Parameter Measurement Information
Switching Time Waveforms
Note A:The input pulses are supplied by generators having the following characteristics:
PRR ≤ 1 MHz, duty cycle ≤ 50%, ZOUT ≈ 50Ω. For DM74S161/163, tr ≤ 2.5 ns, tf ≤ 2.5 ns. Vary PRR to measure fMAX.
Note B: Outputs QDand carry are tested at tn + 16 for DM74S161, SM74S163 where tn is the bit time when all outputs are LOW
Note C: VREF = 1.5V.
Switching Time Waveforms
Note A: The input pulses are supplied by generators having the following characteristics:
PRR ≤ 1 MHz, duty cycle ≤ 50%, ZOUT ≈ 50Ω. tr ≤ 2.5 ns, tf ≤ 2.5 ns. Vary PRR to measure fMAX.
Note B: Enable P and enable T setup times are measured at tn + 0.
Note C:VREF = 1.5V.
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