Considerations Using the SET Curve Tracer Amplifiers
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                                       Rev. Date:  18-Jan-2021


1. Once you start the cool down  I would keep the power
   turned ON to the amplifiers at all times.  That is, let
   the amplifiers self heat at all times.  These amplifiers
   include bipolar transistors and if they get cold enough
   to freeze out their minority carriers it  could be  that
   the amplifiers will not be able to power back up.


2. Never turn ON the Bias Supplies  (especially the
   Offset from Ground Bias Supply)  without first having
   turned ON the amplifier power.


3. The amplifier inputs are very static sensitive -
   I would always use an ESD protection wrist strap
   when connecting the amplifier inputs.


4. Points about the Yokogawa GS200 supplies for SET Bias:

   The GS200 supplies include an internal Guard that can
   be connected to either the front panel Output Low
   terminal  or  to a front panel Guard terminal.

   In the Yokogawa manual this is described as Guard ON
   or Guard Off:

   Guard ON  ---> Guard is connected to the Output Low terminal

   Guard OFF ---> Guard is connected to its own  Guard terminal

   See the Yokogawa manual pages:  2-10,  4-5,  4-6,
   and the block diagram in Appendix 2.

   I think that you want the internal Guard connected to its
   own Guard terminal.  This should provide the lowest noise.
   The Guard in each GS200 supply is then carried by the
   Shield on its own twisted pair Bias Supply cable to the
   common ground point on the cryostat port where the SET
   Curve Tracer Instrumentation Amplifiers are located.

   Note that connecting the Guard on the S-D Bias supply
   to the Output Low terminal of that supply will short
   circuit the output of the Offset from Ground Bias supply.

   See drawing #17  in the web directory:

   https://web.pa.msu.edu/people/edmunds/SET_Curve_Tracer/Drawings/

   You should not need to set the current limit for these
   SET Bias supplies to more that a few mAmps.


5. The inputs to the SET Curve Tracer Instrumentation
   Amplifiers are two SMA connectors that are mounted on
   a bracket located just below the Inst Amps.

   The SMA connection to the positive input of the voltage
   signal amplifier and to the current signal amplifier
   along with its 100k Ohm shunt is labeled with a "D" to
   indicate the Drain terminal of the SET.

   The SMA connection to the negative input of the voltage
   signal amplifier is labeled with a "S" to indicate the
   Source terminal of the SET.

   These connections are seen as the double arrows in
   drawings #26  in the web directory listed just above.

   The outer shells of both SMA connectors are tied to the
   ground planes in the Instrument Amplifier circuit boards
   and from there to the common ground point on the cryostat
   port where these amplifiers are located.