Skip to main content Skip to first level navigation

RICOH imagine. change.


Skip to main content First level navigation Menu
Main content


High precision I2C-Bus Real-Time Clock Module


Data Sheet

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.


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)


  • Communication devices (multi function phone, portable phone, PHS or pager)
  • OA devices (fax, portable fax)
  • Computer (desk-top and mobile PC, portable word-processor, PDA, electric note or video game)
  • AV components (portable audio unit, video camera,camera, digital camera or remote controller)
  • Home appliances (rice cooker, electric oven)
  • Other (car navigation system, multi-function watch)

Documents Download

Data Sheet Package Info. Mark Info. Quality Assurance Data
R2025S/D (1.70MB) SOP-14 R2025S Reliability
SON-22 R2025D Reliability

All PDF files are less than 1MB unless otherwise stated.

Inquiry about products

Technical Support

Inquiries (SSL Form)

Inquiry about business

Purchase, Request for Samples and Documents


Sample Online

Online Distributors