To Next Page

To Previous Page

Test 100.2 — A/D

Bank A/D

Inputs Open

Expected Value <none speciﬁed>

Limits 100 counts

Fault Message SIGNAL NOISY

Description

This test has the identical setup as the 100.1 test. Signal LO is connected

to the A/D circuit for ten readings and a min/max comparison is done to en-

sure that all readings are within 100 counts of each other. The test is to check

for noise. The failures are the same as in test 100.1.

Primary checks should be the references and power supplies. Secondary

tests are the op amps of the integrator (U138 and U137), gain op amp U142,

and the zero-cross comparator U145.

Bit patterns

Bit pattern Register

87654321

—U106—

110v1111

87654321

—U109—

00101111

87654321

—U134—

1v10000v

—U130—

11111101

87654321

—U121—

01110010

ACDC_STB

MUX_STB

IC pins: Q8=11, Q7=12, Q6=13, Q5=14, Q4=7, Q3=6, Q2=5, Q1=4

2-24 Troubleshooting

Keithley 2000 Repair Manual

Other manuals for Keithley 2000