User`s guide

Triggering 4
InfiniiVision Oscilloscopes User’s Guide 93
Input Impedance The 2-channel oscilloscopes have selectable external trigger input
impedance. The impedance can be set to either 1M Ohm or 50 Ohm by pressing the
Imped softkey.
•50Ohm — matches 50-ohm cables commonly used in making high frequency
measurements. This impedance matching gives you the most accurate measurements
since reflections are minimized along the signal path.
•1MOhm — is for use with many passive probes and for general-purpose
measurements. The higher impedance minimizes the loading effect of the
oscilloscope on the device under test.
Probe Units Press the Units softkey to select the proper measurement unit for the
connected probe. Select Volts for a voltage probe and select Amps for a current probe.
Measurement results, channel sensitivity, and trigger level will reflect the measurement
units you have selected.
CAUTION
Maximum voltage at 2-channel oscilloscope external trigger input:
CAT I 300 Vrms, 400 Vpk; transient overvoltage 1.6 kVpk
CAT II 100 Vrms, 400 Vpk
50 input: 5 Vrms
Input protection is enabled in 50 mode and the 50 load will disconnect if greater
than 5 Vrms is detected. However the inputs could still be damaged, depending on
the time constant of the signal. The 50 input protection only functions when the
oscilloscope is powered on.
1 M ohm input, 100 MHz models:
For steady-state sinusoidal waveforms derate at 20 dB/decade above 200 kHz to a
minimum of 10 Vpk
1 M ohm input, 350 MHz, 500 MHz, 1 GHz models:
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, CAT II 300 V (DC + peak AC)
With 10073C or 10074C 10:1 probe: CAT I 500 Vpk, CAT II 400 Vpk