eriksl wrote:The drawback from using only a buck converter is that it needs to be set to 3.3 V very carefully using a very small trim pot. When finally on the spot, it can easily set off-spot due to dust, shocks etc. And then it may give a voltage way too high for the esp, destroying it. That's why I like to have a fixed lineair regulator in between.
There is a great little switching regulator board out of China called mini360. I have used it in a number of products I have designed. It uses a trim pot. But I have that removed and replaced with a fixed resistor for the same reason as you stated.
I imaging some customer having a problem with the product and him going in and turning it to try and make it work. In the past when I have needed to us trim pots I have had production use nail polish to lock the position in place.
I am using all the time fixed value resistors calculated for the desired Voltage output.
In more than 25 years of playing with I have seen more catastrophic Linear regulators failures than SW ones.
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