TIDUFE3 July 2025
- 1
- Description
- Resources
- Features
- Applications
- 6
- 1System Description
- 2System Overview
- 3System Design Theory
- 4Hardware, Software, Testing Requirements, and Test Results
- 5Design and Documentation Support
- 6About the Author
4.3.3 Step Response
To test the step response of the circuit, the circuit is again connected to a 24V power supply. Current measurement is done with a current clamp with multiple turns of the loop wire in the clamp to increase the sensitivity.
The step is generated by sending the corresponding DAC values from a PC to the AFE88x. In this test a step from zero to maximum and back as well as midpoint current is performed. This shows the slew rates of the analog circuit and is also testing the stability.
Figure 4-27 shows the complete setup.
Figure 4-27 Test Setup for Step Response MeasurementsThe following figures show the step responses of the current.
Figure 4-28 AFE881: 3.3V, Rise Time 0 to 65535
Figure 4-30 AFE881: 3.3V, Rise Time 0 to 32768
Figure 4-32 AFE881: 1.8V, Rise Time 0
to 65535
Figure 4-34 AFE881: 1.8V, Rise Time 0 to 32768
Figure 4-36 AFE882: 3.3V, Rise Time 0 to 65535
Figure 4-38 AFE882: 3.3V, Rise Time 0 to 32768
Figure 4-29 AFE881: 3.3V, Fall Time 65535 to 0
Figure 4-31 AFE881: 3.3V, Fall Time 32768 to 0
Figure 4-33 AFE881: 1.8V, Fall Time 65535 to 0
Figure 4-35 AFE881: 1.8V, Fall Time 32768 to 0
Figure 4-37 AFE882: 3.3V, Fall Time 65535 to 0
Figure 4-39 AFE882: 3.3V, Fall Time 32768 to 0