Inventor Don R. Sauer Address: San Jose, CA 6677808 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... 6614293 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,... 6608526 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... 6518847 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... 6456123 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... 6433637 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... 6392465 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... 6380723 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... 6310467 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... 6208215 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... 6201377 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... 6147552 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... 6121848 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... 6064257 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... 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... 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. 5959498 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... 5926066 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... 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... 5646575 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... 5644264 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... 5600283 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... 5546045 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... 5525934 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... 5471175 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... 5471172 "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... 5455535 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... 5414388 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... 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 ... 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. 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 ... 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. 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, 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. 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. 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. 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. 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. 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.Don Sauer... DSauerSanJose@Aol.com