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wagiminator / ATmega-Soldering-Station

T12 Quick Heating Soldering Station
https://oshwlab.com/wagiminator/z-solderingstation-smd-v2
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What is the role of the op amp on the right side of lmv358？ #17

Closed Eddddddddy closed 3 years ago

Eddddddddy commented 3 years ago

I am trying to understand the right op amp. I don’t know why you design it like this. I'm really not good at this. IMG_0143

wagiminator commented 3 years ago

Hi, the second OpAmp of the LMV358 is not used. An unused OpAmp should not float, as this can interfere with the OpAmps in use or, in the worst case, lead to its destruction. The two resistors stabilize the second OpAmp by forming a unity gain amplifier (or buffer) with VCC/2 as a fixed positive input value.

Eddddddddy commented 3 years ago

Thanks for this answer. I got it!

Eddddddddy commented 3 years ago

by the way. Can I use OPA333 replace LMV358? I rebuild the PCB project. OPA333 is much smaller than LMV358.

wagiminator commented 3 years ago

Yes, of course, that should work fine.

Eddddddddy commented 3 years ago

thanks！！