CauerLowPassSC

Cauer low-pass filter with operational amplifiers and switched capacitors

Diagram

Information

This information is part of the Modelica Standard Library maintained by the Modelica Association.

The example CauerLowPassSC is a low-pass-filter of the fifth order. It is realized using an switched-capacitor network with operational amplifiers. The voltage source V is the input voltage (step), and the OP5.out.v is the filter output voltage. The pulse response is calculated.

This model is identical to the CauerLowPassAnalog example, but inverting. To get the same response as that of the CauerLowPassAnalog example, a negative voltage step is used as input.

This model is identical to the CauerLowPassOPV example. But the resistors are realized by switched capacitors (see SwitchedCapacitor). There are two different types of instances, one with a value of R=1 and one with a value of R=-1.

The simulation end time should be 60. Please plot both V.v (which is the inverted input voltage) and OP5.out.v (output voltage). Compare this result with the CauerLowPassAnalog result.

Due to the recharging of the capacitances after switching the performance of simulation is not as good as in the CauerLowPassOPV example.

Parameters (7)

l1

Value: 1.304

Type: Capacitance (F)

Description: Filter coefficient i1

l2

Value: 0.8586

Type: Capacitance (F)

Description: Filter coefficient i2

c1

Value: 1.072

Type: Capacitance (F)

Description: Filter coefficient c1

c2

Value: 1 / (1.704992 ^ 2 * l1)

Type: Capacitance (F)

Description: Filter coefficient c2

c3

Value: 1.682

Type: Capacitance (F)

Description: Filter coefficient c3

c4

Value: 1 / (1.179945 ^ 2 * l2)

Type: Capacitance (F)

Description: Filter coefficient c4

c5

Value: 0.7262

Type: Capacitance (F)

Description: Filter coefficient c5

Components (32)

C1

Type: Capacitor

C2

Type: Capacitor

C3

Type: Capacitor

C4

Type: Capacitor

C5

Type: Capacitor

Op1

Type: IdealOpAmp3Pin

G

Type: Ground

Op2

Type: IdealOpAmp3Pin

Op3

Type: IdealOpAmp3Pin

G1

Type: Ground

C6

Type: Capacitor

Op4

Type: IdealOpAmp3Pin

Op5

Type: IdealOpAmp3Pin

C7

Type: Capacitor

C8

Type: Capacitor

C9

Type: Capacitor

G2

Type: Ground

G3

Type: Ground

G4

Type: Ground

V

Type: StepVoltage

Ground1

Type: Ground

R4

Type: SwitchedCapacitor

R5

Type: SwitchedCapacitor

R8

Type: SwitchedCapacitor

R9

Type: SwitchedCapacitor

R1

Type: SwitchedCapacitor

R2

Type: SwitchedCapacitor

R3

Type: SwitchedCapacitor

Rp1

Type: SwitchedCapacitor

R7

Type: SwitchedCapacitor

R10

Type: SwitchedCapacitor

R11

Type: SwitchedCapacitor