R2051S01-E2-F Datasheet, PDF (1/49 Pages) RICOH electronics devices division – High precision I2C-Bus Real-Time Clock Module

R2025S/D
High precision I²C-Bus Real-Time Clock Module
NO.EA-225-160706
OUTLINE
The R2025S/D is a real-time clock module, built in CMOS real-time clock IC and crystal oscillator, 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. The oscillation frequency is adjusted to high precision (0±5ppm: 13sec. 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 (CMOS 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.
FEATURES
⋅ Built in 32.768kHz crystal unit, The oscillation frequency is adjusted to high precision (0±5ppm: at 25°C)
⋅ Time keeping voltage 1.15V to 5.5V
⋅ Super low power consumption 0.48µA TYP (1.2µA MAX) at VDD=3V
⋅ I2C-Bus interface (Maximum serial clock frequency: 400KHz at VDD≥1.7V)
⋅ 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)
⋅ 32768Hz Clock CMOS push-pull output with control pin
⋅ With Power-on flag to prove that the power supply starts from 0V
⋅ With Oscillation halt sensing Flag to judge the validity of internal data
⋅ 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
⋅ Oscillation adjustment circuit for correcting temperature frequency deviation or offset deviation
⋅ CMOS process
⋅ Two types of package, SOP14(10.1x7.4x3.1) or SON22(6.1x5.0x1.3)
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