Abstract: A bandgap reference circuit is described in which two transistors share a current with their bases coupled together and to an output terminal. A pair of resistors is coupled in series between the emitter of one of the transistors and ground, the emitter of the other transistor being coupled to a node between the resistors. A further transistor is coupled between the output terminal and the node with its base coupled to a second node between two further resistors connected in series between the output terminal and ground. The further transistor and resistors allow the circuit to be compensated for higher order temperature dependence.

Abstract: A band-gap voltage reference having reduced output voltage noise. The invention embraces several novel concepts, including the optimization of transistor area ratios as used in the band-gap device, the selection of multiple transistors in the Vbe, the section of the current range for the band-gap device, resistive loads to provide minimum load noise and selective signal filtering before the output amplifier. The resulting device according to the present invention exhibits lower output voltage noise than previous band-gap voltage references, without sacrificing other important voltage reference parameters, such as line regulation, load regulation, temperature coefficient, and stability.

Abstract: A temperature compensated bandgap voltage reference circuit employs an npn transistor based bypass circuit to maintain a constant collector current within the reference circuit. This bypass circuit draws a nominal current from the bandgap voltage reference circuit. The value of this current is set by a bias circuit responsive to changes in the supply voltage. As the supply voltage changes, the bias circuit varies the conductance of a bypass transistor to draw more or less current and thereby maintain the collector current within the reference circuit constant.

Abstract: A two-terminal temperature-compensated current source includes a first transistor having its emitter connected to a first terminal, its base connected to the base of a second transistor, and its collector coupled to a current mirror. The second transistor has its emitter coupled to the first terminal by a first resistor and its collector coupled to the current mirror. A second resistor is coupled between the first terminal and the base of the first transistor. The current mirror is coupled between a second terminal and the collectors of the first and second transistors so that all current supplied to the current mirror from the second terminal flows into the collectors of the first and second transistors. A third transistor has its base coupled to the collector of the first transistor, its emitter coupled to the base of the first transistor, and its collector coupled to the second terminal.

Abstract: A voltage reference circuit including a Brokaw Cell band-gap reference circuit is provided with breakpoint compensation to adjust the temperature coefficient of the reference voltage provided by the Brokaw Cell as a function of temperature. The voltage reference circuit also includes a thermal limit transistor which is biased by a voltage having a positive temperature coefficient. The thermal limit transistor draws a rapidly increasing current when the operating temperature reaches a predetermined value.

Abstract: A current source provides an output current whose magnitude is substantially independent of changes in temperature. In each of three embodiments (50, 100, 120), one or more bipolar transistors are employed to provide a compensating current which is dependent on the base-to-emitter voltages, V.sub.BE, of such bipolar transistors. The compensating current changes with temperature so as to offset changes in the uncompensated output current so that the total output current is substantially independent of V.sub.BE. The three embodiments employ current mirror circuits (10, 122) that provide a current source of simple circuit design that is operable with the use of a single power supply at a relatively low voltage.

Abstract: The reference circuit includes a current mirror for providing first and second current paths for the conduction of respective first and second currents. The current mirror imposes a current level relationship between the first and second currents. A load, preferably resistive, is provided in the first current path for predominantly establishing a predetermined level of the first current. A transistor having a temperature coefficient of a predetermined polarity and a resistor having a temperature coefficient of a complimentary polarity are provided in the second current path for providing temperature compensation. Finally, a load compensation stage is provided in the first and second current paths to provide a thermal compensation feedback path from the transistor and resistor compensation elements to permit stabilization of the first current level with respect to temperature.

Abstract: An apparatus and method for providing a current exponentially proportional to voltage and directly proportional to temperature is disclosed. An output current is provided that is exponentially proportional to amplifier output voltage and directly proportional to temperature for automatic gain control. The output current is applied to an amplifier for varying gain.

