General Information—7A42
TABLE 1-2 (CONT)
Electrical Characteristics
Characteristic
Performance
Supplemental
Requirement
Information
TRIGGER (CONT)
EXT
CLOCK
Input
(cont)
Input
Impedance
The
EXT
CLOCK
INPUT
may be connected
directly to
the
clock
source,
or
through a 1X
probe
(TTL
only).
The
EXT
CLOCK Input
is
not
compatible
with
a
10X
probe.
TTL
Level
Approximately
10K
ohm
in
parallel
with
approximately
55
pF,
terminated
to
+5
V.
ECL
Level
Approximately
50
ohms,
terminated
to
-2
V.
Minimum
Input
Slew
Rate
TTL
Level
None.
ECL
Level
100
mV/ns.
Pulse Width
TTL
Level
20
ns
minimum.
Either
pulse
transition
selected.
ECL
Level
5
ns minimum.
Leading
pulse
transition
selected.
10 ns
minimum.
Trailing
pulse
transition
selected.
Set-up Time
10
ns
minimum.
Time
that
level
sensitive
channels
must
be valid
before
EXT
CLOCK
INPUT
transition.
1-15
