well . I don't know if that's the correct forum to discuss that subject ,
I'm working on high power electronic load , but first . I decided I deeded 0-1A load , so I've build it ,
I used lm324 and just random 13007 ( I thought it was a Nmos , but it turned to be NPN transistor ... )
work's , the shunt is just 1 ohm probably 1W 1% resistor from cheap Chinese (damm ) multimeter that blew in my hand while measuring mains volts , stupid meter ! ,
anyway , the shunt is +- couple of milivolts out ( at 1A setting ) .
when I received my 5X units of the mcp6V27's , I decided I'll protect the VDD of the op amp via connecting it throe the 0-1A (also have another mode-> 0-100mA ) , I've set the current max to be approx 3mA , and it work's quiet fine ( I by mistake over loaded the VoutA of the op amp ) and the current jumped from 1.2mA to 3.3 or so ,
then 2 days later , I plugged the op amp opposite (
) and the load wasn't fast at all , the current rose to few hundred of mA's and then settled at 3.3mA , the op amp smoked and I was crying ( it had cost me a lot ! )
so I have 4 more units , I decided to do a faster 0-1A load ( just changing the shunt and the op amp to the mcp6V27 ) ,
I've changed the shunt to 50mohm one ( lower voltage operation ,+ lower power on shunt = more stable )
it turns out that 2uV op amp can be out by quiet a lot ! ,
0-100mV and it can be anyway from 9uV to 20uV , lower than 1.278 (or so ) mV and it remain in that voltage ,
is that's related to the fact that it's been powered by 1X( 4.5V) power supply ( can not reach negative rail ? )
and what about the +- 9-20uV ? I'll mention that above 100mV it goes to 2.5-3uV as quoted on datasheet (I think )
NOTE(1): by putting some cap between the VoutA and GND , I get +- 10uV at the range of 0-100mV
NOTE(2): the circuit is half on variboard and half on bread board , with like 10C'M long , approx 20AWG wiers
thank you in advance and sorry for the long post
NOTE : I'm not shure if the title is fine either , please tell me if it doesn't , thank you !