Cap measurement time for PXI-4072 300pf range; + time to switch PXI-2530

[pkrat@atmel]

We are evaluating using the pxi-4072 along with the pxi-2530 multiplexor to measure ~ 82pf tuning caps on die during wafer probe.  We would be running a X16 probe setup so I am interested in the single measurement time for this on the pxi-4072 and also the time to switch the 2503 to the next dut for measurement.  I.E. how long would it take to measure 16 duts.   Depending on the additional test time this could be a viable solution / replacement.  The operating system is XP on our testers.  Not sure if this is germain to the question.

Thanks,

PKrat

[HeatherBaker]

 Hi,

See the image below.  These are taken from benchmarking results performed by R&D.  Although they are not officially spec'd we have seen these numbers as fairly common.  Scan rate depends on the digits of precision of your DMM, so unless you are reading 6 digits of precision, then you the measurement should take less than a second.

Also take a look at Benchmarking Reading Rate and Resolution This can be executed in simulated mode, which uses the Initialize with Options VI to simulate the reading.  Executing this VI should give you an estimate of how long it will take to acquire one measurement.

Hopefully this helps!

[pkrat@atmel]

Thanks for the response.  If I interpret this correctly we would only need the PXI-2503.  With 4 digit precision we would be able to do up to 100 measurements in one second.  With 5 digit up to 90 / second. Is this correct?  Either of which would easily perform our 16 dut measurements in under 100ms.

Also as a side question - can you synchronize two PXI-5402 function generators to produce a differential signal on two lines, or is there a single function generator that can do this.  We would need a 13.56Mhz signal.  Can it be multiplexed to drive 16 duts at a time.

Thanks,

Paul

[HeatherBaker]

According to the benchmarked results, it would take approximately 160ms at 4.5 digits of precision and 178ms at 5.5 digits of precision. 

[Aaron_W.]

Paul,

As far as your side questions goes, the PXI-5402 devices have the ability to use our T-CLK VIs which would allow you to synchronize these devices together, so you could produce a differential signal, you would have to configure the two individual waveforms however.  What type of signal are you wanting to generate?

We do have a function generator that does differential, but it is for IQ signals. The device is the PXI-5450.

If you could tell me a little more about what type of waveform you need. As far as the multiplexing across 16 DUTs, it would greatly depend on the power levels that these DUTs would need. Could you give some more information on these?