Where should I set GND?

I

iamkim

Newbie level 4
Joined
Mar 20, 2024
Messages
6
Helped
0
Reputation
0
Reaction score
0
Trophy points
1
Activity points
55
I am currently producing an active cell balancing model using the Resonant Switched Capacitor method. However, I am writing this because I have a question. I first grounded GND to the - part of the battery series, but if the odd MOSFET is closed during balancing, the source part of the MOSFET does not seem to be connected to GND. Should I connect GND to another part?
I am upload 2CEll and 3CEll Circuit. Thankyou for your interest. Have a good day!!



 

Sort by date Sort by votes
Hi,

The schematics show no GND at all... nor can I see where you intend GND to be.

Indeed the schematic is so incomplete .. thus it´s hard to give a good answer.
Controlling the MOSFETs you need some MOSFET drivers. How do they work, what input levels, what are they referenced to?

Basically MOSFETS are controlled by V_GS. The voltage between gate and source.
Thus: for each MOSFET you need the GATE voltage referenced to it´s SOURCE voltage. .. no matter which node you define as GND.

Klaus
 

Upvote 0 Downvote
Hi, Thankyou for your apply. I use TC4420 as Gate driver. and I just wonder Where should I put GND.
 

Upvote 0 Downvote
Hi,

as already said: The GATE must be driven with respect to SOURCE.

In case of TC4420: It´s OUTPUT is referenced to it´s GND. Thus:
TC4420_OUTPUT --> MOSFET_GATE
TC4420_GND --> MOSFET_SOURCE

wich makes the supply for each individual TC4420 rather difficult. And for sure the PWM_signal translation, too...

There is a good reason why there are dedicated HIGH_SIDE_MOSFET_DRIVERs

Klaus

PS:
Did you read some cell balancing application notes .. to see how they do it?
No need to re-invent the wheel. No need to make the same mistakes others already made.
--- Updated ---

At the Microchip (TC4420) internet site you find a lot of informations / Applicatin Notes on how to drive MOSFETs.
Other manufacturer provide more informations.
 
Last edited:

Upvote 0 Downvote
You must log in or register to reply here.

Similar threads

Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…