Tri-State pulse system

In the Tri-State pulse system, three independent voltage levels can be impressed on the GATE side as well as on the DRAIN side: DC voltage, pre-pulse and main pulse. For this reason, this system is called a “Tri-State” pulse system. As with single-pulse systems, the GATE pulse can be set synchronously with the DRAIN pulse. For the Tri-State pulse system, the measuring options of the single-pulse system are available for the main pulse, which are extended with measurements on the pre-pulse.

Memorised voltages of the Tri-State pulse system

The following parameters are configurable via SW:

DC voltage at GATE and DRAIN.
Pulse voltage at GATE and DRAIN for pre-pulse and main pulse.
Timing of fully synchronised pre-pulse and main pulse at GATE and DRAIN.
Selection times for measuring current and voltage.
Presetting of a maximum current at the DRAIN. If exceeded, the voltage is limited to protect the test module.
Pulse repetition rate in the possible value range.

DC calibration with calibration resistors.

Module type	PHG20 for GATE pre-pulse or main pulse	PHG100 for GATE pre-pulse or main pulse	PHD220-2 for DRAIN pre-pulse or main pulse	PHD220-10 for DRAIN pre-pulse or main pulse	PHD220-30 for DRAIN pre-pulse or main pulse
Maximum voltage pre-pulse	+/-20 V	+/-100 V	220 V	220 V	220 V
Maximum current pre-pulse	100 mA	100 mA	2 A	2 A	2 A
Maximum DC current pre-pulse	100 mA	100 mA	-	-	-
Maximum pulse power pre-pulse	2 watt	2 watt	40 watt	40 watt	40 watt
Minimum pulse width pre-pulse	200 ns	200 ns	200 ns	200 ns	200 ns
Maximum voltage main pulse	+/-20 V	+/-100 V	220 V	220 V	220 V
Maximum current main pulse	100 mA	100 mA	2 A	10 A	30 A
Maximum DC current main pulse	100 mA	100 mA	0.85 A	1.7 A	5 A
Maximum pulse power main pulse	2 watt	2 watt	40 watt	200 watt	1000 watt
Minimum pulse width main pulse	200 ns	200 ns	200 ns	200 ns	1000 ns

Table 2: Characteristics of the PIV modules for Tri-State pulse systems

The basic modules used to form the larger Tri-State modules are summarised in Table 2. The GATE side, consisting of two basic modules, can be formed with PHG20 or PHG100 modules. For the DRAIN side, the modules PHD220-2, PHD220-10 or PHD220-30 are available.

As with the single-pulse system, the test module is contacted with only one coaxial supply line per input and output. An extended PIV controller must be used to achieve the necessary functionality.

Here an example of a measurement in the time range is shown. The following measurement curves are shown:

Measured GATE and DRAIN voltage for the measurement with pre-pulse
Measured DRAIN current for a voltage impression with pre-pulse
Measured DRAIN current for a voltage impression without pre-pulse (the corresponding voltage curve is not shown)

Tri-State pulse measurement in the time range

With the integrated oscilloscope, current and voltage can be recorded over the time range of the pulse. The superimposed coloured areas are used to select the measuring point for recording current-voltage characteristics where only one set of measured values is stored per operating point.

Here is an example of the performance of a power module on which the current-voltage characteristic curve in the main pulse with pre-pulse was measured on one occasion and without pre-pulse on the other. This example shows how significantly the current in the main pulse operating point can depend on the pre-pulse.