Analog Filters

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Lecture 6 Higher Order Filters Using Inductor
Emulation
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Inductor Emulation Using Two-port Network
GIC (General Impedance Converter)
GII (General Impedance Inverter)
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Gyrator
Positive Impedance Inverter
Floating inductor
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Gyrator Example
Gyration resistance1/g11/g2R
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Riordan Gyrator
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Example
For Gyration resistance1kO
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Antoniou GIC
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Antoniou GIC
Inductance emulation is optimum in case of no
floating inductors i.e., LC high-pass filters
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Example
3rd Order LPF
6th Order BPF
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Brutons transformation
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FDNR
Brutons inductor simulation based on FDNR Most
suitable for LC LPF with minimum cap realization
12
Filter Performance Design Trade-offs

• Transfer function
• (?0 , Q or BW, Gain, out-of-band attenuation,
  etc.)
• Sensitivity (component variations, parasitics)
• Dynamic range (DR)
• Maximum input signal (linearity)
• Minimum input signal (noise)
• Power dissipation Area

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Maximum signal (supply limited)
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Voltage swing scaling
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Power dissipation
For nth order
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Minimum signal (noise limited)

• Thermal noise of a resistor

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• Example low-pass filter

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Simple Example
Large power, large area
Large C, Small R
Large noise, parasitic sensitive
Large R, Small C