Abstract: An integrated-circuit analog-to-digital converter of the successive-approximation type formed on a single monolithic chip. The converter is made by a diffusion process wherein certain portions of the chip are formed with normal-mode linear transistors, and other portions are formed with inverted mode I.sup.2 L transistors. The normal-mode transistors provide a switchable current-source DAC, a set of three-state output buffers, and a comparator. The inverted mode transistors provide an internal clock and successive-approximation control circuitry for the DAC. The chip also includes a voltage reference to provide for absolute analog-to-digital conversions.

Abstract: In a multi-level ECL series gating circuit with three levels of gating which operates over specified operating circuit voltage and operating circuit temperature ranges, provision is made for stabilizing the magnitude of the circuit source current over the operating voltage and temperature ranges by regulating the bias voltage which determines the circuit source current. The bias voltage is regulated according to the inverse of the operating temperature to account for the temperature characteristics of the base-to-emitter diode in the transistor generating the circuit current. The magnitude of the bias voltage over the temperature range never reaches a level which will send the circuit current transistor into saturation at any circuit voltage in the operating range.

Abstract: Circuit for generating a temperature-independent reference voltage includes transistors forming current sources, and a band gap circuit having bipolar transistors and being supplied by the current sources, the ratio of the emitter currents of the bipolar transistors being adjustable. The current sources may further include a first current source and a second current source parallel with the first current source.

Abstract: A load share system which connects to the power outputs of two power supplies to determine any deviation of the output currents relative to each other and provides a correction signal representative of the deviation. The system generates two balance signals of similar magnitude and opposite polarity and delivers one of the balance signals to a sense input of one power supply and the other signal to a sense input of the other power supply to balance the power outputs.

Abstract: A differential voltage, set by threshold differences of a natural FET and an implanted FET, is amplified by a switched capacitor amplifier and filtered by a filtering circuit to provide an accurate reference voltage that is independent of temperature, process variation and power supply voltage changes.

Abstract: A start-up circuit for a voltage regulator having a first current mirror for providing start-up current and a second current mirror responsive to voltage output from said regulator for turning off said first current mirror when said regulator is close to regulation. The circuitry providing start-up current and the circuitry turning off the start-up current having substantially the same temperature coefficients.

Abstract: A JFET circuit generates an adjustable current having a temperature coefficient proportional to I.sub.DSS where I.sub.DSS is the drain current of a JFET when its source and gate are shorted. The JFET has a source terminal coupled to a source of supply voltage. An adjustable resistor is coupled between the gate and source terminals of the JFET. A reference current is supplied to the resistor, which reference current is proportional to the JFET's pinch-off voltage. The desired current appears at the drain of the JFET.

Abstract: A circuit for translating TTL-to-ECL-type signals utilizes an unbuffered emitter-coupled transistor pair for shifting signal levels. The emitter-coupled transistor pair operates by switching a current from a current-source transistor, with the switching being performed against a temperature-compensated threshold voltage that is derived from a reference voltage provided to the current source transistor. Direct, unbuffered switching of the emitter-coupled transistor pair insures rapid, symmetrical response to the TTL signals that drive the transistor pair and produces high-quality, relatively undistorted ECL waveforms. Provision of a current-source reference voltage stabilized with respect to temperature also contributes to reduction of distortion in the ECL waveforms. The threshold voltage is obtained from the current source reference voltage through a current mirror circuit.

Abstract: A thermal shutoff circuit for controlling current to an external circuit in response to changes in the temperature of the shutoff circuit. The thermal shutoff circuit includes a source for supplying a voltage which varies with changes in temperature, and a switch circuit responsive to the temperature variable voltage for interrupting the current to the external circuit when the temperature of the shutoff circuit exceeds a predetermined amount. The switch circuit has a detection transistor having a base connected to the temperature variable voltage source for generating a base current responsive to the temperature variable voltage and a compensation transistor connected in series to the detection transistor for generating an equivalent base current.

Abstract: A circuit for generating a reference voltage with a predetermined temperature drift includes a supply circuit; output terminals; a series circuit connected to the supply circuit and between the output terminals including a network and a circuit for generating an electrical variable having a positive temperature coefficient; and a regulator for negative feedback of an operating point setting having an input circuit connected to the circuit for generating an electrical variable having a positive temperature coefficient and an output circuit connected to the output terminals.

