[doobooloo]

Hello,

Is it possible to run the AD8066 in a simple buffer/voltage follower configuration without a feedback resistor but instead the negative input connected directly to output?

This is what I'm talking about (voltage follower):

Thanks in advance!

 

[DaKi][er]

Yes, the 8066 is unity gain stable

 

[doobooloo]

So all unity gain stable opamps can be run in this buffer config without any feedback resistors?

 

[amb]

Quote:

Originally Posted by doobooloo So all unity gain stable opamps can be run in this buffer config without any feedback resistors?

Basically, yes for any unity-gain stable voltage feedback opamps, when running as a voltage-follower. However, many bipolar-input opamps will benefit from a resistor in the feedback loop of an appropriate value to balance the equivalent resistance at the noninverting side for minimum DC offset.

 

[DaKi][er]

All voltage feedback opamps, which this is
Current feedback usually needs some feedback resistor, though the datasheets will make that very clear if so

 

[ppl]

it is allways best to place a resistor from the op amps output to its inverting input regardless of the type of opamp CFb or VFB. A CFB opamp requires this resistor for stability and as sutch you can not simply connect a wire from output to -IN with CFB type as you can with VFB op amps. However the resistor is an advantage with VFb also, one reason is the balancing of input resistences AMB talked about and in addition the resistor serves to buffer the large capacitence upon the output from the inverting input and adds stability. anoter often unused reason is by placing a small capacitor across this resistor you can obtain phase lag compensation with unity closed loop gain. so populer with designers