Bug #270
K2 : ERROR 304.7 - Ohms sources; 4.4nA and 770nA
Start date:
07/18/2012
Due date:
% Done:
0%
Estimated time:
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.