Newbie- Quick Questions about A3977

[Jesse B]

I just have a few quick questions about Allegro's A3977 chip

1) Is it true that you should not use a socket with these, due to their method of using the ground pads as heat sinks? If so, would it be beneficial to have a large copper pad underneath the chip on the board, and use some thermal paste, or would it just be a waste of time?

2) I know it says the limit of this chip is 2.5A, but would it be able to handle 2.8A with heat sinks and lots of airflow?

Thanks,


- Jesse

[ger21]

PMDX used to get 3 amps out of them.
http://www.pmdx.com/PMDX-150

[Jesse B]

Awesome, thanks

[Jesse B]

Also, I've been looking at two different designs for a A3977 board:

1) THS Engineering: http://www.thsengineering.com/projec...3977proto.html
2) PMinMO A3977: http://pminmo.com/ss3977/ss3977.htm

I was wondering if anybody had any schematic/board files for either? I'm not very good at making schematics yet, and I don't have all the libraries I'd like. Thanks

[Jesse B]

Nobody has anything? Guess I'll just have to suck it up and make it myself then