Fluke 93 Service Manual page 55

CIRCUIT
DESCRIPTIOMS
3-21
Schematic Diagram
AASK:
OCX)30d
COAT CCLK DTAE
Figure
3.
12 Schematic
diagrarrt
A-
ASIC D2301
Channet
Se/eetor
The
channel
selector selects
channel
A
or
channel
B.
depending on
the
level
of the
GHANA
signal
(Input13).
If
CHA
is "high*'
(> 3.5 V)
channel
A
Is
selected.
If
CHA
is
"low" (< 1.5
V) channel
5
is
selected.
If
a timebase speed
faster
than
20
|xs is
selected, both
channels
are displayed
In
alternate
mode and
CHA
is
a square
wave
signal with
a timebase-dependent frequency
(see table
3.7).
If
a
timebase
speed
slower than
50 ps
is
selected,
both channels are displayed
In
chopped mode. The
CHA
signal
is
a
square
wave
signal with
a
trigger-dependent frequency
of
500
kH
2
maximum.