This dissertation presents design and implementation of continuous time analog
filters for two specific applications: wideband analog systems such as disk drive channel
and low-power wireless applications. Specific focus has been techniques that reduce the
power requirements of the overall system either through improvement in architecture or
efficiency of the analog building blocks.
The first problem that this dissertation addresses is the implementation of
wideband filters with high equalization gain. An efficient architecture that realizes
equalization zeros by combining available transfer functions associated with a
biquadratic cell is proposed. A 330MHz, 5th order Gm-C lowpass Butterworth filter with
24dB boost is designed using the proposed architecture. The prototype fabricated in
standard 0.35um CMOS process shows -41dB of IM3 for 250mV peak to peak swing
with 8.6mW/pole of power dissipation. Also, an LC prototype implemented using
similar architecture is discussed in brief. It is shown that, for practical range of frequency and SNR, LC based design is more power efficient than a Gm-C one, though
at the cost of much larger area.
Secondly, a complementary current mirror based building block is proposed,
which pushes the limits imposed by conventional transconductors on the powerefficiency
of Gm-C filters. Signal processing through complementary devices provides
good linearity and Gm/Id efficiency and is shown to improve power efficiency by nearly
7 times. A current-mode 4th order Butterworth filter is designed, in 0.13um UMC
technology, using the proposed building. It provides 54.2dB IM3 and 55dB SNR in
1.3GHz bandwidth while consuming as low as 24mW of power. All CMOS filter
realization occupies a relatively small area and is well suited for integration in deep
submicron technologies.
Thirdly, a 20MHz, 68dB dynamic range active RC filter is presented. This filter
is designed for a ten bit continuous time sigma delta ADC architecture developed
specifically for fine-line CMOS technologies. Inverter based amplification and a
common mode feedback for such amplifiers are discussed. The filter consumes 5mW of
power and occupies an area of 0.07 mm2.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/ETD-TAMU-2009-08-874 |
| Date | 2009 August 1900 |
| Creators | Gambhir, Manisha |
| Contributors | Sanchez-Sinencio, Edgar, Silva-Martinez, Jose |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | Book, Thesis, Electronic Dissertation, text |
| Format | application/pdf |
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