| Higo |
Hi guys:
I´m designing my first GC based on LM3886TF (Po=50W, VCC=+/-35V, Icc=3.5A, Av=20). I read in the specifications manual that the lm3886 has excellent power supply rejection and does not require a regulated power supply. But I have a pair of LM317T/337T and 2N3055 and 2N2955 and I was thinking to build a regulated PSU . Will It improve the performance of the GC if a use a regulated PS? Is it worth the effort?
Any advice will be appreciated.
Thanks,
Marcelo |
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| jackinnj |
I wouldn't bother with regulation of the power supply, just select the correct transformer for the application -- you don't need to go overboard on filter caps either. When you regulate you are just adding more "huffing and puffing" via the feedback circuit in the LM317 and burning watts via the '3055/'2955's.
build the power supply section first and see what it actually capable of delivering work, then backwards to determine the feedback resistor (gain) for the specific load impedance -- National Semi has the procedure on the PDF for the device (at least they have it for the LM3875).
the best advice that I have seen is to keep the lead length short -- I have found that the devices I've built with surface mount resistors work wonderfully (I've built about 8 so far with a variety of chips -- 1876, 3875, 3886.)
Jack |
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