Hi Dave,
I could not recommend this SMU for chiplevel semiconductor device measurements and I think for general purpose SMU jobs in the board level domain it is too expensive.
The panel show a 10fA number but that is only the resolution. At 10nA range the offset is 50pA or 5000ppm. That is because of the hole design compromize where the high current range MOSFETs present leakage to the output path. That is because I guess the relays are not used to isolate the current ranges. I had issues in the past where the temperature rise in high current range change the gate leakage current impact in a subsequent low current range. That could be fixed by reversing the sequence in testing but makes the device stepping slower. I tought that it would be better to use relays there. Optional these could be inactive by software if speed is prefered.
The second issue is that todays small semiconductors have temperature time constants which are 10-100x faster than 10us. So the curves are distorted by the various temperature effects. These are important only in the higher current range relative to the maximum current of the devices but there is no trade built into the SMU instrument speed versus resolution.
So for semiconductor SMU jobs it is not specific designed for and for discrete device testing it is too expensive.
I have the same opinion, that it is too expensive. I do not thing that banana socket is best chioce for the precision measurement. On 2636 it is much more better, lowest range 100pA. For basic semiconductor characterization is better choice the Keithley picoammeter 6485 which is about 1,5k USD but without supply. Or their dual picoammeter 6482 with integrated supply (30V ) for about 4,5k USD.
Hi Dave,
I enjoy your videos thanks. Those triaxial connectors that are used on the external test enclosure connections are the same that are used on a jet aircraft data distribution bus, ie MIL-STD-1553. i have worked on those in the past. the coax used with them was 78 Ohm. After watching your video i then realized that maybe they were using a similar "guard" screen system on the aircraft. Aircraft power was 400Hz with the chassis the return. but i think the 1553 data bus is a differential system. anyway that is first time i have seen those connectors any where else other than on aircraft. they could be used on land vehicles, space craft etc too...
There is much more triaxial connectors available - not only BNC basis (Fischer, Lemo they have their own solution), the old ones has only two lugs and can be destroyed plugging it to normal BNC, thats why has been made the tri-lug triaxial connector.
For purposes you mentioned were propably used connectors with different insulation materials (cheaper).
I was also quite surprised when I saw the triax during Mike teardown of the Fluorescence Spectrometer. For low level measuremnts should be used only connectors with PTFE insulation.
It is quite similar with cables, you can find the cheap triaxial cable, but it is not useable for low level measuremets in pA range.