Inventor
Don R. Sauer
Address: San Jose, CA


12/945,704
A WORKING RECTIFIER LESS AC<=>DC BREADBOARD
filed 11-12-2010

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12/839,890
ENERGY HARVESTING RESISTOR
filed 09-10-2010

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7,839,317 B1
A FOLDING COMPARATOR COMPATIBLE WITH LEVEL-CROSSING
SAMPLING



US7839317.jpg



7,622,991 B2
TRANSCONDUCTANCE SIGNAL CAPACITY FORMAT
Applying signal as a percentage format rather than as a voltage or current format
allows a multiple of transconductance amplifiers to be maintained at their optimum
performance levels in terms of gain, frequency response, distortion, dc offset,
intended impedance, temperature drift, and signal to noise ratio.


OTAformat.jpg

This patent provides a way to use OTAs at their optimum signal
performance levels.



7,463,094 B2
LINEARIZED CLASS AB BIASED DIFFERENTIAL INPUT STAGE
A linearized bipolar differential input stage that contains two high gain current
mirrors coupled in series with the input voltage signal through the input transistors to
5 allow the output differential current to greatly exceed the DC output current in a Class
AB fashion.

AB_input.jpg

Provides improvements in distortion, noise, and offset.

This patent was completely done online.



7,339,755
Ring device with optical focusing mechanism
A ring device is adapted for wearing on at least one finger of a user.
The ring device includes a wearable main body portion and an optical member
that is moveably affixed thereto. The optical member can be positioned in..

7,339,755.jpg

Work in progress. Still testing prototypes with some improvements.
Finding a need for wearing and using a
prototype like this everyday.




6,677,808
CMOS adjustable bandgap reference with low power
and low voltage performance

A voltage reference circuit is arranged in a CMOS process based technology
to provide a configurable voltage reference.
The voltage reference includes bipolar
transistors that are implemented as parasitic devices in the CMOS process.
Two of the bipolar transistors are configured to generate a...

6677808.jpg
This really is the work of S.Chen Sean. But my name was included on it
for some reason.



6,614,293
Method and apparatus for improving current matching
in an electronic circuit

A Sauer diode circuit is arranged to introduce a signal into a circuit
to compensate for mismatch effects to various parameters in a current mirror circuit.
Current matching between transistors is improved by providing matched errors
such as forward current gain (Beta), early voltage,...
6614293.jpg
Build the ultimate low voltage precision bandgap voltage reference by
balancing out all errors due to things like beta and early voltage.



6,608,526
CMOS assisted output stage

An output stage for an operational amplifier
includes a dynamically activated CMOS drive circuit
that is arranged to improve the drive characteristics of the
operational amplifier. The output stage includes bipolar transistors
that are arranged to clamp the signal swing at an intermediary node in...
6608626.jpg
Why not shunt the collectors of some already existing output stage
biasing transistors into CMOS mirrors such that when the Bipolar output
transistors reach their limit in current, the CMOS output transistors
kick in and finish the job?



6,518,847
Apparatus and method for a thermal feedback
oscillator

A method and apparatus is directed to generating an oscillation frequency
utilizing the thermal heat transfer properties of semiconductor material
as a feedback loop in an oscillator.
The oscillator includes a comparator that compares two input signals
and enables one of two heater circuits. Each...

6518847.jpg
Exploit the natural thermal time constant of silicon to build
a oscillator or time reference.




6,456,123
Method and apparatus for transferring
a differential voltage to a ground..
.
A translation circuit for transferring a differential voltage
to a ground referenced voltage includes a differential input circuit,
a sample/hold (S/H) circuit, and a compensation circuit.
The S/H circuit includes a S/H capacitor, a series capacitor and a switch.
The S/H and series capacitors are...

6456123.jpg
Provides an optional differential input feature to a single input
Analog to Digital Converter.


