Test Circuitry (ECL-to-TTL)
DS100306-10
=
50Ω termination resistive load. When an input or output is being monitored by a scope, R is supplied by the scope’s 50Ω input resistance. When
T
Note 18:
R
T
an input or output is not being monitored, an external 50Ω resistance must be applied to serve as R
Note 19: The TTL TRI-STATE pull-up switch is connected to +7V only for ZL and LZ tests.
Note 20: TTL and ECL force signals are brought to the DUT via 50Ω coax lines.
.
T
Note 21:
V
is decoupled to ground with 0.1 µF, V is decoupled to ground with 0.01 µF and V is connected to ground.
EE CC
TTL
FIGURE 3. ECL-to-TTL AC Test Circuit
Switching Waveforms (ECL-to-TTL)
DS100306-11
Note: DIR is LOW, OE is HIGH
FIGURE 4. ECL-to-TTL Transition — Propagation Delay and Transition Times
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