28 volt buffer?

Thread Starter

chris13409

Joined Jan 7, 2010
7
What device do I need? I need to buffer some logic levels so they can be sent to a PIC. They vary between 7 to 28 vdc. Is there a buffer that can tollerate 28vdc while drawing very little current The output voltage from the buffer can be anything from 1 to 5 vdc.
 

mik3

Joined Feb 4, 2008
4,846
You can use an op amp voltage follower with the signal fed to its input. If you want to reduce the output voltage use a voltage divider.
 

SgtWookie

Joined Jul 17, 2007
22,201
What kind of tolerance do you have on the translator current?

You might use a resistive divider and a comparator.
 

Bernard

Joined Aug 7, 2008
5,227
Look at MM74C914, schmitt trigger with extended input voltage. Might be close.
 

rjenkins

Joined Nov 6, 2005
1,015
For logic inputs, a simple resistive divider will work fine.

Three resistors connected to a junction point; 2k2 from the input, 4k7 to ground(0V) and 100K to the PIC input pin.
 

Thread Starter

chris13409

Joined Jan 7, 2010
7
Thanks guys,

I think the MM74C914 might do it. These are fault signals, and I usually check them with a multimeter. (I should have said that in the first place.)
I'm not sure I can use a voltage divider because it'll draw too much current from my system.

Chris
 
Top