Re: Differential probe design - BANDWIDTH ? ? ?

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Malcolm Watts by way of Terry Fritz <teslalist-at-qwest-dot-net>" <m.j.watts-at-massey.ac.nz>

Hi Terry,
           The closed-loop gain of that circuit appears to be unity or
near-as. In effect, the input signal is being fed into a voltage
divider.

Malcolm

On 16 Jul 2003, at 18:45, Tesla list wrote:

 > Original poster: "Terry Fritz" <teslalist-at-qwest-dot-net>
 >
 > Hi Malcolm,
 >
 > At 11:10 AM 7/17/2003 +1200, you wrote:
 > > > >Terry,
 > > > >
 > > > >What kind of bandwidth are you getting with your differential probe
 > > > >design?  Did you simulate it at all?
 > > >
 > > > It has never been built...  The ICs go to 150MHz.
 > >
 > >What is the target gain of the circuit at what -3dB frequency? The
 > >150MHz thing will be -3dB -at- unity gain.
 > >
 > >Malcolm
 > >
 >
 > The gain is 0.001 ;-))  But probably would us the unity gain numbers in our
 > case.  We could really get by fine with 1MHz bandwidth.  Here is my
 > "original" TL082 circuit:
 >
 > http://hot-streamer-dot-com/temp/DiffProbe01.gif
 >
 > But everyone wanted far better common mode rejection and higher
 > frequency.  So I am pushing it for all it's worth ;-))
 >
 > Cheers,
 >
 >          Terry
 >
 >
 >