Precision synchronous demodulator

Started by Spehro Pefhany in sci.electronics.design7 years ago 49 replies

What's a good approach for use at 1MHz, give or take 2:1? Things like the AD630 are slow, and my usualy go-to approach (Gilbert Cell balanced...

What's a good approach for use at 1MHz, give or take 2:1? Things like the AD630 are slow, and my usualy go-to approach (Gilbert Cell balanced demodulator with LO > > Vt) has input referred drift and offset typically in the ~1uV/K and a couple mV. I'd like both to be better by at least an order of magnitude, and preferably with some gain like the Gilbert cell things, which have 15-20dB of ga


HD Video Specs.?

Started by Jim Thompson in sci.electronics.design6 years ago 23 replies

Can someone direct me to some specifications for HD video? I've had an inquiry regarding an HD video demodulator (FM), I'm zeroing out with...

Can someone direct me to some specifications for HD video? I've had an inquiry regarding an HD video demodulator (FM), I'm zeroing out with Google (probably not the right search buzz words). Thanks! ...Jim Thompson -- | James E.Thompson | mens | | Analog Innovations | et...


wideband FM demodulator

Started by John Larkin in sci.electronics.design2 years ago 56 replies

We're thinking of sending a wideband (say, dc to 50 MHz) signal using FM. The carrier could be in the 500 MHz to 1 GHz range maybe. I can...

We're thinking of sending a wideband (say, dc to 50 MHz) signal using FM. The carrier could be in the 500 MHz to 1 GHz range maybe. I can get the VCO. What's a good way to do the FM discriminator these days? I could homebrew a quadrature detector, with some resonator and an XOR gate or a mixer, but there must be some easier way to do it. Not being an RF type, I'd appreciate suggestio...


Detector question on lock-in circuits

Started by Anonymous in sci.electronics.design7 years ago 1 reply

I see demodulator circuits that to me look like a full wave rectifier, they take an AC signal and flip its negative part above the line. This is...

I see demodulator circuits that to me look like a full wave rectifier, they take an AC signal and flip its negative part above the line. This is the last stage of a lock-in before the integration-cleanup phase. In situations where you control the light source, I have thought of using square wave pulses, with measurements taken during 'on' and 'off' periods. It makes sense to me to subtract...


Diode Array

Started by Anonymous in sci.electronics.design3 years ago 10 replies

I'm looking for a replacement for the CA3039 diode array, which has been successfully used in a precision demodulator circuit operating up to 1...

I'm looking for a replacement for the CA3039 diode array, which has been successfully used in a precision demodulator circuit operating up to 1 MHz. The part has been obsoleted by Intersil. The important characteristics are low leakage current (less than 0.1 nA at 25C with 1 V reverse bias) and close matching of forward voltage drops. Also, the forward voltage drop with 1 nA or le