BQ24610: Datasheet Fig 20 -- Q2

steve wenner

Part Number: BQ24610

Good afternoon..

Can you please tell me the purpose of Q2 in Figure 20 of the datasheet for BQ24610? Seems to me that it is NOT necessary from a charging standpoint as Q3 body diode will block the AC/DC converter from feeding battery directly and if AC/DC converter is removed, the battery will not have to have a body diode drop from Q2 to power VCC. The only thing I can think is Q2 is allowing the load (SYSTEM) to have a controlled turn on through R18/C14???

Thank you

Steve

over 5 years ago

0 Kedar Manishankar over 5 years ago

TI__Mastermind 24075 points

Hi Steve,

Yes this helps provide a controlled dI/dT when connecting adapter to the system by controlling the FET turn on time. Q1 helps provide reverse battery discharge protection when off, while also minimizing power dissipation when on, as power loss over RDSon will be less than the forward voltage drop of a schott diode.

0 steve wenner over 5 years ago in reply to Kedar Manishankar

Expert 2355 points

Thanks Kedar for the confirmation....

That was what I was thinking

Steve

0 Kedar Manishankar over 5 years ago in reply to steve wenner

TI__Mastermind 24075 points

No Problem!

Power management

Power management forum

BQ24610: Datasheet Fig 20 -- Q2