Bug #270

K2 : ERROR 304.7 - Ohms sources; 4.4nA and 770nA

Added by tin about 7 years ago. Updated over 4 years ago.

Status:ClosedStart date:18/07/2012
Priority:NormalDue date:
Assignee:tin% Done:

0%

Category:-
Target version:Keithley 2001 #2

Description

Cannot measure 2.2V ±0.6V at A/D IN.

This test uses the same ohms source resistor (R354) as the previous test except that analog
switch U323 (/200M pulled low) is closed to conÞgure Op Amp U324 into a divide
by 16 ampliÞer. This reduces the voltage drop cross R354 from 7V to 0.44V (7/16 =
0.44). 4.4nA is sourced through R394 to common through Q328. Op Amp U322 is set up
for x50 gain. Measure 2.2V at A/D IN.

Suspect:
U323, R350, R349 and R215.

History

#1 Updated by tin about 7 years ago

  • Category set to 60
  • Target version set to Keithley 2001 #2

#2 Updated by tin over 4 years ago

  • Status changed from New to Resolved

#3 Updated by tin over 4 years ago

  • Status changed from Resolved to Closed

Also available in: Atom PDF