Current draw of hot-running op-amps
Quote:
Originally Posted by Pars  Measure the current draw... if it is within datasheet ranges, you're probably ok
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Oh, sorry. Forgot to post this (it was in the Ref links above, however.):
Some current and temperature measurements taken for three experimental opamps in the circuit
shown here:
AD843 (two DIL-8 Brown Dogged pairs per stereo channel): 23.5 mA / 112F (44.4C). Datasheet PS Quiscent current (Iq): 12 - 13 mA
AD797 (two DIL-8 Brown Dogged pairs per stereo channel): 15.8 mA / 97F (36C). Datasheet PS Quiscent current (Iq): 8.2-10.5 mA
AD825 (two SOIC-8 Brown Dogged pairs per stereo channel): 12 mA / "cool" (room temp.). Datasheet PS Quiscent current (Iq): 6.5 - 7.2 mA
I also spoke with two separate Analog Devices "opamp engineers" who both concurred that the AD843 is probably the better choice here (despite it running "hotter") because it is unity gain and FET.
Both also concurred that the AD797, a bipolar design, is trickier to implement in this app. because it is not unity gain, susceptible to current noise and, hence, may oscillate.
