Current Measurements

'Current Measurement' hardware is often used when the current is measured directly by a multimeter connected in ampere-meter configuration.



When clicking on the “Current Measurements” picture, the following menu appears on the right side of the schematic editor:



Instrument

  • Driver: select the appropriate driver corresponding to the instrument (refer to Supported IV Measurement list)
  • Address: set the communication address. Note the icon can be use to open the Instrument Scanner
  • Options: set the specific driver options clicking on icon (refer to Supported Instruments section)
  • VISA Library: set the VISA Library (*.dll) used to communicate with the instrument (see help on this page: Getting Started : "Configure the VISA Library on the control PC")
  • Command Time Out (ms): elapsed time before returning an error message if no response from the instrument
  • Command Delay (ms): delay before sending a command to the instrument

General

  • Measurement Mode: choose the measurement mode (DC or Pulsed)
  • Current Measurement Channel: select the current measurement channel
  • Current Measurement Probe: various current measurements methods can be used. There is a list in the drop-down menu:
    • ‘Automatic detection’ has to be selected when using the AMCAD PIV system
    • ‘Direct’ means that the current is directly measured from the instrument (used with standard DC supplies or voltmeter)
    • ‘Differential’ use a differential voltage probe connected across a serial resistance (RgS in the Resistive Network) to determine the current. Different measurement ranges (Automatic, Low, Medium, High) can be selected depending on the instrument and driver specifications
    • 'Hall’ means that a Hall current probe is used. Different measurement ranges (Automatic, Low, Medium, High) can be selected depending on the probe and driver specifications

Correction

  • Measurement Averaging: set the averaging.
  • Correction Factor: set a correction factor, which multiplies the value of the measurement (useful when IV Pulsed measurement is impossible)
  • Correction Offset: set a correction offset, which adds (or subtracts) a constant value
  • Invert Polarity: check this box to invert the polarity. The inverse polarity is used when the positive and ground terminals of a single quadrant power supply is used to feed and measure a negative bias voltage. Even though the instrument will return a positive values, IQSTAR will automatically return the inverse of this value

Trigger (available only in Pulsed mode)

Select the Internal or External Positive/Negative Edge Trigger. Basically, the external positive edge trigger signal comes from the VNA or the RF Source.

Measurement Windows (Quiescent) (available only in Pulsed mode)

  • Measurement Delay in Quiescent Area: set the delay of the quiescent measurement window
  • Measurement Width in Quiescent Area: set the width of the quiescent measurement window
Note: These timings can be re-adjusted in the 'Chronograms' tab.

Measurement Windows (Pulse) (available only in Pulsed mode)

  • Measurement Delay in Pulse Area: set the delay of the pulse measurement window
  • Measurement Width in Pulse Area: set the width of the pulse measurement window
Note: These timings can be re-adjusted in the 'Chronograms' tab.

Trace (available only in Pulsed mode)

  • Trace Start: set the trace start.
  • Trace Stop: set the trace stop.
  • Trace Sampling: set the trace sampling.
Note: These settings are used to record a time domain IV screenshot. This feature is only available using an oscilloscope.