Operation; Connecting To The Test Instrument; Connecting To The Test Circuit - Teledyne Lecroy HVD3000 Series Operator's Manual

Operation

Connecting to the Test Instrument

The HVD3000 Series probes have been designed for use with Teledyne LeCroy oscilloscopes
equipped with the ProBus interface. When you attach the probe output connector to the
oscilloscope's input connector, the instrument will:
Recognize the probe
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Set the oscilloscope input termination to 1 MΩ
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Activate the probe control functions in the oscilloscope user interface.
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NOTE: For accurate measurements, connect the probe to the oscilloscope and allow to warm
up for at least 20 minutes. Perform Auto Zero prior to connecting the probe to the DUT.

Connecting to the Test Circuit

Two inputs are available at the probe tip to connect the probe to a circuit under test. For
accurate measurements, both the + and – inputs must be connected to the test circuit.
Positive voltages applied to the + input (red) relative to the – input (black) will deflect the
oscilloscope trace toward the top of the screen.
To maintain the probe's high performance capability, exercise care when connecting the probe.
Increasing the parasitic capacitance or inductance in the input paths may introduce a "ring" or
slow the rise time of fast signals. Input leads that form a large loop area will pick up any
radiated electromagnetic field that passes through the loop and may induce noise into the
probe inputs. Because this signal will appear as a differential mode signal, the probe's common
mode rejection will not remove it. This effect can be reduced by twisting the input leads
together to minimize the loop area.
WARNING. To avoid electric shock or fire, maintain the input leads in good condition.
The leads have a jacket wear indicator that shows through when the jacket is
excessively worn. If the white "WEAR" indicator on the input leads is visible, cease use
and contact Teledyne LeCroy service for repair or replacement.
High common mode rejection requires precise matching of the relative gain or attenuation in
the + and – input signal paths. Mismatches in additional parasitic capacitance, inductance,
delay, and a source impedance difference between the + and – signals will lower the CMRR.
Therefore, it is desirable to use the same length and type of wire and connectors for both input
connections. When possible, try to connect the inputs to points in the circuit with
approximately the same source impedance.
The probes may be stacked on one top of another during usage to conserve space. Since the
probe body generates heat, and the stacking reduces cooling, it is recommended that ambient
temperatures not exceed 30 degrees C while stacked probes are in operation. The exceptional
CMRR performance should prevent interference between probes when they are stacked, but
Operation
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