Abstract: The temperature of the power semiconductor component is sensed by a bipolar transistor. The bipolar transistor is in series with a depletion mode MOSFET whose gate and source electrodes are connected together. The drain electrode is also connected to a threshold element. Normally, the FET has low impedance, so that at the input of the threshold element source potential, e.g. ground potential, is present. With current rising as a function of temperature, the current through the FET is limited to a constant, essentially temperature-independent value, and the potential at the input of the threshold element rises steeply. This condition is detected as an overtemperature signal.

Abstract: A device is provided for the temperature measurement and thermal protection of an object and more particularly of an electronic "solid state" circuit, using an analog network representative of a thermal model of the circuit to be protected. It comprises, on the one hand, an initialization device for, at the time of switching on, positioning the state of the thermal model at an operating point representative of the real temperature of the object to be protected and, on the other hand, elements isolating the analog network thus allowing it to be representative of the real thermal state of the circuit to be protected, whatever the state of the circuits internal to said device. The device is appropriate for thermal protection of an electronic power controller.

Abstract: A voltage reference circuit (10) for a constant-current source transistor (16) of the bipolar type provides an output voltage in two components. The first voltage component varies in accordance with the negative temperature coefficient (C.sub.1) of the base (58)-emitter (78) junction of a bipolar transistor (60) to compensate for temperature-related changes in the base (18)-to-emitter (22) voltage of the constant current source transistor. The second voltage component is of fixed magnitude and develops collector current (I.sub.0) flow through the transistor and thereby actuates constant-current source operation. The result is a transistor constant-current source that provides a constant output current independent of temperature.

Abstract: A device for stabilizing an output of a photosensor which uses a light-emitting element and a light-receiving element is disclosed. A resistor is connected in series with the light-emitting element to control a voltage across the series connection of the light-emitting element and resistor to a constant value. The output of the light-receiving element is stabilized against temperature variations without resorting to an extra light-receiving element for compensation.

Abstract: An integrated-circuit analog-to-digital converter of the successive-approximation type formed on a single monolithic chip. The converter is made by a diffusion process wherein certain portions of the chip are formed with normal-mode linear transistors, and other portions are formed with inverted mode I.sup.2 L transistors. The normal-mode transistors provide a switchable current-source DAC, a set of three-state output buffers, and a comparator. The inverted mode transistors provide an internal clock and successive-approximation control circuitry for the DAC. The chip also includes a voltage reference to provide for absolute analog-to-digital conversions.

Abstract: The voltage regulating device, compensating the error due to the heat dissipated by the power element that drives the load, specifically an excitation winding of a motor car battery charging alternator, comprises a control stage including a temperature sensing element and a power stage driven by the control stage for generating an output voltage dependent on the ambient temperature. The power stage includes a sensor for detecting the power dissipated therein and generating a dissipated power signal fed to a compensation section in the control stage which also receives the temperature signal detected by the temperature sensing element for generating an actual ambient temperature signal unaffected by the error due to internal heat dissipation.

Abstract: A control circuit for developing a modulated voltage which is proportional to absolute temperature that includes a thermal current source for producing current having a predetermined temperature coefficient and current steering circuitry for proportionally steering the current between first and second outputs in response to a direct current bias voltage applied thereto wherein the current at the first output of the current steering circuitry flows through a resistor. The resistor is connected between a source of different current operating potential and the first output of the current steering circuitry whereby the voltage developed thereacross due to the current steered therethrough is proportional to absolute temperature.

Abstract: A circuit for providing multiple currents the ratios of which are constant and temperature independent. The circuit includes at least first and second transistors the bases of which are shorted together and whose emitters are interconnected via respective trimmable resistors to a thermal current supply. By driving the transistors with a thermal current and trimming one or the other or both resistors the current ratios can be adjusted and will remain constant as temperature is varied.