6,433,637
Single cell rail-to-rail input/output
operational amplifier

A method and apparatus is directed to a rail-to-rail MOS amplifier
that operates with a very low power supply.
An input stage amplifier operates over rail-to-rail common-mode voltages.
The input stage amplifier includes two differential input stages
that steer current to loads in a class AB...

6433637.jpg6433637out.jpg

A CMOS Rail to Rail input output architecture which works down
to 900mV over temperature.


6,392,465
Sub-threshold CMOS integrator

An integrator circuit having a relatively large RC time constant
includes a resistive element implemented with a field effect transistor
operated in a sub-threshold mode.
The size of the field effect transistor is selected,
in addition to the sub-threshold gate voltage, to achieve a desired...
6392465.jpg
Build sub Hertz Low Pass Filters in Pure CMOS using
internal capacitors.

6,380,723
Method and system for generating a low voltage reference

A single cell voltage reference operates under low power supply requirements
to provide a configurable voltage reference.
The single cell voltage reference includes a diode device
that is biased as a voltage source.
Two series connected resistive devices are connected in parallel with the diode...

6380723.jpg
An architecture for building BandGap References well below 1.2Volts.


6,310,467
LDO regulator with thermal shutdown system and method

A method and apparatus is directed to a thermal shut down
for a low drop out (LDO) regulator including a MOS transistor.
An error amplifier controls the gate of the MOS transistor
by comparing the regulator output voltage to a reference voltage
that is generated by a reference circuit. To enhance...

6310467.jpg
If a Low Drop Out Regulator derives its supply voltage from the
regulated output voltage, this can provide some supply rejection advantages.
There are however some new disadvantages. One problem is how to do thermal
shut down. The architecture in this invention addresses these issues.



6,208,215
VCO and filter controlled by common integrated
thermal frequency reference

A VCO and filter each include a variable transconductance amplifier
as a resistive element.
The same control bias current is supplied to the variable transconductance amplifier
of both the oscillator and filter.
This control bias current may be externally supplied, or may be generated on-chip...

6208215.jpg
If there exist an on chip timing reference, it is possible to
use this timing to
calibrate their frequency response of on
chip filters. This frequency response can be derived from the
natural thermal time constant of silicon.



6,201,377
Match-insensitive low-current bias circuit

A match-insensitive low current bias circuit uses a transistor arrangement
which takes advantage of the transistors' collector current degeneration,
current gain through emitter sizing, and voltage gain
to minimize any errors caused by stage mismatches created during production.
The bias circuit...
6201377.jpg
Bipolar transistors in a BiCMOS process can easily operate well below
1nA. This makes it possible to built subHz Low Pass filters. There
is some sensitivity to component miss match which this architecture
addresses.



6,147,552
Chopper-stabilized operational amplifier
including integrated circuit with...

An improved chopper stabilized operational amplifier is disclosed,
along with an improved method of timing the switchings
of chopper switches in such an amplifier.
The disclosure includes an integrated circuit and method
for generating a true random voltage signal having a truly random RMS...
6147552.jpg

Randomizing the frequency of a chopper amplifier so as to avoid
aliasing is not new. But if a BiCMOS process allows subHz Low
Pass filters to be put completely on chip, then it is possible
to randomize the frequency with real randomness by gaining up shot
noise in a way that constant DC current flows in the supply current
at all time.




6,121,848
Integrated accurate thermal frequency reference

A thermal RC network is fabricated in silicon
as a lateral array of forward-biased PN junctions,
which may take the form of the base-emitter junctions of bipolar transistors.
Application of a clock signal from a voltage controlled oscillator
to the silicon produces a heat pulse which propagates...


6121848.jpg
This is one architecture to exploiting the natural thermal time
constant of silicon in order to build a internal on chip frequency
reference.



6,064,257
Chopper-stabilized operational amplifier

A chopper stabilized operational amplifier
implemented on a single integrated circuit chip is disclosed.
The disclosure includes a symmetrical random signal generator circuit
that produces a true random voltage signal upon application of a DC bias current.
The true random voltage signal is...

