ask question on Agilent Logic Analyzer 16822A

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I have two signals: clock and data. the swing voltage from 0v to
1.2v. frequency is 33M on clock. I am trying to use Agilent logic
analyzer 16822A to capture the two signals, but the the analyzer
cannot capture the clock signal. I don't know the reason, I could use
oscillascope to see the waveform very easily, but why the logic
analyzer cannot capture the waveform?

Could anyone please give me some help or hints?

many thanks.

mary

 

[Keyser Soze]

Two possible reasons:

1 - Most logic analyzer probe have low input impedance about 100k to 250K
ohms.

Oscilloscope input impedance is usually about 10M ohms. Your circuit may
have trouble driving the logic analyzer input.

2 - Logic analyzer inputs have one voltage threshold.

As the operator you must set the input voltage threshold to about half the
peak voltage your circuit provides. In your case about 0.6 volts.