In need of suitable replacement of a custom motor driver

Hello all,

I’m not new to electronics but I wish I knew more than I do at times. I haven’t had much luck in forums like this, but here it goes anyway. To get down to it, I had a failure of a pump driver that drives a 12V AC motor pump, like you would see in a desktop “Zen” fountain or something like that. The only problem is there is no AC current in the automated self-contained hydro-garden; it is only fed by a 24V DC 1500mA power supply. I did a lot of mucking around to figure out how they accomplished this and with such little circuitry (see attached schematic). Lots more to learn, but what I gathered, I figure it’s probably a custom H-bridge IC that does the dead-time manipulation of the input square waves to prevent shoot-through (but not well enough!), and some internal filtering to create a sine wave output to drive the pump motor.

So, I’m not looking for a drop-in replacement, but if one exists, I’m all ears!

I was going through all the Half-Full H-Bridge motor drivers, and I need someone to help me filter through what matches best my needs. I see some that have dead-time insertion built in but are super complicated and some are super simple 8-pin soic (similar to mine but the pinout is different), but probably most don’t have dead-time built in. I guess I can learn and build a circuit to manipulate the duty cycle of the input square waves before the h-bridge driver (ugh!). Any help is appreciated and please let me know if more info is needed, as I’m sure there is and hopefully, I can fill in the gaps. I have an ancient O-Scope (Tek 465), but I’m not afraid to use it!


That is a tricky one. I have reached out to our other techs and engineers for help with your question. I will let you know what I am able to find out.

If you make your design using L298 or L293D, will there be any problem?

Hi Thanks for your reply!

After looking at them, no, because both operate at 5V and all I have available is 3.3V and 12V. the old one seemed to use Vsource (12V) for both logic (if there was any, it would have probably stepped it down internally) and drive voltage. I’m hoping there’s something that operates at CMOS level? 3.3V?

Thanks! My whole goal is not to drop-in replace the ic in question, but to construct a similar design that would use the given inputs of the MCU and restore MCU control of the water pump.

If you’re looking for 3.3V H-bridge, you can take a look at TA6586.

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Hi bidrohini, Yes its actually a dead-ringer on the outside, im going to see how available it is. I could definately work with this. Thank you very much!

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The stock looks limited here:

By the way, I think L298+ logic level converter (3.3V to 5V) can be an alternative.

I didn’t realize something like that exists, but ok, that definitely opens up the field a bit, I’d have to test it out. I have an Arduino Uno already to toy with, but maybe I’ll get a Nano (3.3v logic level) to simulate the hydo-garden’s MCU. is the lL298 available as an evaluation board? I actually already ordered the L293 shield for the uno just to test some stuff I’ve been knocking around in my head for proof-of-concept of using a device that it wasn’t exactly designed for what I’m about to do with it. Hopefully I don’t blow it up on the first try. Thanks!