how to increase output current

[siaug18]

I have designed a microstepping circuit using the imt-901 ic, now i need to increase the output current from 3A/phase upto 7A/phase. i was thinking if using some darlington pairs but i dunno.....

as any one done anything like this ?

need some advise.....


cheers

[jeffs555]

There would be many problems doing this for a bipolar drive. The main problem is that there is only one output for each half bridge. You cannot drive both high and low side transistors directly from this one output without significant crossover problems which would probably destroy the added transistors. There are bridge driver IC's that have crossover delay built in, but they tend to be slightly expensive, and usually have fairly low voltage ratings.

[siaug18]

ok cheer...

any idea how i can increase the output current from 2A/phase to 7a/phase ?

[siaug18]

cheers...... (thats what i ment to say)

[NC Cams]

Anymore, darlingtons are clunky and expensive. Fets are the way to go.

IRLZ40/44's or IRFZ40/44's will easily carry 7 amps.

IR just released a high side driver that facilitates H bridge switching and has "shoot thru" protection built in.

There is a thread that recently ran about driving an "H bridge" on this M/B. You might find it to be helpful in doing what you're trying to do.

[siaug18]

the imt-901 microstepper ic has the h-bridge in-built.....

not much i can do with it !!!!!! (