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GG25L

Functional description

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6.5

Improving accuracy of the initial OCV measurement with the

advanced functions of BATD/CD and RSTIO pins

The advanced functions of the BATD/CD and RSTIO pins provide a way to ensure that the

OCV measurement at power-up is not affected by the application startup or by the charger

operation. This occurs as follows:



(assuming that the BATD/CD signal is connected to disable input of the charger circuit).



The RSTIO pin senses the system reset state and if the system reset is active (that is

RSTIO is low), the RSTIO is kept low until the end of the OCV measurement.

Figure 10

describes the BATD/CD and RSTIO operation at power-up. Please refer to the

block diagram of Figure 11 for the RSTI, RSTO, BATD_comp_out, and BATD_drive_high

signals.

At the end of the OCV measurement, the BATD/CD and RSTIO pin are released (high

impedance), the application can start and the charger is enabled.

Figure 10. BATD and RSTIO timing diagram at power-up

6.5.1

BATD and RSTIO pins

The GG25L provides platform synchronization signals to provide reliable SOC information in

different cases.

The BATD/CD pin senses the presence of the battery independently of the battery voltage

and it controls the battery charger to inhibit the charge during the initial OCV measurement.

The RSTIO pin can be used to delay the platform startup during the first OCV measurement

at battery insertion.

VCC

UVLO

BATD_comp_out

RSTI

POR

Voltage

measurement

1.61V

delay

RST0

Voltage

register

SOC register

BATD_drive_high

OCV

meas.

Application can start,

charge is enabled

SOC

calc.