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Document #7650-0038 Rev A1. © Copyright 2019 Directed Energy, Inc. All rights reserved.
4.2 Load Simulation
The PVX-4140 B was tested with a 50 pF capacitive load connected to the output via
6 feet of RG-59 coaxial cable.
4.3 Gate Input
A logic level of +5 V ±1 V into 50
Ω
with a rise time of <20 ns is required to gate the
PVX-4140 B. Departure from these values can result in a loss of performance. These
requirements are met by any high-quality, logic-level pulse generator. The source
should be configured to +5 V ±1 V into 50
Ω
before the cable is attached to the PVX-
4140 B Gate input. The amplitude of the gate pulse should be set using a 50
Ω
load
(e.g., a 50
Ω
scope input) before connecting it to the PVX-4140 B. If the gate pulse is
greater than +5 V into 50
Ω
, pulse stretching can occur.
4.4 High Voltage Inputs
The absolute maximum rating for the high voltage inputs is ±3500 V. In addition, the
+HV Input must never be greater than +3500 V above the -HV Input. Precautions
should be taken to ensure that these maximum voltages are not exceeded.
4.5 Output Pulse Considerations
The PVX-4140 B can generate single-ended output pulses from ground to +3500 V or
from ground to -3500 V. It can also generate pulses originating from a voltage offset
from ground. This offset can be from -3500 V to +3500 V, but the +HV Input should
always be equal to or greater than the -HV Input and never greater than +3500 V
above the -HV Input.
If the instrument is operated with a single power supply for unipolar pulses, the unused
high voltage input must be grounded.
When the Gate input is high, the +HV Input is switched to the output. When the Gate
input is low, the -HV Input is switched to the output. The PVX-4140 B can generate a
negative-going pulse by logically inverting the Gate input so that the Gate input is high
until a pulse is generated. When the Gate input goes low, the -HV Input is switched to
the output, thereby generating a negative going pulse (see the figure below).
