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4450368 |
AC Coupled chopper stabilized differential comparator
An ac coupled, chopper stabilized differential comparator circuit characterized receiving a differential signal voltage applied between a signal input terminal and a reference signal input...
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4446438 |
Switched capacitor n-path filter
A switched capacitor N-path filter in which all capacitors that introduce delay in the paths, in that they have memory and are characterized such that the new charge flow into each such capacitor...
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4439693 |
Sample and hold circuit with improved offset compensation
The auto-zeroing technique of this invention comprises two steps. In the first step, the differential amplifier output and negative input are shorted together and the resulting amplifier offset...
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4438354 |
Monolithic programmable gain-integrator stage
A switched capacitor gain stage (110, 120) having a programmable gain factor. This gain factor is determined by the connection of desired gain determining components (14-17; 25-28) contained within...
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4430621 |
CMOS Polarity switch
A linear differential amplifier is fabricated in CMOS and combined with digital control so that an analog input signal can be converted to a selected output polarity. When the amplifier output is...
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4430622 |
Offset correction circuit
This invention provides a scheme for offset correction of a unity gain amplifier used in conjunction with data sampling systems. In the present invention, the offset correction of the feedback...
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4429281 |
Integrator for a switched capacitor-filter
An integrator for use in a switched capacitor-filter, in which switching elements are connected to an input and to an output of an operational amplifier included in the integrator for clamping the...
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4429282 |
Offset-nulled sample-and-hold amplifier
A high performance operational amplifier 12 circuit 10 nulls the offset voltage by means of switched capacitors (C 2 , C 3 ) and holds the signal output 18 during the nulling. Switching is in...
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4423385 |
Chopper-stabilized amplifier
An operational amplifier is provided having two input legs and a reference leg. In order to eliminate any input offset voltage between the two input legs, the reference leg is balanced against the...
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4417160 |
Offset compensation apparatus for biasing an analog comparator
A threshold comparator for use with a dual slope A/D converter has its input potential established at its threshold potential during auto-zeroing. Potential offset means is included in the...
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4404525 |
Switched capacitor gain stage with offset and switch feedthrough cancellation scheme
An operational amplifier gain stage utilizing switched capacitor resistor equivalent circuits is designed utilizing a delayed clock reference signal (φ D , φ D ) in a unique manner, thereby...
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4403195 |
Parasitic insensitive switched capacitor operational amplifier circuit
A switched capacitor operational amplifier circuit which has both AC and DC precision and which substantially eliminates parasitic capacitance effects is provided. The operational amplifier circuit...
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4393351 |
Offset compensation for switched capacitor integrators
An integrator circuit utilizing an operational amplifier (19) and switched capacitor elements (11, 13 and 16) in place of resistors in such a manner as to provide compensation for voltage offsets...
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4392112 |
Low drift amplifier
A differential amplifier is arranged to exhibit substantially no D.C. offset or drift. Input signal is alternately connected to the non-inverting and inverting input terminals of an input...
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4387345 |
Precision gain AC coupled operational amplifier
A precision gain AC coupled operational amplifier circuit utilizing an integrated resistor voltage divider network and switched capacitors is provided. Precise gain is obtained by the use of...
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4383222 |
Half-wave signal isolator with compensator means to reduce temperature-dependent effects
A signal isolator including a coupling transformer with modulate/demodulate switches in series with the primary and secondary windings. The switches are driven in synchronism by an oscillator....
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4377759 |
Offset compensating circuit
An offset compensating circuit is disclosed. The offset compensating circuit is inserted in a negative feedback loop of a circuit to be compensated and includes an integration circuit. The...
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4365204 |
Offset compensation for switched capacitor integrators
An integrator circuit utilizing an operational amplifier and switched capacitor elements in place of resistors in such a manner as to provide compensation for voltage offsets present in the...
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4363977 |
Device for discriminating between two values of a signal with DC offset compensation
A device for discriminating between two values of a signal using DC offset compensation including an automatic gain control circuit, a peak detector circuit and a feedback path from the peak...
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4360784 |
Transformer coupled isolation amplifier
A transformer-coupled isolation amplifier which has a minimally sized transformer, high common mode rejection, and a highly linear response over a wide dynamic range. A first chopper periodically...
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4356450 |
Offset compensating circuit for operational amplifier
Disclosed is an offset compensating circuit for an operational amplifier having its noninverting input terminal supplied with a compensating voltage corresponding to its output voltage obtained...
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4355285 |
Auto-zeroing operational amplifier circuit
A temperature stable bandgap voltage reference source utilizing bipolar transistors biased at different emitter current densities is provided. Switched capacitors are used to input the V be and...
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4348661 |
Self-balancing alarm system
An alarm system includes a security loop comprising a plurality of sensors, a circuit connected to the security loop and an alarm. The circuit is responsive to a change in condition within the...
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4342001 |
Differential amplifier having a low-pass characteristic
The input terminal of a voltage follower is coupled to a point of reference potential via a first capacitor. A second capacitor is alternately connected across a source of input signals and...
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4323852 |
Fast recovery electrode amplifier
A fast recovery audio amplifier for use in electrophysiology and other neurological tests and techniques relating to nerve and muscle functions. The fast recovery amplifier recovers from overload...