6064257.jpg
Randomizing the frequency of a chopper amplifier so as to avoid
aliasing is not new. But if a BiCMOS process allows subHz Low
Pass filters to be put completely on chip, then it is possible
to randomize the frequency with real randomness by gaining up shot
noise in a way that constant DC current flows in the supply current
at all time.



6,002,245
Dual regeneration bandgap reference voltage generator

A dual regeneration bandgap voltage generator circuit
includes both CMOS and bipolar regeneration bandgap voltage generator circuits.
Each of the regeneration bandgap voltage generator circuits
is formed by cross-coupling current mirror circuits of opposite conductivity types.
Upon initial application of power, the CMOS circuit becomes active first...
6002245.jpg
In a BiCMOS process, CMOS devices will draw a small current at
zero volts. They can be connected in a loop which will start up a
Bipolar band gap such that the Bipolar bandgap can as a result
turn off the CMOS loop.




5,963,085
Input to output stage interface with virtual
ground circuitry for rail to rail comparator

An interface stage for interfacing between input and output stages of a rail to rail comparator.
The interface stage combines and amplifies four input stage output currents from the input stage,
including by common base feeding them to a symmetrical set of virtual grounds,
to generate a differential output signal for driving the output stage.
5963085.jpg
The drain nodes to a CMOS input transistors of a comparator can be fed to
a virtual ground which can dominate over stray capacitance to speed up
signal response.



5,959,498
Chopper-stabilized operational amplifier
including low-noise chopper switch

To minimize noise generation a chopper switch for a chopper stabilized operational amplifier
includes a balanced bridge circuit with two pairs
of high-side and lowside transistors connected in parallel.
The transistors are not turned completely off
but operate in the manner of variable resistors...
5959498.jpg
A "chopper" amplifier does not have to chop the input signal using switches.
A more of a "modulation" method can be used where each input is connected
between two MOS devices that are both always on but which alternate in terms
of having greater of lesser impedance. By always keeping all the MOS devices
on, it is easier to balance out the effective switching current spikes that
appear is input noise current to the chopper amplifier when ever a MOS device
is switch on and then off. The idea was to have extremely low input noise
current.




5,926,066
Chopper-stabilized operational amplifier including
integrated circuit with...

An improved chopper stabilized operational amplifier is disclosed,
along with an improved method of timing the switchings
of chopper switches in such an amplifier.
The disclosure includes an integrated circuit and method
for generating a true random voltage signal having a truly random RMS...
5926066.jpg
Randomizing the frequency of a chopper amplifier so as to avoid
aliasing is not new. But if a BiCMOS process allows subHz Low
Pass filters to be put completely on chip, then it is possible
to randomize the frequency with real randomness by gaining up shot
noise in a way that constant DC current flows in the supply current
at all time.




5,793,242
Floating capacitor differential integrator

An integrator circuit is disclosed which overcomes problems in the art described above.
In accordance with the present invention, an integrator circuit
includes a differential input transconductance stage
which converts an input differential signal to a differential current
at first and second internal nodes...
5793242.jpg
The BiCMOS process allows the design of sub Hz Low Pass Filters
completely on chip because bipolar transistors can work
well below nano Amp levels and CMOS transistors have the
input impedance of glass. This type of Low pass filter
makes it possible to gain signal higher that 80dB completely
inside a chip. This is done by using the lowpass filters to
feedback and correct only DC offset while allowing +80dB of gain
to the signal to be taken.



5,646,575
Composite precision, high-frequency
rail-to-rail amplifier

A composite amplifier is constructed by connecting the respective input terminals
of a high-frequency amplifier and a precision amplifier together
and by connecting the output of the precision amplifier
to the offset trim port of the high-frequency amplifier.
The amplifiers are structured such...
5646575.jpg
One can have the best of both worlds by using a precision low
frequency amplifier to "trim" out the offset error of a much
higher frequency amplifier. Such composite are not uncommon.
But if the precision amplifier happens to be a chopper style
amplifier with no 1/f, then it can also trim out the 1/f noise.
5646575b.jpg
If however both the high frequency amplifier and precision amplifier
are build on the same silicon, then it is possible to match the
frequency responses to each other such that together the whole
amplifier looks like a perfect amplifier with no offset, no 1/f noise,
with high frequency response, and with the transfer function looking
like a single one pole rolloff.



