DocID024974 Rev 3

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PM6613N

Operating description

of CHRG_OPT register. When ACOK is high, the ACFET selector has to be switched on, in

order to supply the B2B pin. This pin is used to provide the offset for the charge pump that

supplies the ACFET/RBFET selectors. Once B2B reaches the 2.5 V threshold, the BATFET

selector is switched off and the battery is disconnected from the system: in this case the

current flows to the system through the body diode of the selector. When the B2B pin

crosses the battery voltage (sensed by SRN pin) by 255 mV, the RBFET is switched ON.

From now on the system is supplied by the adapter. The described sequence is summarized

in the below table:

4.12

Adapter removal

When the adapter is unplugged, a disconnection sequence occurs, bringing the charger into

a sleep mode. When the ACDIV pin goes below 1.95 V, the ACOK pin goes immediately

low: there's no deglitch time in this case. Any charging process is interrupted and the B2B

pin is internally discharged. The B2B pin is used to sense the system voltage through the

ACFET/RBFET selectors. When the B2B pin goes below the value of the battery plus 225

mV, the ACFET/RBFET selectors are opened if SOVR bit of CHRG_OPT is set, and the

BATFET selector is closed if the BSE bit of CHRG_OPT is set, allowing the battery to supply

the system. As the system voltage is much closer to the battery voltage, any inrush current

caused by system capacitors is avoided. When the ACDIV voltage goes below 0.6 V the

PM6613N is in sleep mode. The sequence is summarized in Table 15

Table 14. Adapter insertion sequence

Condition

Action

Adapter insertion

ACDIV voltage rises

ACDIV > 0.65 V

PM6613N goes out of sleep mode

B2B pin forces a low voltage

ACDIV > 2 V

ACOK pin goes high after 250 ms

B2B pin stops forcing voltage

ACFET is turned on

B2B voltage rises

B2B > 2.5 V

BATFET is off

B2B > SRN+225 mV

ACFET/RBFET is on

Table 15. Adapter removal sequence

Condition

Action

Adapter unplugged

ACDIV voltage decreases

ACDIV < 1.95 V

ACOK goes low

B2B pin forces a low voltage

Internal circuitry disables any charging process

B2B < SRN+ 225 mV

ACFET/RBFET selectors opened

BATFET selector closed

ACDIV < 0.6 V

The PM6613N is in sleep mode