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Analogue Mulitiplier

Analogue Mulitiplier

Analogue Mulitiplier

can anyone help
I'm using an AD633JN analoge multiplier which is to expensive.
Can anyone suggest alternatives (Im using it as a sine wave phase detector)
many thanks

RE: Analogue Mulitiplier

it's very easy to make an analoge multiplier
you can use two logarithmic amplifier then an adder then an anti logarithmic amplifier to make a multiplier.
with just four OP-AMPs and two diods or two transistors and it's very low cost.
with this theory:
because ln(x)+ln(y)=ln(x*y) and then exp(ln(x*y))=x*y
and making logarithmic and antilogarithmic amplifiers and an adder is very easy.
if you don't know what is a logarithmic amplifier
and you can not make this simple circuit
please email me to this address

i'll be glad to help you.

RE: Analogue Mulitiplier

Check the Analog Devices site. I recall they recently introduced a specific phase detector chip. It may not operate low enough in frequency for you though.

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