Digital Multimeters (DMMs) and Precision DC Sources

cancel
Showing results for 
Search instead for 
Did you mean: 

PXIe-4163 current_limit_autorange seems doesn't work for low level current

Solved!
Go to solution

Hi guys,

these days i was doing some MOSFET idVg curves sweeping using PXIe-4163, as we know, for NMOS, when Vg is about 0 volt, id is very small, saying maybe 1nA or below, it turns out to several mA when Vg gets larger and larger. So I choose current_limit_autorange to switch ranges in measuring.
I found that the current resolution is not as low as my expect. When I use the fixed current_limit_range(set to 100e-9A), I got several hundred pA to several nA, but 10e-7A for current_limit_autorange.

0 Kudos
Message 1 of 9
(3,313 Views)
Solution
Accepted by topic author Onezhenji

FYI - auto-ranging is not a hardware feature but a driver feature. Enabling Auto-Ranging will let the driver choose the current range to follow the current limit setting.

 

You need to use an advanced SMU targetted for device testing like PXIe-4137 that uses hardware-level auto-ranging.

 

 

Santhosh
Soliton Technologies

New to the forum? Please read community guidelines and how to ask smart questions

Only two ways to appreciate someone who spent their free time to reply/answer your question - give them Kudos or mark their reply as the answer/solution.

Finding it hard to source NI hardware? Try NI Trading Post
0 Kudos
Message 2 of 9
(3,304 Views)

I do find a parameter called "autorange" in python's API of nidcpower, it seems that PXIe 4163 doesn't support this parameter.
So, 4163 can't satisfy my measurement requirements, right?

0 Kudos
Message 3 of 9
(3,213 Views)

Is there any way I can use PXIe 4163 to achieve my measure requirements in my topic?

0 Kudos
Message 4 of 9
(3,242 Views)

Yes, you can implement auto-ranging in software.

 

For every measurement,

  • Make a measurement at a higher range
  • Check measurement against the list of available ranges
  • Choose a range that suits the measurement value
  • Re-measure at the new smaller range
  • After the measurement is done, go back to the larger range
Santhosh
Soliton Technologies

New to the forum? Please read community guidelines and how to ask smart questions

Only two ways to appreciate someone who spent their free time to reply/answer your question - give them Kudos or mark their reply as the answer/solution.

Finding it hard to source NI hardware? Try NI Trading Post
0 Kudos
Message 5 of 9
(3,210 Views)

Well, it seems that I can not use sequence mode.

0 Kudos
Message 6 of 9
(3,198 Views)
Solution
Accepted by topic author Onezhenji

Nope, software-level auto-ranging cannot work with sequence mode as the selection of the best range happens in the application and not on hardware.

Santhosh
Soliton Technologies

New to the forum? Please read community guidelines and how to ask smart questions

Only two ways to appreciate someone who spent their free time to reply/answer your question - give them Kudos or mark their reply as the answer/solution.

Finding it hard to source NI hardware? Try NI Trading Post
0 Kudos
Message 7 of 9
(3,172 Views)

I updated nidcpower to the 2022 Q4 version, now PXIe-4163 supports auto-range. Thank u.

0 Kudos
Message 8 of 9
(2,965 Views)

@Onezhenji wrote:

I updated nidcpower to the 2022 Q4 version, now PXIe-4163 supports auto-range. Thank u.


Good to know that the latest driver updates the SMU firmware to support hardware level auto-ranging

Santhosh
Soliton Technologies

New to the forum? Please read community guidelines and how to ask smart questions

Only two ways to appreciate someone who spent their free time to reply/answer your question - give them Kudos or mark their reply as the answer/solution.

Finding it hard to source NI hardware? Try NI Trading Post
0 Kudos
Message 9 of 9
(2,957 Views)