BU9873

Datasheet Real-Time Clock (RTC) series I2C BUS Serial Interface RTC with High-precision Oscillation Adjustment BU9873 Outline The BU9873 is a CMOS real-time clock, which has a built-in interrupt generation function. This product is 2 connected to the CPU via I C interface, and configured to perform serial transmission of time and calendar data to the CPU. A high-precision oscillation adjustment circuit is also integrated, which is capable of adjusting time counts with digital method, and correcting deviations in the oscillation frequency of the crystal oscillator. Important Characteristics ■ ■ ■ ■ ■ ■ Time Keeping Voltage Time Keeping Current 1 (VDD=3V, Ta=+25°C) Time Keeping Current 2 (VDD=3V, Ta=-40°C to +85°C) Power Supply Voltage Access Frequency 1 (VDD=1.8V to 2.5V) Access Frequency 2 (VDD=2.5V to 5.5V) 1.45V to 5.5V 0.4µA (Typ) 1.0µA (Max) 1.8V to 5.5V 100kHz (Max) 400kHz (Max) Features ■ ■ ■ ■ 2 Connected to the CPU via I C Interface Time (Hour ･ Minute ･ Second, Selectable 12-Hour and 24-Hour Mode Setting) Calendar (Year･Month･Day･Week) Periodic Interrupt Function (Output from INTRB, Ranging from 1 Second to 1 Month) Alarm Interrupt Function (Day-of-Week ･ Hour ･ Minute in Setting Format, Output from INTRB) Oscillation Halt Sensing Function 32.768 kHz Clock Output (Output from 32KOUT with Control Pin) ±30 Second Adjustment Function Automatic Leap Year Recognition up to the Year 2099 Built-in Oscillation Stabilizing Capacitors (CG, CD) High-Precision Oscillation Adj...