Appendix A
Advanced Filters
159
SR865A DSP Lock-in Amplifier
Step Response Graphs
These graphs illustrate the step response of the different filters at 12 and 24 dB/oct. The
advanced filters always settle in less time than the RC filters. Gaussian filters have
increasing latency with more stages. Linear Phase filters have ≤ 1% overshoot.
1.0
0.8
0.6
0.4
0.2
0.0
Response (V)
7
6
5
4
3
2
1
0
Time (t
c
)
12dB/oct
RC
Gaussian (FIR)
Linear Phase
Time to reach 1% of final value:
RC: 6.6 t
c
Gaussian: 4.0 t
c
Linear Phase: 4.4 t
c
1.0
0.8
0.6
0.4
0.2
0.0
Response (V)
10
8
6
4
2
0
Time (t
c
)
24dB/oct
RC
Gaussian (FIR)
Linear Phase
Time to reach 1% of final value:
RC: 10 t
c
Gaussian: 7.1 t
c
Linear Phase: 5.4 t
c
Gaussian suffers
from latency
Summary of Contents for SR865A
Page 5: ...Safety and Preparation For Use iii SR865A DSP Lock in Amplifier...
Page 6: ...iv Safety and Preparation For Use SR865A DSP Lock in Amplifier...
Page 54: ...36 Getting Started Chapter 1 SR865A DSP Lock in Amplifier...
Page 118: ......
Page 172: ......
Page 186: ...168 The FFT Display Appendix B SR865A DSP Lock in Amplifier...
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