Abstract: A fluid flow sensor especially adapted for use in solid state electronic system. The sensor employs a heated thermistor in a first sensing network with a temperature compensation means, the two being connected in common to a sensor point. A second network includes a threshold adjusting means and a diode power supply fluctation circuit connected to a threshold point. The two networks are connected in a bridge circuit across a power supply. The thermistor responds to temperature changes associated with air flow changes to produce a change in circuit condition at the sensor point relative to the threshold point. A utility circuit responds to these changes in circuit condition to provide a desired response. The compensation network includes a plurality of diodes arranged to approximate the response of the heated thermistor to changes in power supply voltage such that the voltage at the threshold point closely tracks the voltage at the sensor point in response to any such changes.

Abstract: In a GaAs integrated circuit, a voltage reference generator includes a pair of Schottky diodes and a first, current-source connected, depletion-mode MESFET coupled in series to conduct current from a ground node to a voltage supply node. The current-source connected FET causes a constant current to flow from the ground node through the diodes, producing a constant voltage drop which generates a constant reference voltage at a reference node between the diodes and FET. A second pair of Schottky diodes is connected in series between the source of the FET and the voltage supply node, in a loop coupling the source to the gate of the FET, to provide a voltage difference Vgs across the FET proportional to voltage drop across the second pair of diodes. This voltage difference varies with fabrication process and temperature variations and causes the first FET to modify the amount of current flow to compensate so as to maintain a constant voltage drop across the first pair of diodes.

Abstract: A voltage supply circuit for supplying a regulated output voltage the magnitude and temperature coefficient of which can be independently controlled. A pair of transistors and associated circuitry develop a voltage proportional to the .DELTA.V.sub.BE of the two transistors which are operated at different current densities and sets a first current through the collector of a third transistor which is proportional to .DELTA.V.sub.BE having a positive temperature coefficient (TC). A second current proportional to the negative temperature coefficient base-to-emitter voltage of the third transistor is generated and combined with the first current to produce a third current having a net negative, zero or positive TC. The third current is used to develop a voltage which is combined with the base-to-emitter voltage of the third transistor to produce the output voltage.

Abstract: A highly stable current source which is protected against high voltage overloads, comprising a loop circuit in which the current of known magnitude Iref passes through a scaler resistor to develop a voltage drop thereacross, which is connected with a floating potential in a loop circuit. A differential amplifier is coupled to differentially measure the voltages across the scaler resistor and the floating potential, and provides an output indicative thereof, which determines Iref. In this arrangement, the voltage drop across the scaler resistor equals the voltage drop across the floating potential, and the current Iref through the scaler resistor remains constant at a known magnitude. Embodiments of both positive and negative current generating circuits are disclosed.

Abstract: A circuit that develops a current having a predetermined temperature coefficient includes a pair of transistors which are supplied equal collector currents but which are operated at different current densities to produce a difference voltage between the emitters thereof that has a predetermined temperature coefficient. A third transistor is biased to sink a collector current the value of which is set by the ratio of the difference voltage to the value of a first resistor which is coupled between the collector and base of the third transistor. A second resistor can be coupled between the base and emitter of the third transistor to an output of the circuit whereby the current flowing from the output has a net temperature coefficient that is determined by the ratio of the value of the first resistor to the value of the second resistor.

Abstract: A temperature insensitive voltage reference is described which can advantageously be implemented using standard CMOS processing techniques. A pair of parasitic bipolar transistors are coupled with appropriate resistors to produce a voltage with a temperature coefficient that is equal in value but of opposite polarity to a zener diode voltage-temperature coefficient. This voltage is then combined with a zener diode voltage to yield the desired output reference voltage.

Abstract: A resistively trimmed current mirror circuit including a diode coupled in parallel to the base-emitter conduction path of a transistor and to which a reference current is supplied to produce a proportional output current at the collector of the transistor. A trimmable resistor is connected in the collector-emitter conduction path of the transistor which is adjusted to vary the output current for a given reference current to trim the ratio between the two currents. By making the reference current a thermal current, i.e., a current whose magnitude is proportional to thermal voltage and inversely proportional to resistance, the trimmed ratio remains temperature independent after being trimmed to a desired value.

