How to design a level shift that shift voltage from 0~3.3v to 1.7v~5v

[incol]

I know how to shift the vdd voltage from 3.3v to 5v, but don't know how to shift ground voltage from 0v to 1.7v, does ot need LDO? or any other approachs?
BTW, the 1.7v ground should sink 20mA current.

Thanks

 

[BradtheRad]

Here are two simple ways:



The left-hand schematic assumes your incoming signal will sink 20mA. I gave it a 6V supply as a kludge in order to bring the output up to 5V.

The right-hand schematic is only a rough draft. It will take a second transistor to restore original polarity of the incoming signal. The 5V supply represents either (a) the power supply, or (b) the following stage which sources 20mA as you specify.

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