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Sharing data between a 5V device and a 3.3V device

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I have a microcontroller and am considering buying a radio module. Every module I find online has a maximum operating voltage of 3.9. My microcontroller runs at 5V.

I want to be able to exchange data between both devices but I'm afraid if I hook up the pins directly then I'd blow up the radio module since it can't handle 5V.

I heard about level converters but I'm not sure which IC to buy. I'd rather buy something that's commonly available.

I also thought of a LDO voltage regulator from 5V to 3.9V to drive VCC of the radio module but I don't know if that's efficient.

Can someone point me in the right direction? I'm also limited to DIP IC's since I don't work with smd.


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Plus a 3.3V regulator to power the 3.3V radio module from the 5V supply the microcontroller uses.

μC+5Vpower-------------------------Vreg--------------------------+3.3V radiopower

μCdatalines----------------------LevelshifterIC---------------------radio datalines


Well-Known Member
3.3V logic can drive 5V logic, check 5V part VIL and VIH. Some 3.3V parts can tolerate 5V inputs, check your radio module data sheet. The data sheet should list maximum input. In many cases no level translation is needed.
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