> I'm thinking of the SSM2164 as well... it looks like it could go > in an opamp feedback loop. That's how we "linearize" it, actually. I've used two linearized 2164 VCAs (which means all four VCAs on the chip) to make a very nice four-quadrant multiplier. It's very straightforward. I'm not sure about division -- never given it much thought I'm afraid.