Slew Rate and Transient Response (Gain Bandwidth)

Because the PXIe-4051 allows system bandwidth or speed programming, the achievable maximum slew rate is limited by the setup system bandwidth. You can make and optimize the system bandwidth using Transient Response adjustments through the SourceAdapt settings.

Due to physical limitations, you cannot slew faster than what the system bandwidth, including the PXIe-4051, wiring, and DUT, allows. Through the PXIe-4051, you can optimize your system bandwidth with a custom transient response and compensation. This allows you to achieve the maximum slew rate possible with your specific setup.

The slew rate control functionality allows you to define a desired slew rate for setpoint parameter in Constant Current mode. You can control the maximum slew rate (in A/us) between setpoints for both single point mode and sequence mode.

Adjusting the maximum slew rate will not change the user-programmed step size but will provide a more deterministic control of the signal behavior between setpoints. The timing of receiving the Source Complete event and the Measure Complete event will not be impacted by the slew rate configuration.

The actual slew rate achieved between setpoint steps will not exceed the specified slew rate. The actual rate can become slower than what you have set if one of the following situations takes place:
  • The transient response parameter takes precedence.
  • The compliance parameter takes precedence.
  • The maximum slew rates of the power stage are reached.
Slew rate control is implemented digitally through a linear interpolation filter between the user’s sequence setpoints being applied and the setpoint in the digital loop.
Maximum realizable slew rates are limited by the programmed Gain Bandwidth (and compensations) in the transient response settings and by the limitations of the setup and system. However, you can use a programmable slew rate to obtain:
  • Slower slew rates.
  • Independent rising and falling slew rates.
  • Unique slew rates for each step in a sequence

If the slew rates are programmed to be slower than the sequence step time, then you will not be able to achieve the steady state of programmed setpoint within the step timing that you desire.

Note Programmable Slew rates are available for Constant Current Mode only.