STBC21 datasheet(49/54 Pages) STMICROELECTRONICS

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STBC21

Charger, battery and alarm status registers

Doc ID 023256 Rev 1

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H.1

Layout guidelines

The layout of the application board for the STBC21 is very critical due to the high precision

required on charging parameters which can be met only by minimizing the voltage drops

across the connecting tracks and the noise in the ground plane.

For these reasons the following guidelines are strongly suggested:

Input and output decoupling capacitor should be placed as close as possible to the

STBC21 with short trace runs to both IN, OUT.

All low current GND connections should be kept separate from the high current charge

or discharge paths from the battery.

Use a single-point ground technique incorporating both the small signal ground path

and the power ground path.

The high current charge paths into the IN pin and from the OUT pin must be sized

appropriately in order to avoid voltage drops in these traces.

VBAT_SNS must be connected to VBAT as near as possible to the battery pin.

The layout of the board is reported below.

Figure 17.

Layout board (top through view)

Table 46.

Battery temperature range

000

No battery

001

Battery temperature > 60 ºC

010

Battery temperature > 50 ºC

011

Battery temperature > 45 ºC

100

Battery temperature > 10 ºC

101

Battery temperature > 0 ºC

110

Battery temperature < 0 ºC

111

Battery temperature < 0 ºC

STBC21 데이터시트(PDF) 49 Page - STMicroelectronics