CBC910 datasheet(2/14 Pages) CYMBET

2 / 14 page

CBC910

DS-72-11 Rev 5

Page 2 of 14

Preliminary

Functional Block Diagram

Figure 2: CBC910 Internal Block Diagram

The CBC910 internal schematic is shown in Figure 2. The input voltage from the power supply (VDD) is applied

to the charge pump, the control logic, and is compared to the user-set threshold as determined by the voltage

on VMODE. VMODE is an analog input ranging from 0V to VDD. The ENABLE pin is a digital input that turns off the

charge pump when low. VOUT is either supplied from VDD or the integrated battery. RESET is a digital output that,

when low, indicates VOUT is being sourced by a backup battery.

CFLY is the flying capacitor in the voltage doubler circuit. The value of CFLY can be changed if the output

impedance of the CBC910 needs to be modified. The output impedance is dictated by 1/fC, where f is the

frequency of oscillation (typically 100kHz) and C is the capacitor value (typically 0.1µF). GND is system ground.

VCHG

GND

Electrical Properties

Battery Backup Output voltage:

3.3 V

Physical Properties

Package size:

3 mm x 3 mm x 0.9 mm

Die size:

0.96 mm x 1.36 mm (to center of scribe on wafer)

Operating temperature: -40°C to +85°C

Storage temperature:

-40°C to +125°C

CBC910 Datasheet(PDF) 2 Page - Cymbet Corporation