DC sweep done over several seconds and recorded with a DATAQ data logging module. Closed loop gain set to 21 with 20MegOhms and 100k external resistors.
The power supply was my R100-B, putting out 300V.
Avol varies from unit to unit, depending on the amount of internal positive feedback.
Some units, with too much positive feedback, show a non-monotonic error signal at the inverting input during DC sweep.
This unit shows gains near 1 million for output voltages less than +/-20V, but gain drops off as the rated swing of +/-50V is reached. The internal positve feedback near the center of the transfer function is just right.
Voltage swing exceeds the specified +/-50V specification, but with Avol degradation.
The full scale step response shows a 10V/us Slew rate.
The Full power bandwidth of 40kHz coinsides with the small signal bandwidth of 40kHz with a loop gain of 21.
The small signal gain-bandwidth product of 840kHz at a loop gain of 21 approaches 1MHz.