5,644,264
Output circuit with short circuit protection
for a CMOS comparator

An output stage of a CMOS comparator is designed to have a limited short circuit current,
while maintaining maximum output voltage swing and a low quiescent current.
The output stage includes a reference voltage generation circuit,
which generates a gate voltage at the output transistor of...
5644264.jpg
This really is the work of Kwok-Fu Chiu. But I did show some
ways to go about solving problems like this.


5,600,283
DC isolated differential oscillator having
floating capacitor

An oscillator includes a small on-chip floating capacitor
having equal parasitic leakages on each of its two plates.
The oscillator is fully differential and, being responsive only to differential signals,
ignores common mode parasitic leakages of the capacitor.
This feature allows for a...
5600283.jpg
One special feature available in a BiCMOS process is the ability
to do logic while drawing DC current. And given that stray capacitance
are in the femto Farads range, the speed can be high enough at very
low supply currents. This Oscillator is driving both ends of a capacitor
close of both rails. But it is doing so while drawing a small amount of
DC current. All the following logic it drives is set to run with
a low DC current as well. As a result, there are no supply glitches in
this IC like what should be expected with using CMOS logic.

5,546,045
Rail to rail operational amplifier output stage

An integrated circuit output stage is intended for use with an operational amplifier.
The output is capable of driving capacitive load to within a V of the power supply rails.
The complementary output transistors are driven by way of a combination
of buffers and complementary...

5546045.jpg
This patent is really an attempt to combine as many inventions as
possible into a single patent. First off it is a low voltage output
stage which works of of two diodes and a sat. As a result it found
itself being designed into 1.8V applications simply because customers
found it worked so well. Also there is a separate feed forward/output
capacitance network which greatly improved apparent stability. And
last a special natural relationship between geometries was found which
enable the detection of output stage saturation as address all of the
problems associated with it.



5,525,934
Output circuit with short circuit protection
for a CMOS comparator

An output stage of a CMOS comparator is designed to have a limited short circuit current,
while maintaining maximum output voltage swing and a low quiescent current.
The output stage includes a reference voltage generation circuit,
which generates a gate voltage at the output transistor of...
5525934.jpg
This really is the work of Kwok-Fu Chiu. But I did show some
ways to go about solving problems like this.



5,471,175
Input protection circuit for a CMOS comparator
An improved input protection circuit receiving a differential signal
has a small signal input circuit and a large signal input circuit.
The small signal input circuit is active when the differential input signal
has a magnitude not exceeding a predetermined value. The large signal input circuit...

541175.jpg
This really is the work of Kwok-Fu Chiu. But I did show some
ways to go about solving problems like this.



5,471,172
"AB Cascode" amplifier in an input stage
of an amplifier or comparator

An AB Cascode amplifier provides low quiescent current operation,
while maintaining the high gain and wide bandwidth of prior art folded cascode amplifier.
Instead of fixed current sources, the AB cascode amplifier uses variable current sources,
which are biased by a fixed small current source...
5471172.jpg
This really is the work of Kwok-Fu Chiu. But I did show of
the advantages to an AB bias stage.




5,455,535
Rail to rail operational amplifier intermediate stage

An interstage circuit functions to combine a first differential voltage
and a second differential voltage, the first and second differential voltages
being either positive or negative, to produce a current at a single ended output.
A first pair of PNP transistors generates a first current...

5455535.jpg
This patent is another attempt to combine as many inventions as
possible into a single patent. First off this is an AB Bias input
stage for Rail to Rail application which adds to offset and noise
performance. Secondly, there existed a special place of put a capacitor
which at the same time both kill gain at high frequency while
also reducing phase shift. Application engineers said they had to use
negative capacitors to model it. And last the output stage had some
already existing bias transistors with collectors that could be rerouted
to this intermediate stage such that open loop gain can be greatly increased.


