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Connecting more than one SMU to the switch matrix

7001, 7002 and Switch Cards
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sesha2007
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Joined: September 21st, 2012, 1:00 am
Country: Germany

Connecting more than one SMU to the switch matrix

Post by sesha2007 » September 21st, 2012, 1:19 am

Hello

We are using Keithley 7002 switch matrix for testing the pins on our IC's with Keithley 2602A SMU. The matrix with all its banks interconnnected to each other works perfectly, when we use single SMU. However for leakage measurements, we need to connect atkeast 2 SMU's, source a constant voltage to one pin on the IC and sweep the other SMU for the leaking pin. How can this be achieved? Since connecting a constant voltage source to the matrix overrides the sweeping SMU.

If the banks of the matrix are separated and we have pins on different banks, then we are able to use different sources for different banks. With this procedure 7002 is no longer a matrix but only a serial switching system. But is it possible to function the system as a Matrix and still supply with 2 different sources?

Thank you for your time and consideration

Regards,
Sesha Kumar.

Jane S
Keithley Applications
Keithley Applications
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Re: Connecting more than one SMU to the switch matrix

Post by Jane S » September 21st, 2012, 11:02 am

Hi Sesha,
What is the function of the constant voltage source? If the pin for the source V is fixed, you can keep the matrix line as your source then use the other SMU channel to test around the IC pins to measure leakage. Basically, you have one matrix line for source V and another line for measure leakage testing around your IC.

sesha2007
Posts: 4
Joined: September 21st, 2012, 1:00 am
Country: Germany

Re: Connecting more than one SMU to the switch matrix

Post by sesha2007 » September 23rd, 2012, 3:28 am

Hello Jane,

Thank you for your reply.

Yes the one of the pin is used as a constant source (Eg. VBus or VDD), then leakage pin has a sweeping voltage. Both these pins have to be selected using 7002 and currently we are using 7011c cards for selection of pins. But once we connect the second SMU, the sweeping no longer works and all the pins are sourced the constant voltage.

Can we achieve the result using a 7012c card?

Regards,
Sesha.

Jane S
Keithley Applications
Keithley Applications
Posts: 114
Joined: November 10th, 2010, 5:45 pm
Country: United States

Re: Connecting more than one SMU to the switch matrix

Post by Jane S » September 24th, 2012, 10:46 am

Hi Sesha,
Yes, 7012-C and 7012-S will be perfect. See datasheet below.
Attachments
7012.pdf
7012-C Datasheet
(124.42 KiB) Downloaded 1143 times

sesha2007
Posts: 4
Joined: September 21st, 2012, 1:00 am
Country: Germany

Re: Connecting more than one SMU to the switch matrix

Post by sesha2007 » September 25th, 2012, 1:08 am

Hello Jane,

I am still not clear with the concept. I looked through the datasheets of 7012c and 7011c.

7012c allows us to connect more than 1 SMU to the matrix. For eg. SMU 1 to Row 1, SMU 2 to Row 2 and so on.We get from any column on row 1 only the source from SMU1, from any column on row2 source from SMU2. Channels will be limited to 10 for each SMU(equivalent to number of columns).

This similar result we are achieving by separating the banks of the muliplexer(removing the jumpers on the card interconnecting the banks) and supplying different sources to different banks. For eg. SMU1 to bank A, SMU2 to bank B and so on. For any switch(column) on Bank A we get source from SMU1, for any switch(column) on Bank 2 source from SMU2. Channels per SMU is again limited to 10.

If this is the case, what is the difference between 7011c and 7012c?

What we want to achieve is to provide source from SMU1 on Row1 Column1 and source from SMU2 on Row 1 Column2. Overall we require 40 channels on the entire card to be able to switched with any of the 4 SMU irrespective of the row they are present on.

Kindly provide a solution, if present.. Thank you for your time.

Regards,
Sesha.

Andrea C
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Keithley Applications
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Re: Connecting more than one SMU to the switch matrix

Post by Andrea C » September 25th, 2012, 5:04 pm

Hi Sesha,

It is sounding like you desire a 4x40 matrix.

The 7012-C is a 4x10 matrix and as you have indicated, you can connect any row to any column.
The 7011-C is a quad 1x10 multiplexer organized in four banks. If the bank to bank jumpers are removed, you have four independent banks.

Here is a diagram from the manual for the 7012-C that shows how you can expand the matrix by the use of the 7011-C card. To get to 4x40, you'd need one 7012-C and three 7011-C.
7012_expanded_7011.bmp
7012_expanded_7011.bmp (620.62 KiB) Viewed 19105 times
Andrea

sesha2007
Posts: 4
Joined: September 21st, 2012, 1:00 am
Country: Germany

Re: Connecting more than one SMU to the switch matrix

Post by sesha2007 » September 27th, 2012, 12:02 am

Hello Andrea,

Yes 4 X 40 Matrix is what I am looking for. I was hoping to achieve this with one card since we were already able to do it with 4 multiplexer cards. The total number of pins we require as a matrix is more than 500 which is around 13 "4 X40" matrix and having so many catds is not a better solution.

Thank you for the reply.

Regards,
Sesha.

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