Design of Very High-Frequency Multirate Switched-Capacitor Circuits
presents the theory and the corresponding CMOS implementation of the
novel multirate sampled-data analog interpolation technique which has
its great potential on very high-frequency analog frond-end filtering
due to its inherent dual advantage of reducing the speed of
data-converters and DSP core together with the specification relaxation
of the post continuous-time filtering. This technique completely
eliminates the traditional phenomenon of sampled-and-hold
frequency-shaping at the lower input sampling rate. Also, in order to
tackle physical IC imperfections at very high frequency, the
state-of-the-art circuit design and layout techniques for high-speed
Switched-Capacitor (SC) circuits are comprehensively discussed:
-Optimum circuit architecture tradeoff analysis
-Simple speed and power trade-off analysis of active elements
-High-order filtering response accuracy with respect to capacitor-ratio
mismatches
-Time-interleaved effect with respect to gain and offset mismatch
-Time-interleaved effect with respect to timing-skew and random jitter
with non-uniformly holding
-Stage noise analysis and allocation scheme
-Substrate and supply noise reduction
-Gain-and offset-compensation techniques
-High-bandwidth low-power amplifier design and layout
-Very low timing-skew multiphase generation
Two tailor-made optimum design examples in CMOS are presented. The first
one achieves a 3-stage 8-fold SC interpolating filter with 5.5MHz
bandwidth and 108MHz output sampling rate for a NTSC/PAL CCIR 601
digital video at 3 V. Another is a 15-tap 57MHz SC FIR bandpass
interpolating filter with 4-fold sampling rate increase to 320MHz and
the first-time embedded frequency band up-translation for DDFS system at
2.5V. The corresponding chip prototype achieves so far the highest
operating frequency, highest filter order and highest center frequency
with highest dynamic range under the lowest supply voltage when compared
to the previously reported high-frequency SC filters in CMOS.