STBC21 datasheet(15/54 Pages) STMICROELECTRONICS

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STBC21

Detailed description

Doc ID 023256 Rev 1

15/54

5.2

Battery connection detection

The STBC21 includes a battery detection algorithm to avoid a wrong behavior of the charger

due to incorrect pin connection. This control is performed both at the beginning and at the

end of charge.

At the beginning of charge, the charger briefly (TDETECT) sources a small current (IDETECT)

to the battery: if the voltage remains below VRECH, the battery is definitely connected.

Otherwise, if the voltage reaches VRECH, a further control is added to be sure the battery is

not connected. The charger briefly sinks (TSINK) a small current (ISINK) from the battery. If

voltage falls below VPRE_CH, the battery is certainly absent.

Similarly, when the termination current is reached, the charger briefly (TSINK) sinks a small

current (ISINK) from the battery. After this period, if the battery voltage is above VPRE_CH, the

battery is present. Otherwise the battery is absent. The flowcharts in

Figure 5 better explain

this algorithm.

STBC21 数据表(PDF) 15 Page - STMicroelectronics