Substituting a HA-5221 opamp

interesting. after looking at the details i would say if you could get your hands on a old LM747 chip which is a higer voltage and sliglty more current than the generic 741 chip i think you can get by.. actually i think a 741, TLO80 etc would handle 40 Ma.

Philip Pembert> Hi,

LM747 is a dual 741. That and according to National Semiconductor it can only do 25mA per channel - same goes for the 741. That and the 741 is about as noisy an opamp as you can get :-/

TL081 -> 12mA per channel according to Natsemi's website. The LM7171 looks suitable, and at least it's cheaper than Analog Devices's offering. I'll get a 7171 from Farnell when the Maxim stuff arrives - then I'll see just how well the curve tracer works :)

Thanks.

hmm, thats strange. my old Itel ref and i mean old does state that a 747 can handle 50 Ma. but after looking at intel onlines docs, they are not the same as my old printed book i must take note of this because we recently have been replacing 747 chips more so that we should have, the original chips lasted for years, then when they started go we now have problems running the boards with out blowing over heating the chips now. we have been installing cabinet fans to over come the problem, we never had to do this for years actually i do remember seeing some special additional prefix numbers on the package that are not on the replacement chips we now use from intel.

Philip Pembert> [Posted and mailed]