5,414,388
Rail to rail operational amplifier input stage
An op-amp incorporates an input stage

composed of two complementary long-tailed transistor pairs
driven in parallel from the input terminals.
A bias supply circuit provides the tail currents
which are proportioned so that the total tail current adds up to a constant sum.
The bias circuit...
5414388.jpg
In this patent only two inventions are being combined into a single patent.
First off a way was needed to steer the tail current between the PNP input
and NPN inputs using high speed vertical NPNs and PNPs. The emitters on the input
transistors therefore needed to be connected to collectors of vertical transistors.
Secondly, because the input transistors were all vertical, they required
clamp diodes to protect them from zenering. The clamp diodes are just transistors.
There was no reason why the collectors of the clamps could not be fed into the
signal path to speed up slew rate during the process of clamping and protecting
the input transistors.



4,550,424
PM Decoder sample and hold circuit

An AM stereo receiver decoder is shown.
An AM detector produces the stereo L+R signal and a PM detector produces the L-R signal.
The PM detector is created from a conventional FM detector that employs ...

4550424.jpg

Fred T.J. Cheng did most of the work here. He was working to get Delco set up
to use the LM1981, and this was one of the circuit we came up with along
those lines.



4,523,156
Anti-distortion anti-transient tone control circuit

A tone control circuit including an amplifier
having a continuously adjustable frequency response control
for varying the effect of low and high frequency filters upon the amplifier,
and incorporating a novel distortion and transient suppression circuit is disclosed.


4523156.jpg
This invention was done before the terms "clicks and pops" came into
existence because this was perhaps the first digitally controlled
tone/volume/balance IC to come into existence.


4,392,016
AM Stereo carrier reinsertion

In an AM stereo radio receiver a filter is coupled to the IF amplifier
and is tuned to the IF carrier frequency.
The filter will ring at the IF and, if desired,
can be incorporated into an oscillator circuit.
The resulting signal acts as a reinserted carrier that will persist ...

4392016.jpg
AM radio stations tend to want to Amplitude Modulate their signal
well beyond 100%. Motorola had enough political clout to encourage
broadcasters to modulate within some reasonable limits. The other
alternative is to find some way to reduce the modulation at the
receiver. This invention is using a type of "insertion lock" method
to synchronize a crystal to be able to make the incoming signal
look like the broadcaster is modulating under 90% when they are
in effect modulating well above 100%.


4,379,208
AM Stereo receiver logic

In an AM stereo radio receiver, a pilot signal is recovered from the phase modulated channel.
The pilot signal is sensed by means of a bandpass filter
tuned to the subaudible signal frequency
and is used to operate a detector-switching amplifier combination.
4379208.jpg
Just like FM Stereo, several factors affect the performance of
an AM Stereo receiver. The fail safe mode is toturn off the
stereo signal before anything can make the reception sound bad.
First off, all AM Stereo stations have a pilot. Second, an AM
stereo station will have a type of phase modulation which should
be within some expected range. Third, the strength of the AM
signal might want to be taken into consideration. Fourth, it
is possible to detect whether the radio is tuned in well enough
for stereo reception.

 

4,375,580
AM Stereo receiver separation control

In AM radio receivers it is desirable to operate the automatic gain control
so that strong signals are actually heard louder than weaker signals.
This means that when AM stereo is incorporated into the radio,
using a limiter and phase demodulator to recover the L-R stereo information,

4375580.jpg
Just like for FM Stereo, the fail safe output for an AM Stereo receiver
is mono. In the automotive market, a "blending" feature was being added
to FM Stereo such that depending on the reception conditions, the stereo
signal could be blended into the mono to optimize listening perception.
This patents is applying a version of that to AM Stereo.


