BQ32002 Datasheet, PDF (19/29 Pages) Texas Instruments – BQ32002 Real-Time Clock (RTC)

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8 Application and Implementation
BQ32002
SLUSA96B – AUGUST 2010 – REVISED APRIL 2016
NOTE
Information in the following applications sections is not part of the TI component
specification, and TI does not warrant its accuracy or completeness. TI’s customers are
responsible for determining suitability of components for their purposes. Customers should
validate and test their design implementation to confirm system functionality.
8.1 Application Information
The typical application for the BQ32002 is to provide precise time and date to a system. The backup power
supply provides additional reliability by automatically switching over from the main supply when it drops under the
voltage threshold.
8.2 Typical Application
The following design is a common application of the BQ32002.
bq32002
V _CC
OSCI
V _CC
32.768 kHz
OSCO
1 µF
4.7 kΩ 4.7 kΩ 4.7 kΩ
V _BACK
GND
IRQ
SCL
SDA
Copyright © 2016, Texas Instruments Incorporated
Figure 8. Typical Application Schematic
8.2.1 Design Requirements
Table 17 lists the parameters for this design example.
DESIGN PARAMETER
Supply Voltage
Backup Supply
Crystal Oscillator
Table 17. Design Parameters
REFERENCE
V_CC
V_BACK
XT
EXAMPLE VALUE
3.3 V
BR1225
32.768 kHz
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