Chip Audio Amps as Motor Controllers?

[chipslinger]

Does anyone have experience using chip audio amplifiers as DC motor controllers?

I know there are some obvious issues such as poorly-specified offsets, but I was wondering if there were any other reasons I couldn't use these parts in this application. The most useful topology for me would be using a stereo amplifier chip as a linear full-bridge motor amplifier.

I've used the TI OPA548 like this before, but it is a general purpose high power op amp and a bit expensive for what I'm working on.

There seem to be some well-protected parts from National Semiconductor and NXP.

If anyone has any thoughts, warnings or other related experience, I would be very grateful. Thanks.

[pacificblue]

No personal experience, but I've seen people doing it with LM1875 and TDA2030. The LM1875's predecessor even states 'Motor speed controls' under Applications in the datasheet.

And you can always find dedicated power op amps for that task, e. g. the OPA544

[EBM_dude]

The TDA2030 is explicitly labelled as a 3A driver.

[chipslinger]

Thanks for the info. Sounds like this is at least a sane thing to try, so I"ll order a few parts to play with on the bench.

[EBM_dude]

The L165 datasheet contains some nice applications for that chip. If you compare it's properties to that of a TDA2030, you'll notice that they're "similar"....
BTW, I was wrong. The TDA2030 isn't labelled as a driver, the TDA2030A (!) is labelled as one.

[star882]

It's possible but overkill. Very simple PWM is all that's needed for a motor. Also note that even the largest audio amplifier is small by motor control standards.

Then again, in the movie "Who Killed the Electric Car?". one of the engineers described the motor controller as a "3 channel stereo amplifier to generate the right size sine waves for all driving conditions".

[Juergen Knoop]

using TDA2030 is simpler!
Regards

[Steerpike]

Something I'm currently working on using the L165 for a Technics DD motor.
Its a work in progress still.