Dear TI:
My customer want to know the test standard of propagation delay time. Is it from 50% of the rising edge of the input signal to 50% of the rising edge of the output signal? Or from 100% of the rising edge of the input signal to 100% of the rising edge of the output signal?
Thanks!
Regards!
Eric
Hi Eric,
The propagation delay is defined as the time between the specified reference points on the input and output voltage waveforms, with the output changing from one defined level (high or low) to the other defined level (tpd = tPHL or tPLH).It is generally defined as the time between the 50% point of the input pulse to the 50% point. The input pulse is usually crossing the reference threshold at 50%.
The propagation delay is the calculated RC time constant of the typical on-state resistance of the switch and the specified load capacitance, when driven by an ideal voltage source (zero output impedance)
The propagation delay spec in the SN74LV4053A datasheet refers to test circuit in Fig 4.
As you see from the test circuit, the rise and fall times depend on load conditions on the output of the device.
Thanks
Saminah
