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.
The Ricoh R2051 is a CMOS real-time clock IC designed for connection to a CPU via two signal lines, SCL and SDA, utilizing an I2C-Bus interface at 400kHz. The device incorporates a battery backup switchover circuit and a voltage detector to ensure continuous timekeeping. It features a periodic interrupt circuit with six selectable ranges and two alarm interrupt circuits for preset times.
| Oscillation Frequency | 32.768 kHz |
|---|---|
| Timekeeping Supply Voltage | 0.75V (Typ.) |
| Timekeeping Current | 0.4uA (Typ.) |
| Operating Temperature | -40 to +85 °C |
| Storage Temperature | -55 to +125 °C |
The maximum operating temperature is +85 °C.
The typical timekeeping current is 0.4uA at 3V.
The maximum input voltage for the SCL and SDA pins is 5.5 volts.