Electronics > Metrology
Building your own voltage reference - the JVR
Kleinstein:
One still needs the OP-amp to do some amplification of the source voltage. So one would either use the amplified votlage from OP-amp or the source votlage without gain, but a bit higher impedance ( the resistor and some 150 ohms (1/gfs) from the FET.
So far I found the compensation of the 2nd order effect tricky and prone to add drift. So my preferred way is a regulated temperature.
imo:
--- Quote from: dietert1 on October 07, 2022, 11:34:20 am ---Yes, it's great to use the second JFET for TC adjustment (on-chip sensor). What would be the reference voltage?
--- End quote ---
I've just tried with my dual jfet DGN349 (bootstrapped by an OP07, standard wiring) and I get around 0.75V at 0.4mA Ids.. (max 0.86V with 5k resistor).
dietert1:
That low reference voltage is a disadvantage for many applications. In my case i want to add a 10 V gain stage, to make it into a 10 V lab reference.
Regards, Dieter
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