Abstract: A voltage reference supply circuit is described that provides temperature compensation over a wide range of temperatures. The circuit includes a plurality of thermistor temperature dependent elements and these thermistor elements are utilized to compensate for the variation in the reference potential voltage of the Zener diode. The compensation is provided by determining the output voltage as a function of the circuit parameters and by varying pre-established resistive values in known ranges until the variations in the output voltage with temperature have been reduced below a predetermined value over the entire prescribed temperature range. Using this procedure, a variation in output voltage over the temperature range of -55.degree. C. to +125.degree. C. can be held within 50 parts per million.

Abstract: A circuit arrangement for compensating for the temperature dependence of the sensitivity and of the null point of a piezoresistive pressure sensor having a temperature sensor thermally coupled thereto. The temperature sensor is coupled to an auxiliary amplifier, in the output circuit of which the feed diagonal of the pressure sensor is connected. The output diagonal of the pressure sensor is connected to an output amplifier, to which a temperature-dependent correction voltage can be applied on the input side via a resistor arrangement. To perform the compensation of the temperature dependence of the sensitivity independently of the temperature dependence of the null point, the resistor arrangement is connected directly to the output of the temperature sensor, preferably via jumpers.

Abstract: A circuit is described for trimming a monolithic PN junction isolated silicon IC. The value of a moderate value resistance network is translated to a current that can be made to have a predetermined temperature coefficient and can be applied to the IC. A voltage regulator is shown in which the output voltage and the temperature coefficient can be independently adjusted both at wafer sort and after assembly.

Abstract: A power supply is provided with a predetermined nonlinear temperature coefficient for float charging sealed lead-acid batteries and providing power to a load. A temperature compensation network in the power supply provides the predetermined nonlinear temperature coefficient by using a linear temperature coefficient element (forward biased silicon diode) and a nonlinear temperature coefficient element (thermistor) in combination. Additionally, an over-voltage protection circuit, to disable the power supply should the output voltage exceed a predetermined value, is disclosed having a second temperature compensation network to compensate for the output voltage variation with temperature of the power supply.

Abstract: A reference voltage generating circuit is constituted by a source of constant current, a power supply having high and low voltage terminals, an emitter follower circuit connected across the high and low voltage terminals, first and second resistors with their one ends respectively connected to the high voltage terminal and the output terminal of the source of constant current and the other ends connected to the input terminal of the emitter follower circuit, a third resistor with one end connected to the high voltage terminal, and a diode with its anode electrode connected to the other side of the third resistor and its cathode electrode connected to the output terminal of the source of constant current.

Abstract: A circuit for generating a reference voltage which is independent of temperature and supply voltage includes a bandgap stage supplying the reference voltage, a first circuit receiving the supply voltage and generating an output voltage being substantially free of variations in the supply voltage, and a second circuit connected to the first circuit and driven by the output voltage, the second circuit being connected to the bandgap stage for supplying a current to the bandgap stage having a characteristic for compensating and eliminating temperature dependencies in the bandgap stage.

Abstract: The temperature sensing circuit includes a source of constant current I.sub.S, a voltage divider R.sub.1, R.sub.2 and an output transistor T.sub.1 whose base collector circuit is connected parallel to the first resistor and whose base emitter circuit is connected parallel to the second resistor. An auxiliary source of current having a positive temperature coefficient is connected in series with the first resistor of the voltage divider to cause a voltage drop thereon having an opposite temperature coefficient than the output voltage U.sub.S generated at the collector-emitter circuit of the output transistor.

