Multiplier Chip ad633

[Tony]

Does anyone know if the 633 chip could be made functional without using a bipolar power supply?

Thank you,
Tony

[Paul Perry (Frostwave)]

I think the voltage ratings for 'good' operation are +-8 to +-18.
I believe it will operate at a bit less, but the whole point of using an AD633 is to get the superior performance.
If you want a low voltage ring modulator, you might as well use a
CA3080 multiplier circuit.
Incidentally, ANY bipolar circuit can be converted to single supply, by fixing up the bias (that is, adding offsets to the various parts).
But if you are trying to do this for a 9v battery, you will be out of luck with an AD633, I suspect.
To get stable performance and negligible carrier bleedthru, I use +- 15v regulated rails, and very careful layout. And multiturn trimpots!
I suspect that an OTA based multiplier is going to want a stabilised supply, incidentally. (I might be wrong... let me know if I am!)

[Tony]

Hi Paul,

Thanks for the info. This is all relatively new to me. I've made some simple effects but now trying to move forward. The whole bipolar power supply seems like a lot of work. I'm trying to keep things on the low voltage side particularly because I have no experience with using high voltages. (I don't mind using wallwarts, but once I start making things that take 120 volts and convert it to 15V, or 12V I get worried. I feel like I should also include a smoke detector somewhere inside the box.)

Can you refer me to any info on converting bipolar to single supply?

I'm also looking at the 8038, another bipolar design. But it does state in the datasheet you could run it with a single voltage supply.

Thanks again for the info, I appreciate it.

Tony

[Paul Perry (Frostwave)]

I don't mind using wallwarts, but once I start making things that take 120 volts and convert it to 15V, or 12V I get worried.

Well in my commercial gear, I have an AC output wallwart (somewhere from 14 to 16v Ac output).
Tie one of the AC outs to ground, the other goes to a couple of half wave rectifiers, then the raw DC (which peaks at 20 to 25V, don't underestimate the filter caps ratings) goes to + and - 15v regulators.
So I'm nowhere near the mains, at least not runing 230v into anything.

[ricothetroll]

Hi Paul,

I'm currently doing tests with the AD633. I found out that getting rid of the bleed of a perfectly sinusoidal carrier is pretty easy following your advices (intelligent layout and decoupling) but I still can't get rid of the harmonics of a triangle carrier or, even worse, of a square wave signal. Did you try other waveforms for the carrier ? How successful were you getting rid of the harmonics ?

I'm running on +/- 12V, generated by two TC962, from a 9V input.

Best regards.

Eric