oscillator.

  • Spec
    Timekeeping Supply Voltage Range 1.15 V to 5.50 V
    Supply Current Typ. 0.48 µA (VDD = 3 V)
    Connection to CPU Four Signal Lines (CE, SCLK, SI, SO)
    Clock Output 32.768 kHz (Nch Open Drain Output Controllable by command)
    Package SOP14
    Built-in Crystal Oscillator Oscillation Frequency Accuracy: 0 ±5 ppm

    Protections / Functions

    ECO Clock Adjust OSC Halt Sensing Supply Voltage Monitoring Circuit Automatic Identification of Leap Years Selectable 12-hour and 24-hour Backup Switch
  • Technical
  • Quality &
    • Refer to the datasheets for the details on the product.
    • The package file or the datasheet includes package dimensions, taping specifications, taping reels dimensions, power dissipations, and recommended land pattern.

Download Datasheet

Functional Description

ECO ECO Function
Clock Adjust Clock Adjust Function
OSC Halt Sensing OSC Halt Sensing Function
Supply Voltage Monitoring Circuit Supply Voltage Monitoring Function
Automatic Identification of Leap Years Automatic Identification of Leap Years
Selectable 12-hour and 24-hour Selectable 12-hour and 24-hour
Built-in VD with Delay Time Built-in VD with Delay Time

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