Objectives
Design Specs and Transfer Function
Circuit Simulations & Results Interesting Facts References
Design Specs & Transfer Function 2nd Order Salleen-
Key HPF 2nd Order Salleen-
Key LPF Inverting
Amplifier
Circuit Simulations & Results
Spice & Lab Output Gain Analysis
0.000
0.500
1.000
1.500
2.000
2.500
1 10 100 1000 10000 100000 1000000 10000000
Frequency (Hz)
Gai
n LGain
SGain Measured Gain and Spice Gain
Spice & Lab Output dB Gain
-100.000
-80.000
-60.000
-40.000
-20.000
0.000
20.000
1 10 100 1000 10000 100000 1000000 10000000
Frequency (Hz)
DB
Ga
inLdB Gain
SdB GainMeasured and Spice dB
Gain
ContinueSpice & Lab Output Phase
-600.000
-500.000
-400.000
-300.000
-200.000
-100.000
0.000
100.000
1 10 100 1000 10000 100000 1000000 10000000
Frequency (Hz)
Ph
ase
(deg
rees
)
LPhase (Deg)
SPhase (Deg)
Measured and Spice Phase Angle
Continue
Time
0s 20us 40us 60us 80us 100us 120us 140us 160us 180us 200usV(v_vout) V(v_vin)
-15V
-10V
-5V
0V
5V
Transient Response of the Interesting Filter
Capacitor Change Simulations
Frequency
10Hz 100Hz 1.0KHz 10KHz 100KHz 1.0MHz 10MHzV(v_vin) V(Saleen_Key_High_Pass) V(Saleen_Key_Low_Pass) V(v_vout)
0V
0.5V
1.0V
1.5V
2.0V
V(v_vin) V(Saleen_Key_High_Pass) V(Saleen_Key_Low_Pass) V(v_vout)
Time
0s 20us 40us 60us 80us 100us 120us 140us 160us 180us 200usV(v_vout) V(v_vin)
-15V
-10V
-5V
0V
5V
Frequency Response
Transient Response
Why is it an Interesting Filter?
Lower Stop Frequency at 16Hz 20db/decade
Upper Stop Frequency at 320Hz 20db/decade
Roll-Off at 310kHz 75db/decade