HP 8340b - A62 Motherboard Overall Description

A62
Motherboard
Overall
Description
ASSEMBLY
PURPOSE
The
A62
motherboard
is
the
common
board to
which
many
other
assemblies
are
connected
and
serves
to
route
signals
between
these
assemblies.
The
A62
motherboard also
routes
signal
to and
from
the
front/rear
panel
connectors.
GROUNDS
The
A62
motherboard
has
several
different
grounds:
•
STAR
GND
—
is
the
single
ground reference
point
for analog
circuitry
in
all
major assemblies.
Each
assembly
block
is
referenced
to
STAR GND
via
individual
traces,
minimizing
ground
noise
crosstalk
between
major assemblies.
STAR
GND is
a
screw
terminal
located
between
the
A62XA57
marker
bandcross
connector
and
A62J3
connector
and
is
visible with
the
instrument top
cover
removed.
•
GND
—
designates
individual
analog ground traces connecting
major
assembly
blocks
to
STAR
GND. Many
of
these traces
are
physically
large and
are
used
for
high
current
power
supply
applications.
•
GND
PLANE
-
Refer
to
Figure
E-1.
Figure E-1.
A62
Motherboard
Cross
Section
ANALOG SIGNALS
DIGITAL GROUND PLANE
DIGITAL
SIGNALS
DIGITAL
SIGNALS
DIGITAL GROUND PLANE
ANALOG
SIGNALS
HP 8340B/41B
A62
Motherboard
Overall Description
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