Q : Is it acceptable EN connect to IN directly? (It means MAX77827 is always on after battery is connected.)
A : The absolute max rating for EN pin is Vbias+0.3V and the Vbias is will be higher voltage…
Q : What is MAX77827 Vbias voltage?
A : The Vbias is an internal driver supply voltage and it is connected to higher voltage of VIN and Vout. So if VIN is higher than Vout, then VIN will be connected…