Thanks, SY. I could build a current source like this one: http://sound.westhost.com/ab-f5-2.gif However, PCB space is limited, so it'd have to be kludged in there. I've found that the 1N5302 should do the job and can find them in the UK: http://www.centralsemi.com/PDFs/products/1N5283-5314.pdf
What's the advantage of making one from a Jfet + R?
J
What's the advantage of making one from a Jfet + R?
J
Well, one advantage is that you can buy them easily and they're cheaper.
All a CCS diode is is a FET with the gate and source shorted together and running at the FET's Idss. If you use a resistor to bias the FET to a lower current, the drain impedance rises (what you want for a CCS). So, lower cost, only two parts (a FET and a resistor), higher performance... why bother with a CC diode?
All a CCS diode is is a FET with the gate and source shorted together and running at the FET's Idss. If you use a resistor to bias the FET to a lower current, the drain impedance rises (what you want for a CCS). So, lower cost, only two parts (a FET and a resistor), higher performance... why bother with a CC diode?
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