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???
04/12/11 18:17
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 		 #181830 - Another scheme...
Responding to: ???'s previous message
Here is another scheme using modern, fast single supply OPamps:



The circuit was simulated with OPA353 but will also work with OPA2320, AD8616, etc.

Single supply OPamps loose specifications when emitting voltages at the output near 0V. To avoid trouble the negative supply pins are pulled down to about -0.3V. A simple Schottky diode biased by a current of 10...20mA can easily provide this auxiliary potential. If you have a -5V supply voltage drive the Schottky by a 250...470R resistor and put a 100nF cap in parallel to the diode.

To achieve a wide bandwidth and high linearity at highest frequencies the gain is distributed over three stages. The small caps in the feedback loops of OPamps prevent ringing caused by unavoidable input stray capacitances of Opamps. Slowlier Opamps do not really need them, but faster and fastest do!

Kai Klaas

List of 42 messages in thread
TopicAuthorDate
Signal Conditioning!            01/01/70 00:00      
   AC-coupling don't work to 0Hz and kills DC info            01/01/70 00:00      
      subtracting 8.4V            01/01/70 00:00      
         Also question if 8.5V is guaranteed lowest input.            01/01/70 00:00      
            Is Instrumentation Amplifier is good choise?            01/01/70 00:00      
               Instrumentation Amplifier or op-amp            01/01/70 00:00      
                  Thanks Erik            01/01/70 00:00      
   A scheme using the OP-27...            01/01/70 00:00      
      Kai,You are always Positive!            01/01/70 00:00      
      Another scheme...            01/01/70 00:00      
         Take care with OPA2743...            01/01/70 00:00      
            Thanks Again Kai            01/01/70 00:00      
         -5 Volt Supply            01/01/70 00:00      
            Again            01/01/70 00:00      
               Wrong            01/01/70 00:00      
                  No,only 2 questions!            01/01/70 00:00      
                     Two answers...            01/01/70 00:00      
                        Thank you very much dear Kai            01/01/70 00:00      
         a question?            01/01/70 00:00      
      Please Tell Me your Comments!            01/01/70 00:00      
         ?            01/01/70 00:00      
            Yes,kai            01/01/70 00:00      
               Differential signaling            01/01/70 00:00      
                  Some Questions!            01/01/70 00:00      
                     Precision            01/01/70 00:00      
                        Thanks Per,            01/01/70 00:00      
                     Some answers...            01/01/70 00:00      
                        factor of 4            01/01/70 00:00      
                           Don't forget the subtracting scheme!            01/01/70 00:00      
                        kindness            01/01/70 00:00      
                        Deduction!            01/01/70 00:00      
                           Correct            01/01/70 00:00      
                        nature of signal!            01/01/70 00:00      
                           I'm sorry?            01/01/70 00:00      
                              A bit more            01/01/70 00:00      
                                 This is your signal?            01/01/70 00:00      
                                    I have said this in the first post            01/01/70 00:00      
                                       Any link?            01/01/70 00:00      
                                          calibrating,            01/01/70 00:00      
                           Is there a datasheet in english?            01/01/70 00:00      
                              No,i have searched very much            01/01/70 00:00      
            DYNAMIC RESPONSE            01/01/70 00:00      

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