Designing a Transconductance-C (Gm-C) low pass filter in 0.35 μm CMOS technology node from TSMC using LTSpice circuit simulator for the given specifications.
BROAD EXPECTATIONS:
Realizing an ideal Gm-C Filters
a) Ideal Filer using RLC circuit which meets the specifications.
b) Ideal Gm-C filter for the specifications using macromodel for the Gm.
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Designing the transconductor in 0.35 μm CMOS technology node from TSMC and validating its use as a Gm-C integrator. The capacitor calculated to be used in the first node of the filter may be used as the integrating capacitor for testing the Gm-C integrator.
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Realize the transistor level Gm-C filter for the given specification.
COMMON SPECIFICATIONS:
- Fourth order Maximally flat response
- Power supply 3.3 V
- Use length of 0.5 μm for all transistors
- Use even number of fingers for the transistors.
TRANSCONDUCTOR SPECIFICATIONS:
- Gm = 1 mS
- Gate overdrive for input transistors = 200 mV
- Input/output common-mode voltage = 1.65 V
FILTER SPECIFICATIONS:
- Attenuation at pass band edge = 2 dB
- Band-edge = 110 MHz