Test Circuitry (ECL-to-TTL)
DS100295-10
=
50Ω termination. When an input or output is being monitored by a scope, R is supplied by the scope’s 50Ω resistance. When an input or output is
t
Note 20:
R
t
not being monitored, an external 50Ω resistance must be applied to serve as R .
t
Note 21: The TTL TRI-STATE pull up switch is connected to +7V only for ZL and LZ tests.
Note 22: TTL and ECL force signals are brought to the DUT via 50Ω coax lines.
Note 23:
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)
DS100295-11
Note 24: DIR is LOW, and OE is HIGH
FIGURE 4. ECL-to-TTL Transition — Propagation Delay and Transition Times
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