Timer ICs / ASSPs

2-wire Realtime Clock S-35399A03

The S-35399A03 is a CMOS 2-wire real-time clock IC which operates with the very low current consumption in the wide range of operation voltage. The operation voltage is 1.3 V to 5.5 V so that the S-35399A03 can be used for various power supplies from main supply to backup battery. Due to the 0.34 μA current consumption and wide range of power supply voltage at time keeping, the S-35399A03 makes the battery life longer. In the system which operates with a backup battery, the included free registers can be used as the function for user’s backup memory. Users always can take back the information in the registers which is stored before power-off the main power supply, after the voltage is restored. The S-35399A03 has the function to correct advance / delay of the clock data speed, in the wide range, which is caused by the crystal oscillation circuit’s frequency deviation. Correcting according to the temperature change by combining this function and a temperature sensor, it is possible to make a high precise clock function which is not affected by the ambient temperature. Moreover, the S-35399A03 has a 24-bit binary up counter. This counter counts up every 60 seconds from power-on so that users are able to grasp the elapsed time from power-on up to 30 years.


Low current consumption
0.34 μA typ. (VDD = 3.0 V, Ta = +25°C)
Wide range of operating voltage
1.3 V to 5.5 V
Built-in clock-correction function
Built-in 24-bit binary up counter
Built-in free user register
2-wire (I2C-bus) CPU interface
Built-in alarm interrupter
Built-in flag generator during detection of low power voltage or at power-on
Auto calendar up to the year 2099, automatic leap year calculation function
Built-in constant voltage circuit
Built-in 32.768 kHz crystal oscillation circuit (built-in Cd, external Cg)
Lead-free (Sn 100%), halogen-free


  • Mobile game device
  • Mobile AV device
  • Digital still camera
  • Digital video camera
  • Electronic power meter
  • DVD recorder
  • TV, VCR
  • Mobile phone, PHS

Parts List

  • U(Ux), S and G at the end of the product name of ABLIC Inc. were used to indicate different material specifications as “environmental code”,
    however, these have now been unified into “lead-free and halogen-free” and are identical in terms of environmental quality.
  • Note: Lead-free plating other than 100% Sn is applied to some limited old products, therefore, please contact our sales representatives for details.
  • These descriptions may be different from the actual product name and parameter.
    Please confirm the product name and specifications with the data sheet again.
  • The information herein is subject to change without notice.