Products > Test Equipment
Keithley 2400 SourceMeter review and teardown
<< < (12/24) > >>
VintageNut:

--- Quote from: ivonenand on January 02, 2017, 11:38:26 am ---Hi guys,
Does anyone know, how the output current sense is implemented in this SMU (or any other for that matter)? The thing is, you need extremely high CMRR, since the output is anywhere in the +-200V range. Second, the SMU offers better than 1uA resolution, so there must be little or no leakage on the amplifier connected to the output shunt. You cannot do that with a standard differential amplifier.

Any ideas on how the amplifier connected to the output shunt is implemented?

Regards,
Ivo

--- End quote ---

I do not have a schematic for the 2400. My assumption is that the 2400 is not far from the 238 as far as architecture. The 238 schematic exists as a printed document.
plesa:

--- Quote from: ivonenand on January 02, 2017, 11:38:26 am ---Hi guys,
Does anyone know, how the output current sense is implemented in this SMU (or any other for that matter)? The thing is, you need extremely high CMRR, since the output is anywhere in the +-200V range. Second, the SMU offers better than 1uA resolution, so there must be little or no leakage on the amplifier connected to the output shunt. You cannot do that with a standard differential amplifier.

Any ideas on how the amplifier connected to the output shunt is implemented?

Regards,
Ivo

--- End quote ---

Check this thread, where is link for schematic of one of Keithley SMU.
https://www.eevblog.com/forum/testgear/keitley-236-teardown-and-review/
2400 is quite similar ( at least output stage, which use the same transistors.
plesa:
Unbelievable repair  :)

julian1:
I did a repair on a 2420 which had burnt power mosfets driving a secondary DC-DC SMPS. The interesting difference with the 2400, is that the power-board and digital board are combined. In contrast, the 2400 uses a third-party non-Keithley power board.

The same pcb is used for the 2430 as well (the silkscreen has a tickbox)- and possibly other high-current output models. Here's a pic of the board,

z01z:

--- Quote from: plesa on March 12, 2017, 04:30:08 pm ---Unbelievable repair  :)


--- End quote ---
It is :)
Then bumped into a video on youtube from , about a secret menu in K2400.
Navigation
Message Index
Next page
Previous page
There was an error while thanking
Thanking...

Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod