Oscilloscope Tab

Probe Setup, Headroom, and Timescale

• Use Automatic Headroom Factor: Applies a factor to the y-axis of the Oscilloscope Capture display. When checked, the software detects clipping in the waveforms and automatically adjusts the vertical scale.

Default Headroom Factor for all oscilloscope channels is 1.6. Alternately, you can specify the headroom factor for each channel separately. For many GaN devices, the Headroom factor should be set to 2 or as high as 3.6 for the Channel 2, Output Current I_D/I_C.

Refer to Oscilloscope Probe Setup for an explanation of the various probe locations. Color bars correspond to oscilloscope channel colors.

• Gate Voltage V_GS,L/V_GE,L: Specify oscilloscope channel (default: Oscilloscope Channel 1) for the Low-Side Control Signal measurement.

• Output Voltage V_DS,L/V_CE,L: Specify oscilloscope channel (default: Oscilloscope Channel 3) for the Low-Side Output Voltage measurement.

• Output Current I_D,L/I_C,L: Specify oscilloscope channel (default: Oscilloscope Channel 2) for Output Current measurement. This is the current measured across the Coaxial Shunt Resistor with the PD1000-60002 Oscilloscope Probe.

• Gate Current I_G,L: Specify oscilloscope channel (default: Oscilloscope Channel 4) for Gate current measurement IG. IG is the current measured across the Gate Resistor.

• Output Voltage V_DS,H/V_CE,H: Specify oscilloscope channel (default: Oscilloscope Channel 5) for the High-Side Output Voltage measurement.

• Gate Voltage V_GS,H/V_GE/H: (default: Memory Channel 6). This is the Gate Voltage measured on the High-Side Gate Drive Module with an N2873A 10:1 Oscilloscope Probe.

  • Use Isolated Probe Unit for V_GS,H/V_GE,H: Check this box only if you need to measure High-Side output voltage. Configure the Isolated Probe Unit:

  • Measure Channel: Default channel on the Isolated Probe Unit is Channel A. Other channels are reserved for future use.

  • Probe Attenuation Ratio: Specify the attenuation ration of the oscilloscope probe. The standard Keysight N2873A Passive Probe is 10:1 (default).

  • Trigger Channel: Select External Trigger. The other options are for the Isolated Probe Unit channel and are reserved for future use only.

• Output Current I_D,H/I_C,H: (default: Oscilloscope Channel 7). Note that Keysight does not provide a High-Side shunt resistor for the PD1550-66560 or PD1550-66560 62 mm Interface Modules. However, for your custom Interface Modules you may design a place to install a small Rogowski coil current probe.

• Timescale Factor: Applies a factor to the x-axis of the Oscilloscope Capture display. Default is 1.0

Oscilloscope Options

• Use High Resolution Acquisition: Turns on (box is checked) or off (box is unchecked, default) the Infiniium oscilloscope’s High Resolution Acquisition Mode. (Normal Acquisition is the default, box not checked).

• High Resolution Acquire Mode: If the Use high resolution acquisition is turned on, sets the mode for the oscilloscope’s high resolution data acquisition – BITS10 (default), BITS11, BITS12, BITF13, and BITF14. This determines the minimum number of vertical resolution bits which affects the sampling rate. Do not use BITF13 or BITF14; they are not applicable to the bandwidth of the oscilloscope.

• Bandwidth Limit Mode: Sets the bandwidth limit mode – Hw200MHz (default), Hw20MHz, Custom, or Off – for oscilloscope’s input channel’s low-pass filter.

• Custom Bandwidth Limit (MHz): Minimum value is 3 MHz; maximum value is (sample rate)/2. Field is editable only when Bandwidth limit mode is set to Custom.