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4322687 |
Operational amplifier with improved offset correction
Improved input offset voltage compensation of an amplifier (12) is achieved through the use of a servo loop which is added to electronic switch and capacitor offset compensation circuitry disposed...
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4320347 |
Switched capacitor comparator
An operational amplifier is designed to eliminate the effects of inherent voltage affects when used as a voltage comparator, while maintaining a high slew rate and a fast response time by providing...
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4310243 |
Spectrophotometer with photomultiplier tube dark signal compensation
In a spectrophotometer including a photomultiplier tube and an operational amplifier responsive to the current from the photomultiplier tube for generating a DC voltage proportional to light...
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4306196 |
Operational amplifier with offset compensation
Offset voltage compensation is provided by a feedback capacitor (24) in a feedback loop (20). For periodically resetting the compensation, the signal input terminal (14) is grounded by an...
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4298843 |
Stabilized DC amplifier
A pressure responsive system includes a piezoresistive transducer (10) mounted in a housing (20) with the temperature of the housing and the transducer maintained by heater (22). Operating...
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4297745 |
Gain ranging amplifier
A gain ranging amplifier system is provided for use in the acquisition of data. Voltage offset compensation is utilized to correct errors in the gain ranging amplifier system caused by thermal...
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4297642 |
Offset correction in operational amplifiers
A circuit which includes an operational amplifier (101) and includes switches (104, 106) for cancelling offset buildup in the amplifier in response to a circuit (110) which detects zero crossings...
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4296381 |
Distortion reduction circuit for an inverting feedback amplifier
An amplifier is connected between the inverting and non-inverting inputs of an inverting feedback amplifier to substantially reduce distortion caused by inherent physical properties of the...
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4293819 |
High-speed low-drift operational amplifier
A high-speed low-drift operational amplifier is disclosed in which a coefficient circuit having a voltage gain of more than 1 is formed employing a low frequency operational amplifier with a...
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4290023 |
Voltage offset circuit for auto-zero low voltage amplifier
A voltage offset circuit for use with an amplifier connected to receive low voltage signal inputs and operable for eliminating internal voltage offset errors of the amplifier as well as systemic...
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4282521 |
Regulating circuit for gaseous impurity detector
A method and apparatus for automatically recalibrating a leak detector. A gaseous impurities is detected by means of a corona discharge. This discharge is sampled and a signal that is a function of...
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4276513 |
Auto-zero amplifier circuit with wide dynamic range
An operational amplifier (33) is continuously switched back-and-forth between an auto-zero mode of operation and an accurate amplification mode of operation. During the auto-zero mode of operation,...
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4274056 |
Charge amplifier with minimum offset voltage
A charge amplifier having minimum offset voltage such as for use in processing a signal from a capacitive transducer. The amplifier is arranged to minimize the offset voltage and drift. The...
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4268795 |
Pulsed voltage amplification device with drift correction
A pulsed voltage amplification device with drift correction comprises a main differential amplifier whose non-inverting input is coupled to a pulsed voltage source, this main differential amplifier...
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4262543 |
Magnetic flowmeter having multiple stage amplifier with automatic zeroing
A magnetic flowmeter system includes an automatic zeroing system for a multiple stage amplifier. The zeroing system includes a circuit for sequencing the turn-off time of the zeroing amplifiers...
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4255715 |
Offset correction circuit for differential amplifiers
The output of a differential amplifier, operating as a comparator, is coupled through a first switch to charge a small valued capacitor C 1 . The charge in the small capacitor can be coupled...
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4253033 |
Wide bandwidth CMOS class A amplifier
A CMOS inverter is coupled to drive a bipolar transistor emitter follower which has a field effect transistor load. The load transistor is provided with a d-c bias that causes the circuit to...
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4229703 |
Zero reference and offset compensation circuit
A zero reference and offset compensation circuit for an operational amplifier operating in the inverting mode in order to correct for both current and voltage offset errors. The zero reference and...
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4210872 |
High pass switched capacitor filter section
A high-pass switched capacitor biquadratic filter based on the bilinear z-transform. The filter comprises first and second integrating operational amplifiers connected in series and in combination...
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4195266 |
Commutating signal level translator
A system or circuit for signal level translation by information storage on multiple capacitors subjected to commutation at a frequency higher than the highest preserved frequency component of the...
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4190805 |
Commutating autozero amplifier
An active analog signal processing system preferably embodied as an integrated circuit includes a pair of like amplifiers which are alternately switched between a first signal processing mode and a...
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4152659 |
Low noise differential amplifier
A low noise differential amplifier circuit which requires only two operational amplifiers and which has lower noise than conventional differential amplifiers. An alternate embodiment is disclosed...
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4149119 |
Combined AC-DC electrometer with AC feedback for drift compensation
An electrostatic voltmeter or electrometer which includes a probe sensor element for receiving electrostatic charge from a test surface whose potential level is desired to be measured. The probe is...
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4138649 |
Amplifier system
A low-level dc amplifier includes a first amplification stage having a pair of direct coupled inputs and a pair of outputs direct coupled to the input side of a second amplifier. A first...
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4109308 |
Circuit for converting a.c. voltage into a d.c. voltage
An a.c. to d.c. converter is disclosed which includes two resetable integrators each for sampling an alternate half-wave of the a.c. voltage to be converted. During each alternate half-wave, when a...
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