Tuesday, October 30, 2007

DAC I/V stage

It seems that transformer I/V is not so simple. Well it is, but I was not sure it will work and to test it I would need to but transformers that are very expensive. Too expensive to play with. OK, so I started to study solid state I/Vs. Op-amps are no go. I/V should have ideally 0 ohm impedance to DAC and be very low noise. After a few days of studying transistor topologies, current mirrors/sources, I came up with idea (not new): common base + current mirror + resistor (+ buffer). AD844 (used as common base; trans. current. amplifier) is very good and easy start, making a discrete one (see Pedja Rogic circuit). I did simulations and I will try those... :)


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