R2051 系列


  • 概述

    The R2051 is a CMOS real-time clock IC connected to the CPU by two signal lines, SCL and SDA, and configured to perform serial transmission of time and calendar data to the CPU. Further, battery backup switchover circuit and a voltage detector are incorporated. 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 µA 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 32.768 kHz clock output function (CMOS output) 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 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, QFN023023-16 or TSSOP10G, high density mounting of ICs on boards is possible.

  • 规格
    计时电源电压范围 1.0 V to 5.5 V
    最小计时电源电压 Typ. 0.75 V
    电源电流 0.4 µA (VDD = 3 V)
    连接到CPU Two signal Lines (SCL, SDA), I2C-bus Serial Interface, Maximum Clock Frequency: 400 kHz
    时钟输出 32.768 kHz (CMOS Output with Level Shifter)
    封装 QFN023023-16, SSOP16, TSSOP10G
    Backup Switchover Voltage 2.4 V, 2.8 V, 4.0 V


    ECO Clock Adjust OSC Halt Sensing Supply Voltage Monitoring Circuit Automatic Identification of Leap Years Selectable 12-hour and 24-hour Backup Switch
  • 技术资料
  • 品质&封装
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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



特性 +VD
接口 2-wire
min (V)
max (V)