Going back to electronic after a 20 years break

Now that' i've been using my LT3780 power supply for some times, some limitations are showing. In particular : * Cannot set max current to less than ~ 100 mA * Resets if actual current is way above limit , when limit is low * Linear pot, so painful to set low values As far as requirements are concerned, i aim at max ~4A First things first, let's have a closer look at the first stage of our current sensing measure : It is a non inverting  opAmp amplifier , that we'll simplify here that way. It is done on a breadboard using cheap LM358 from ebay (~1$ for 20) Let's drive it from 0 to 14 mV, representing a current sensing from 0 to 2 A The result is as follows, output voltage vs input voltage in mv: We can see the  input voltage offset, it should be ~  2mV according to the datasheet. It is only 0.74 mV here. That graph  can be approximated as VOut = (Iin*7mOhm-0.74mv)*153  (value <0 are grounded) That can also be expressed  as : VO

I've fried 4 of the TP5100 i had. First one is 100% my fault,  i was careless. Not the 3 others. The last one worked fine for ~ 10 mn then fried. The 2 possible explanations i see are :  * They dont like the voltage surge at power up, where input can go higher than the 10v the DC/DC converter has been set to * Using the pin header to drive external leds draws too much current and fries it. That's what i think. Anyway, i'll go back to TP4056 single cell charging, never had any problems with them.