Negative Voltage Follower

Thread Starter

baseball07

Joined Apr 24, 2007
39
Hi everyone. Can a voltage follower be configured for negative voltages rather than positive ones? Say, instead of Vin=Vout=2V, have vin=vout=-2V. Thank you.
 

thatoneguy

Joined Feb 19, 2009
6,349
Yes, if you have the required power supplies for the circuit, either dual polarity or "positive ground".
 

Papabravo

Joined Feb 24, 2006
12,301
Hi everyone. Can a voltage follower be configured for negative voltages rather than positive ones? Say, instead of Vin=Vout=2V, have vin=vout=-2V. Thank you.
What makes you think a follower won't follow negative voltages?
 

alphacat

Joined Jun 6, 2009
186
To the OP
You just need to worry about the bias point of the transistor.
If you insert a negative input DC voltage, then you need to make sure that the VEE (or VSS) of the circuit is negative enough in order to have VBE =~ +0.7V (or to have VGS > VTn).
 
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