still for example I see a 60V dcdc advertised at AlieX LT3800EFE with date codes 2013 etc. the chip is 9usd at digikey, and 3usd as a complete dcdc converter including board, caps, inductor. more than 100k chips available at AlieX. i'm puzzled
The 1000+ quantity direct from analogue devices is more than 3usd. Maybe back in 2013 they cost $2 each and they've got surplus stock of these converter boards. Either that or the chip is a fake.
A quick test to see if it is a LM358. the LM358 has a PNP input vs the 5532 is NPN. so the bias current is such that the LM output is always a bit lower than the input as the output has to sink current into the input.
Most of the stuff they sell is factory defects, used ones, fake ones or legit ones. Its hard to find a legitimate seller. In my case after asking the seller, the LME chip was salvaged from a preamp. Electronic components are super cheap in china with cheap labor they make profit on a 3$ board with everything installed. The available stock is fake most of the times just ignore it.
@5th element Dont forget that in china the chips are being sold for pennies.
Point is that you'll never know if they original or not and if they didn't deteriorate from ESD damage. If you see the videos how parts are being cooked off the boards in pans...
There is a high chance of channel differences etc. This can already happen with reusing ICs you yourself desoldered.
There is a high chance of channel differences etc. This can already happen with reusing ICs you yourself desoldered.
i'm just kinda curious, a lot of these OPA and muses opamps' operating voltage range is around +-16V but the amp internal DC is 25V ? Wouldn't this fry the opamp ? On the other hand, NE5532 seem to be rated at +-22V. Thanks.
It runs on 25V single rail and not on +- and that is equal to +-12.5V so almost every opamp can be used.