Abstract: A current mirror circuit which is not adversely effected by temperature changes and which is able to be operated by a relatively low D.C. power source voltage. The circuit includes a current source connected to the commonly connected bases of two transistors. A level shifting diode-connected transistor is connected between the current source and the collector of one of the two transistors. The base-emitter junction area of this level shifting transistor is greater than that of the first transistor so that the potential of the input node is low. The potential between the collector and emitter of the first transistor is determined by the difference in voltages of V.sub.be of the first transistor and the level shifting transistor. The circuit also includes either an additional current source or an additional level shifting transistor connected to the collector of the second transistor.

Abstract: A voltage compensated bias generator voltage source includes an all NPN active collector load circuit operatively coupled between the line voltage V.sub.cc and the collector of the shunt regulator transistor of the bias generator. The all NPN active collector load circuit logarithmically reduces variation in shunt regulator transistor collector current with variations in the line voltage V.sub.cc. A transistor of the active collector load circuit also provides in combination with an output transistor of the bias generator a Darlington transistor pair of ECL current source voltage V.sub.cs. A temperature variation countervailing third transistor is also operatively coupled in the active collector load circuit to compensate for temperature variation problems introduced by the active collector load circuit itself.

Abstract: A temperature compensated voltage reference circuit adapted for on chip location with integrated bi-polar linear circuits, where a temperature stable reference voltage is required in the range of 1.2 to 2.0 volts DC. The circuitry requires only a low chip area and presents a high AC impedance, a low operating current drain, and requires no high value resistors or capacitors.

Abstract: A circuit for providing temperature compensation to a Hall element is disclosed. The temperature compensation circuit is used to generate control signals which act on the effective thickness of the current channel of the Hall element in a manner so as to oppose changes in the effective thickness of the current channel produced by temperature variations.

Abstract: A temperature compensated voltage reference circuit in which a compensation current is generated by establishing a current through a passive impedance element which varies with temperature in accordance with the transistor voltage equation. This current is proportionately reflected into the output impedance circuit associated with the voltage reference, where it compensates for temperature induced voltage variations. The passive impedance element is adjustable to correct for processing variations, and the compensation circuit requires no voltage supplies other than those typically provided for the reference circuit by itself.

Abstract: In an electronic circuit having a reference voltage generator, a device is provided to stabilize the reference voltage against operating temperature variations. Temperature insensitivity is achieved by interposing a source follower type circuit, having a fuse programmable variable resistance feedback loop, between the generator and the circuitry using the reference voltage level. The present invention is particularly suitable for integrated circuits which employs a single reference potential generating circuit device.

Abstract: The invention comprises an improved on-chip voltage regulator which provides output voltages significantly lower than the band gap voltage of silicon with supply voltages as low as 1.0 volt, with the output voltage fully temperature compensated.

Abstract: An all NPN bandgap voltage reference is provided that includes a Widlar type temperature coefficient compensation circuit. A pair of NPN differentially connected transistors maintain a constant current in the Widlar circuit over variations in power supply voltage V.sub.EE while causing an increase in current in the Widlar circuit as temperature increases for maintaining a constant output voltage.

Abstract: A band-gap reference circuit having a pair of transistors operated at different current densities to produce a positive temperature coefficient (TC) signal proportional to the .DELTA.V.sub.BE of the two transistors and combined with a negative TC voltage derived from the V.sub.BE of one of the transistors to produce a composite signal substantially invariant with temperature. The .DELTA.V.sub.BE signal component is increased in magnitude by connecting resistor string bias circuit to each of the transistors, to effectively multiply the V.sub.BE of each transistor, and thereby multiply the .DELTA.V.sub.BE signal. The composite signal is sensed in the emitter circuits of the two transistors, so that it is unnecessary to access the collectors of the transistors, thereby making it readily possible to use the circuit with CMOS IC devices.

Abstract: A resistance bridge is temperature-compensated to provide acceptable values of sensitivity error and zero input error, by using a temperature-responsive current source from which are derived voltages which modify the bridge supply voltage and the bridge output voltage respectively. The output voltage is also modified to provide an acceptable sensitivity error by means of resistors in a circuit between output connections of the bridge and an output connection of the arrangement as a whole.