100329
Test Circuitry
(ECL-to-TTL)
Note 14:
R
T
=
50Ω termination resistive load. When an input or output is being monitored by a scope, R
T
is supplied by the scope’s 50Ω input resistance.
When an input or output is not being monitored, an external 50Ω resistance must be applied to serve as R
T
.
Note 15:
The TTL 3-STATE pull-up switch is connected to
+7V
only for ZL and LZ tests.
Note 16:
TTL and ECL force signals are brought to the DUT via 50Ω coax lines.
Note 17:
V
TTL
is decoupled to ground with 0.1
µF,
V
EE
is decoupled to ground with 0.01
µF
and V
CC
is connected to ground.
FIGURE 3. ECL-to-TTL AC Test Circuit
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