Shifting 3V3 to 5V

Thread Starter

lexected

Joined Jul 8, 2014
3
Hello!

I've got a bit of a dumb question. I'm using LTSpice for simulation of simple shifter which takes 0V or 3.3V as input and gives 0V or 5V as output. Here's my scehmatic (the image is way too large): http://i62.tinypic.com/16jrjmw.jpg .

When doing simulation I view the voltage on R2 and it's -4.7V instead of +4.7V or +5V.
What am I doing wrong? What must be changed to get positive voltage on R2?

Thanks.
 

ScottWang

Joined Aug 23, 2012
7,397
1. Please upload your circuit to the forum of this website.
2. When you drawing the circuit, put the positive on the upside and put the negative on the downside is better.
3. Please refer to the following circuit of fig-07.


You can using the value of resistor you like.
 

Thread Starter

lexected

Joined Jul 8, 2014
3
ericgibbs, ScottWang, thank you both for your answers.

Using batteries was my intention. I'm bit confused about the source-ground thing, I always used to connect ground to the negative terminal of battery. fig-07 was actually my source and I tried to remake it to use battery.

Can I freely connect Vcc to battery+ and gnd to battery- without doing anything wrong? If not, what can I use as ground? Some big piece of iron?
 

ericgibbs

Joined Jan 29, 2010
18,766
hi lex,
Ground/0V/Common are often used to mean the same thing.

If you use batteries for my level shifter , connect both Negatives together as the Common/0V line.

Scotts circuits are not level shifters, but 'driver circuits'

E

EDIT:
Look at this edited circuit that shows a 0V Comm, Ground

An 'Earth' connection is something different from Ground.
 

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