Precision synchronous demodulator

Started by Spehro Pefhany in sci.electronics.design4 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.design3 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...


Detector question on lock-in circuits

Started by Anonymous in sci.electronics.design4 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.design1 month 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


Re: IR Receiver/Demodulator

Started by Jim Thompson in sci.electronics.design8 years ago 2 replies

On Fri, 19 Mar 2010 08:50:01 -0700, Joerg wrote: > markp wrote: [snip] > > > > Other possibilites for the receiver might be to use a...

On Fri, 19 Mar 2010 08:50:01 -0700, Joerg wrote: > markp wrote: [snip] > > > > Other possibilites for the receiver might be to use a tube, cone or even a > > parabolic reflector made from IR reflective material. If you use the > > reflector you'd place the receiver pointing inwards at the focal point. This > > effectively produces gain as it captures power from a


IR Receiver/Demodulator

Started by eeboy in sci.electronics.design8 years ago 81 replies

I need to design an IR receiver which will demodulate IR input at a given carrier frequency (~32kHz) over distances of 60-80 feet. I am...

I need to design an IR receiver which will demodulate IR input at a given carrier frequency (~32kHz) over distances of 60-80 feet. I am not transmitting data, simply pulses of varying length (20ms-80ms). These pulses occur at the rate of approximately 1Hz. It is important that the pulse length is preserved from transmitter to receiver. In other words, if I send a 20ms pulse I expect it to be withi...