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- Bode Plot shows enough suppression at noise signal frequency.
- Waveform shows clear HIGH and LOW signals, a good example is shown below. (Green: input noise signal, blue: output filtered signal)
- Successfully demodulated messages with a reasonable PSR at 1000 packet counts.
Characterise your design (LTSpice and Breadboard Circuit)
To characterise your design, you could make use of the following:
- Analyse the frequency response (Bode Plot):
- LTSpice: Small Signal AC Analysis (sweep)
- Waveforms: Network
- Analyse the frequency components and power level:
- LTSpice: FFT
- Waveforms: Spectrum
- Observe the signal waveform:
- LTSpice: Simulate with recorded .sig file and probe the in/output
- Waveforms: Scope
- Eye Diagram:
- Waveforms: Scope
Common Debug Flow (when no PSR value observed)
| Warning |
|---|
Possible cause 1: Signal Recording Error |
| Tip |
|---|
Solution: Double check the recording setting and re: Setting → Device Manager → Option 2 (2x16k) Config → Samples: 32768, Rate: 4MHz, Base: 7.5ms Zero Offset after recording |
Scenario 1: When Bode Plot cutoff at designed frequency but no message can be demodulated.
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