The EnerChip RTC CBC34813-M5C combines a Real-Time Clock (RTC) and calendar optimized for low power applications with an integrated rechargeable solid state backup battery and all power management functions.

The EnerChip RTC ensures a seamless transition from main power to backup power in the event of power loss. The integrated power management circuit ensures thousands of charge-discharge cycles from the integrated EnerChip and manages battery charging, discharge cutoff, power switchover, and temperature compensation to maximize the service life of the device. The CBC34813 provides greater than 5 days of backup time in the event main power is interrupted. The integrated EnerChip recharges quickly, has extremely low self-discharge, is non-flammable, and RoHScompliant. The EnerChip is charged automatically anytime VDD is above 2.5V.

Data is transferred serially via an SPI-bus. Alarm and timer functions provide the option to generate a wake-up signal on an interrupt pin.

EnerChip RTC lasts the life of the system so you never have to change a battery. EnerChip RTC devices provide powerful single chip drop-in capabilities in the world’s smallest footprint.
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  • Ultra low power Real Time Clock with Integrated rechargeable EnerChip™ solid state battery, power-fail detect and automatic switchover, providing greater than 5 days (typical) of RTC backup
  • 5mm x 5mm x 1.4mm QFN package is the smallest commercially available RTC having integrated backup power
  • Temperature-compensated charge control
  • Integrated EnerChip™ recharged at VDD > 2.5V
  • SMT assembly – lead-free reflow solder tolerant
  • Counters for hundredths, seconds, minutes, hours, date, month, year, century, and weekday based on a 32.768 kHz oscillator
  • Automatic leap year calculation
  • Alarm capability on all counters
  • 2 general purpose outputs
  • 64 bytes of RAM
  • Advanced crystal calibration to ± 2 ppm
  • Advanced RC calibration to ± 16 ppm
  • Automatic calibration of RC oscillator to crystal oscillator
  • SPI-bus (up to 400kHz)
  • Eco-friendly, RoHS compliant – tested

Physical Properties

Package size: 5 mm x 5 mm
Operating temperature: -10°C to +70°C
Storage temperature: -40°C to +125°C

Electrical Properties

Output voltage: 2.5V
Capacity (typical): 5µAh
Recharge time to 80%: 15 minutes
Charge/Discharge cycles: >5000 to 10% discharge


  • Power bridging to provide uninterruptible RTC function during exchange of main batteries.
  • Consumer appliances that have real-time clocks; provides switchover power from main supply to backup battery.
  • Ultra Low Power Timersusing only 35nA can be implemented with the CBC34813
  • Wireless sensors and RFID tags and other powered, low duty cycle applications.
  • Business and industrial systems such as: network routers, point-of-sale terminals, single-board computers, test equipment, multi-function printers, industrial controllers, and utility meters
    • Power bridging to provide uninterruptible RTC function during exchange of main batteries.Time keeping applications
    • Battery powered devices
    • Metering
    • High duration timers
    • Daily alarms
    • Low standby power applications

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