Analog
Section
Figure
4-3
shows
the
analog
section
block
diagram.
The
4339B
analog
section
can
be
divided
in
two
sections
,
the
dc
voltage
source
section
and
the
ammeter
section.
The
dc
voltage
source
section
applies
measurement
voltage
to
the
series
circuit
consisting
of
the
DUT
and
I-V
Converter
.
The
DUT
is
connected
to
the
4339B
\Input"
connector
by
a
triaxial
cable
which
is
a
three
layered
coaxial
cable
.
This
triaxial
cable
sheilds
external
noise
and
improves
the
contact
check
function
accuracy
.
The
current
ows
into
the
I-V
Converter
in
the
ammeter
section
via
the
contact
check
transformer
.
As
discussed
in
\I-V
Converter",
the
I-V
Converter
converts
current
owing
into
to
voltage
ramp
.
The
normalization
amplier
enhances
the
number
of
measurement
range
and
of
measurement
speed
selection
with
fewer
range
capacitors
.
The
I-V
converter
output
voltage
slope
,
which
is
proportional
to
the
converter
input
current,
is
determined
by
the
dierence
between
two
voltage
measurement
results
in
a
certain
time
interval.
The
result
(current)
is
converted
to
digital
data
by
the
ADC,
and
transferred
to
the
CPU
section
by
optical
ber
links
.
Figure
4-3.
Analog
Section
Block
Diagram
T
roubleshooting
4-5