4,362,999
AM Stereo phase modulation decoder

A decoder for obtaining the L-R information in an AM stereo radio receiver.
The decoder is basically a four-quadrant multiplier
that has one pair of inputs driven from a limiter
that operates from the receiver intermediate frequency amplifier.
The limiter also drives a tuned circuit
which in turn drives the other two multiplier inputs
in phase quadrature with the first input pair.

4362999.jpg
The FCC initially chose the Magnavox method for AM Stereo. If they would
have stayed with that decision, detecting an AM Stereo signal using a
Phase Lock Loop would have been interesting. The Magnavox method half
Frequency Modulates their stereo signal and half Phase Modulates the
rest. And their pilot signal is phase modulated +/-287 degrees at
5 Hz. The alternative detection method shown above is to FM decode the
signal and then convert part of it to phase modulation by integrating
the audio within some frequency limits. This method works on any of the
proposed AM Stereo systems.



4,359,693
Full wave amplitude modulation detector circuit

A current comparator is supplied with differential currents
based upon an amplitude modulated radio frequency carrier.
The comparator outputs are summed in a combining stage the output
of which will contain a direct current proportional to the average carrier level
and a current variation which represents the carrier modulation.

4359693.jpg
This patent shows simple yet precise method to full wave rectify
an AM signal.




4,348,602
Current comparator circuit with deadband

A pair of differentially related currents are caused to flow in a pair of current modes.
A symmetrical current mirror is coupled to the nodes and level shifting means
coupled from each node to the current mirror common terminal.
4348602.jpg
When using an FM method to decode PM, the audio output from a FM decoded
signal needs to be converted to PM by integrating it with a capacitor.
The DC term that will naturally exist across that capacitor needs to be
shorted out and in doing will in effect become an active 300 henry inductor.
The internal differential currents in the active inductor can be monitored
for phase signal in excess of the expected value.


4,255,815
Electronic switching for AM-FM radio

An integrated circuit, when operated from a simple single-pole-double throw switch,
performs all of the functions required to switch modes in an FM-AM radio.
The radio frequency circuits are switched directly and,
in response to the AM oscillator circuit state, electronic switching
is employed to switch the FM limiter, AM mixer, and audio amplifier.

4255815.jpg
Putting a power amplifier on the same silicon with the rest of an
AM/FM radio was at first a little scary since it was know at that time
that some audio power amplifiers were radiation enough RF noise
to make their way into the AM receiver. This could be solved by
lowering the gain bandwidth of the power amplifier. But FM reception
needed a higher gain bandwidth in the power amplifier because the
music content had much higher frequencies. This invention simply
switches the gain bandwidth of the power amplifier based on whether
the reception is AM or FM.



4,122,401
High efficiency power amplifier circuit

The invention described herein is essentially a single ended power amplifier circuit
properly biased to avoid crossover distortion
and comprising in its output stage an NPN power transistor
connected between a positive voltage source and a load.

4122401.jpg

During the time when plastic power packages were starting to be developed
for audio power amplifiers, it was common to put output NPN transistors in
a negative feedback loop with lateral PNPs in what was called a PNP
composite. As a result, all audio power amplifiers at the time required a
resistor capacitor network to be connected to the output to prevent
the output from oscillating. With the emergence of automotive audio power
amplifiers, the need was to be able swing within a diode and sat to
the high supply voltage. This required another PNP composite. The invention
shows such a composite that is inherently stable and can put out 5 Amps.



4,069,460
Current comparator circuit

Two currents that are to be compared are coupled to the two input terminals of a current mirror.
The output is taken from a transistor stage which has its input coupled across the current mirror.
In a balanced version the current mirror is made symmetrical
and a balanced output pair is cross coupled across the current mirror,
thus creating a fully symmetrical configuration.
4069460.jpg
A common problem encountered in analog signal processing it to be
able to perform an absolute value function on differential signals.
The invention self biases itself up with any two input currents
and will output the absolute difference between them.



Don Sauer... DSauerSanJose@Aol.com