Tektronix Technical Forums are maintained by community involvement. Feel free to post questions or respond to questions by other members. Should you require a time-sensitive answer, please contact your local Tektronix support center here.

Ids-Vds with external power supply

6514, 6517 Support
Post Reply
oussalah
Posts: 10
Joined: January 17th, 2021, 9:21 am
Country: Algeria

Ids-Vds with external power supply

Post by oussalah » June 16th, 2021, 5:51 am

Hi,
I would like to characterize à transistor and obtain the transistor characteristic curves. How to plug an external power supply on the gate of the transistor.
Thanks
Attachments
Keithley6517B for Transistor.jpg
Keithley6517B for Transistor.jpg (83.76 KiB) Viewed 125 times

Andrea C
Keithley Applications
Keithley Applications
Posts: 1578
Joined: October 15th, 2010, 10:35 am
Country: United States
Contact:

Re: Ids-Vds with external power supply

Post by Andrea C » June 16th, 2021, 3:46 pm

On the rear panel of the 6517B, the VSource has red and black banana.
Plug the LO of your power supply into the black banana of the VSource.
Connect the power supply HI to the Gate.

This creates the following:
PS_6517B.PNG
PS_6517B.PNG (18.93 KiB) Viewed 119 times
The power supply voltage is applied across the Vgs of the DUT and the Amp meter. But the voltage burden of the amp meter is at most 5mV if using 20mA range. If power supply applies 1.000 V, the Vgs will only be 0.995 if the Amp meter voltage burden is the full 5mV. For smaller currents, the voltage burden is smaller and a less significant reduction in Vgs will occur.

oussalah
Posts: 10
Joined: January 17th, 2021, 9:21 am
Country: Algeria

Re: Ids-Vds with external power supply

Post by oussalah » June 17th, 2021, 3:27 am

Thank you.
The power supply is a TTI CPX400D.
My concern is about the connection between the LO of the Keithley 6517B voltage source and the OUTPUT(-) of the external power supply.
Knowing that the LO of the 6517B is a floating connection whereas the OUTPUT(-) of the external power supply is also (another) a floating connection.
Is there no damage when connecting LO(6517B) and OUTPUT(-) of the TTI CPX400D.

oussalah
Posts: 10
Joined: January 17th, 2021, 9:21 am
Country: Algeria

Re: Ids-Vds with external power supply

Post by oussalah » July 28th, 2021, 7:01 am

Could you show me how to connect the external power supply when the transistor is a N-JFET (transistor with n channel) where I must bias the gate with negative values.
Attachments
Q_Kei5617B_connection with PS_4.jpg
Q_Kei5617B_connection with PS_4.jpg (59.04 KiB) Viewed 46 times

Andrea C
Keithley Applications
Keithley Applications
Posts: 1578
Joined: October 15th, 2010, 10:35 am
Country: United States
Contact:

Re: Ids-Vds with external power supply

Post by Andrea C » July 30th, 2021, 4:30 am

The power supply model number you identified seems to be a floating power supply.
This is good. This means you can think of the power supply signal that you will use for the Gate of the transistor as a battery.
If the power supply is outputting 1V, it is not true that one terminal is at ground and other is at 1V. Instead, it is true that there is 1V of difference between the two terminals. Is also true that the negative terminal is at lower potential than the positive terminal.

To apply negative Vgs signal to the JFET:
Id-Vds_6517B.PNG
floating Vgs to apply negative Vgs to JFET
Id-Vds_6517B.PNG (35.35 KiB) Viewed 34 times

Post Reply

Return to “Electrometers”

Who is online

Users browsing this forum: No registered users and 2 guests