I am the inventor (or co-inventor) of the inventions described in the following patents and patent publications:
US 5,982,317 : Oversampled Digital-to-Analog Converter Based on Nonlinear Separation and Linear Recombination
This patent teaches how to implement a mismatch-shaping encoder for use with
an array of scaled (say, binary weighted) analog sources, such as to implement a
high-resolution digital-analog converter. The invention is useful, in part, to
implement the data converters needed for audio CD and DVD playback units.
US 6,215,348 : Bootstrapped Low-Voltage Switch
This patent teaches how to implement CMOS switches that has a nearly
signal-independent impedance. They can be used to implement the sampling
switch in high-speed data converters. They can operate from a supply
voltage that is only marginally higher than the technology's threshold voltage,
and hence these switches are also use for the implementation of general-purpose
low-voltage switched-capacitor circuits.
US 6,271,782 : Delta-Sigma A/D Converter
This patent teaches how to implement a specific hybrid of delta-sigma A/D
converters. It also teaches a system topology that is now widely used to
stabilize delta-sigma data converters based on a continuous-time loop filter.
US 6,348,884 : Idle-tone-Free Mismatch-Shaping
Encoders
One may show that first-order mismatch-shaping generally is sufficient to
suppress the errors introduced by element mismatch in data converters
implemented in a typical CMOS technology (the matching is pretty good, and kT/C
noise will generally dominate the mismatch-induced noise even at relative low
oversampling ratios). Idle tones, however, are a real problem in most
first-order mismatch-shaping encoders. Second-order encoder are generally
much better in terms of idle tones, but their complexity is prohibitive.
This patent teaches how to eliminate idle tones in even the simplest first-order
mismatch-shaping encoders, which effectively voids the need for higher-order
encoders.
US 6,473,011 : Serial D/A Converter Compensating
for Capacitor Mismatch Errors
This patent teaches how a high-performance D/A converter can be implemented using only two capacitors and a small digital state machine. The technique is remarkable in its simplicity, but it does not measure up to other techniques in terms of performance versus power consumption.
US 6,556,158 : Residue-Compensating A/D Converter
This patent teaches how the best properties of pipeline ADCs (high
throughput, low circuit complexity) can be combined with the best properties of
delta-sigma ADCs (low sensitivity to mismatch and other circuit imperfections).
The result is a high-throughput (>10MS/S) and high-resolution (14-16 bits) data
converter with relatively low circuit complexity and power consumption.
US 6,573,790 : Wide-Bandwidth Operational
Amplifier
This patent teaches how the principles that have been applied very successfully to delta-sigma data converters can be re-used with significant advantage for the implementation of low-distortion amplifiers. A main limitation for this invention is that it requires that the amplifier's load is well controlled.
US 6,952,174: Serial Data Interface
This patent teaches how the data stream from a two-bit delta-sigma ADC can be encoded by a small digital state machine such that it can be communicated over a serial interface. The encoding is performed such that relatively few transitions occur on the interface, which results in a net power savings, while exhibiting a good robustness to bit errors.