DS-72-34 Datasheet, PDF (1/18 Pages) Cymbet Corporation – I2C Real-Time Clock/Calendar with Integrated Backup Power

Preliminary
CBC34803 EnerChip™ RTC
I²C Real-Time Clock/Calendar with Integrated Backup Power
Features
• 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 battery 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
• I²C-bus (up to 400kHz)
• Eco-friendly, RoHS compliant - tested
Applications
• 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 Timers using only 35nA can be
implemented with the CBC34803
• 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.
• Time keeping application
• Battery powered devices
• Metering
• High duration timers
• Daily alarms
• Low standby power applications
5mm x 5mm x 1.4mm 16-pin QFN Package
General Description
The EnerChip RTC CBC34803-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
CBC34803 provides greater than 5 days of backup
time in the event main power is interrupted. Longer
backup time can be achieved by adding an external
EnerChip to the VCHG pin. The integrated EnerChip
recharges quickly, has extremely low self-discharge, is
non-flammable, and RoHS-compliant. The EnerChip is
charged automatically anytime VDD is above 2.5V.
Data is transferred serially via an I²C-bus. Alarm and
timer functions provide the option to generate a
wake-up signal on an interrupt pin.
XI
XO
Figure 1: CBC34803 Pin-out Diagram
©2014-2015 Cymbet Corporation • Tel: [phone] • www.cymbet.com
DS-72-34 V.20
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