Power Switch

[SHa]

Hello,

Please, can someone explain me why this power switch has been designed like that (refer to the attached picture)?
And especially what is the purpose of R7/C14?

Thanks.

   

[Charming]

It's a soft-start circuit. The soft-start circuit is used for reducing the peaks while powering on (controlled by PANEL_ON pin) of the EPD.

• When PANEL_ON = Low, Q5 off, Q4 on, Q3 off. The C14 will be full charged.
  
• When PANEL_ON = High, Q5 on, Q4 off, R7 and C14 will be discharged slowly leads to Q3 turns to ON, then you will get VCC_T to input VCC3V to driver of EPD.
  

[SHa]

Ok, understood.
Thank you very much.