Дык в даташите написано же что на A есть SECFB (Pin 20), а на B он не используется
Цитата:
SECFB (Pin 20) (RT8206A)
The SECFB is used to monitor the optional external 14V
charge pump. Connect a resistive voltage-divider from the
14V charge pump output to GND to detect the output. If
SECFB drops below the threshold voltage, LGATE1 will
be turned on for 300ns. This will refresh the external charge
pump driven by LGATE1 without over-discharging the
output voltage.
Т.е. для запуска A неоюходим charge pump
