Trigger Mode/Coupling 11
Agilent InfiniiVision 3000 X-Series Oscilloscopes User's Guide 185
The external trigger input impedance is 1M Ohm. This lets you use passive
probes for general- purpose measurements. The higher impedance
minimizes the loading effect of the oscilloscope on the device under test.
To set the EXT TRIG IN units and probe attenuation:
1 Press the [Mode/Coupling] key in the Trigger section of the front panel.
2 In the Trigger Mode and Coupling Menu, press the External softkey.
3 In the External Trigger Menu, press the Units softkey to select between:
• Volts — for a voltage probe.
• Amps — for a current probe.
Measurement results, channel sensitivity, and the trigger level will
reflect the measurement units you have selected.
4 Press the Probe softkey; then, turn the entry knob to specify the probe
attenuation.
The attenuation factor can be set from 0.1:1 to 1000:1 in a 1-2- 5
sequence.
The probe attenuation factor must be set properly for measurements to
be made correctly.
Maximum voltage at oscilloscope external trigger input
CAT I 300 Vrms, 400 Vpk; transient overvoltage 1.6 kVpk
1 M ohm input: For steady-state sinusoidal waveforms derate at 20 dB/decade above
57 kHz to a minimum of 5 Vpk
With N2863A 10:1 probe: CAT I 600 V (DC + peak AC)
With 10073C or 10074C 10:1 probe: CAT I 500 Vpk