After working with users that changed their LPS and had problems with the M2Nano’s USB connection I wanted to know:
- How much current does the M2Nano draw??
This is important in that some LPS’s 5V are very limited in capacity (20ma) and my not be able to be used to power a M2Nano.
I dont like to just guess on things like this.
Not being able to get a direct answer from any source of M2Nano specs it occurred to me there may be an indirect way to estimate the M2Nano max current draw.
That is, by considering the stock configuration of a K40. In a stock K40 the LPS’s 5V output drives the Nano and I know something about the internals of K40 LPS.
You can see from the schematic below that the stock LPS provides 5V power from a 7805
From the TI LM7805 data sheet:
I found output current specs on LM7805 devices ranging from 1 - 1.5 amps depending on the vendor.
I physically checked one of my test LPS. It had a 7805H installed
- It seems reasonable to estimate that the current draw of the M2Nano to be less than 1.5A
- A 2A @ 5V supply seems like a safe design point and should have enough capacity to power a M2Nano.
An incidental finding while looking for M2 Nano specs for 5V power supply load.
I do not recall seeing this info posted anywhere.