Abstract: A reference voltage generating circuit provides a stabilized reference voltage and includes; a clock generator providing a clock signal, a high voltage generator providing a pumping voltage in response to the clock signal, a ripple eradicator providing a static voltage by removing voltage ripple from the pumping voltage, and a reference voltage generator providing the reference voltage.

Abstract: A bandgap voltage reference circuit is provided with: a feedback circuitry, first and second PN junction elements and first and second resistor elements. The feedback circuitry provides a feedback so as to reduce a voltage between first and second nodes. The first PN junction element is connected between the first node and a ground terminal so as to allow a first current from the first node to the ground terminal to flow in a forward direction of a PN junction. The second PN junction element is connected between the first node and a ground terminal so as to allow a first current from the first node to the ground terminal to flow in a forward direction of a PN junction. The first resistor element is connected between the first node and the first PN junction element, and a second resistor element is connected between the second node and the second PN junction element.

Abstract: A reference voltage generating circuit for generating a reference voltage includes MOSFETs connected to each other. At least one of the MOSFETs includes a control gate and a floating gate that is made hole-rich or discharged by ultraviolet irradiation, and the reference voltage generating circuit is configured to output the difference between threshold voltages of a pair of the MOSFETs as the reference voltage.

Abstract: The present invention provides a regulator circuit that can fast-respond to a variation in load current and supply a sufficient drive current so as to be capable of generating a stable internal source voltage. The regulator circuit includes a preamplifier circuit that detects and amplifies a different between a reference voltage and an internal source voltage, a clamp circuit that limits the amplitude of an output of the preamplifier circuit, a main amplifier circuit that amplifies the amplitude-limited output of the preamplifier circuit, and a driver circuit that outputs the internal source voltage according to the output of the main amplifier. Even though the internal source voltage varies abruptly, the regulator circuit does not oscillate owing to the effect of the clamp circuit.

Abstract: A first resistance element is coupled between a first rectifying element and an output node at which a reference voltage is generated. Second and third resistance elements are coupled in series between a second rectifying element and the output node. A differential amplifier outputs a control voltage corresponding to a difference between a first voltage generated at a connection point of the first rectifying element and the first resistance element and a second voltage generated at a connection point of the second resistance element and the third resistance element. A control circuit supplies a control current corresponding to the control voltage from the differential amplifier. A start-up circuit causes, by supplying a start-up current to the output node in response to supply of a power supply voltage, transition from a first stable state to a second stable state.

Abstract: A radiation-hardened reference circuit includes a precision voltage reference circuit for generating a current-controlling voltage at first and second terminals, a driver circuit for receiving the current-controlling voltage at first and second terminals and for generating an output reference voltage, and a differential sampling circuit having first and second input terminals coupled to the first and second terminals of the voltage reference circuit, and first and second output terminals coupled to the first and second terminals of the driver circuit.

Abstract: A voltage reference circuit includes three or more current mirrors, an operational amplifier, a voltage buffer, two or more diodes, and one or more resistors. The operational amplifier has two inputs separately coupled to an output of two of the three or more current mirrors and an output coupled to the three current mirrors. The voltage buffer has an input coupled to an output of the other one of the three or more current mirrors and another input coupled to an output of the voltage buffer. Each of the diodes is coupled between the output of the two of the three or more current mirrors and one of ground and a negative supply. The one or more resistors are coupled to an output of one or more of the three or more current mirrors to tune effects of input current and establish a first set absolute voltage and temperature coefficient on a voltage reference.

Abstract: A temperature corrected voltage bandgap circuit is provided. The circuit includes first and second diode connected transistors. A first switched current source is coupled to the one transistor to inject or remove a first current into or from the emitter of that transistor. The first current is selected to correct for curvature in the output voltage of the bandgap circuit at one of hotter or colder temperatures.

Abstract: An irregular voltage detection and cutoff circuit using a bandgap reference voltage generation circuit includes the bandgap reference voltage generation circuit, which generates a bandgap reference voltage from the power-supply voltage, a reference voltage generator, which generates a first reference voltage and a second reference voltage in the same voltage level as the bandgap reference voltage from the power-supply voltage, a voltage detector, which generates a detection voltage from the power-supply voltage, and a comparator, which generates a switching control signal that cuts off the power-supply voltage by comparing the first and second reference voltages with the detection voltage.

Abstract: To provide a variable voltage dividing circuit capable of changing voltage values of a detection point and a release point along with a change in power supply voltage without changing a hysteresis width.

Abstract: A reference buffer circuit provides a reference voltage at an output node and comprises a closed-loop branch comprising an amplifier and first and second MOS transistors and an open-loop branch comprising a third MOS transistor. A positive input terminal of the amplifier receives an input voltage. A gate of the first MOS transistor is coupled to the output terminal of the amplifier, and a source is coupled to a negative input terminal of the amplifier. A gate of the second MOS transistor is coupled to the drain of the first MOS transistor, a source is coupled to a first voltage source, and a drain is coupled to the source of the first MOS transistor. A gate of the third MOS transistor is coupled to the output terminal of the amplifier, and a source is coupled to the output node.

Abstract: In accordance with an embodiment of the present invention, a bandgap voltage reference circuit includes a plurality of circuit branches, a plurality of resistors and a plurality of switches. The plurality of switches are used to selectively change over time which of the resistors are connected to be within a first one of the circuit branches and which of the resistors are connected to be within a second one of the circuit branches, to thereby reduce the effects that long term drift of the resistors have on a bandgap voltage output (VGO) of the bandgap voltage reference circuit.

Abstract: In accordance with an embodiment of the present invention, a bandgap voltage reference circuit includes a group of X current sources, a plurality of circuit branches, and a plurality of switches. Each of the X current sources (where X?3) produces a corresponding current that is substantially equal to the currents produced by the other current sources within the group. The plurality of circuit branches of the bandgap voltage reference circuit are collectively used to produce a bandgap voltage output (VGO). Each of the plurality of circuit branches receives at least one of the currents not received by the other circuit branches. The plurality of switches (e.g., controlled by a controller) selectively change over time which of the currents produced by the current sources are received by which of the plurality of circuit branches of the bandgap voltage reference circuit.

Abstract: A bandgap voltage reference unit on an integrated circuit (101) includes a proportional-to-absolute-temperature (PTAT) current source (100) coupled to a bandgap voltage reference circuit (200) that includes a plurality of self-cascode MOSFET structures (201-204) that are cascaded together to form a PTAT voltage generator (205). The bandgap voltage reference circuit also includes a complementary-to-absolute-temperature (CTAT) device (260). A PTAT voltage from the PTAT voltage generator is added to a CTAT voltage from the CTAT device to produce an output voltage of the bandgap voltage reference unit, such that the output voltage is the bandgap voltage of the integrated circuit and such that the output voltage does not change with temperature.

Abstract: Disclosed is a reference voltage generating circuit including a constant current circuit which comprises: a first resistive element and a bipolar transistor connected in series between a supply voltage terminal and a constant potential point; a first MOS transistor having a gate connected to a node connecting the first resistive element with the bipolar transistor; a second resistive element connected in series between a source of the first MOS transistor and the constant potential point; a second MOS transistor connected between a drain of the first MOS transistor and the supply voltage terminal; and a third MOS transistor forming a current mirror in conjunction with the second MOS transistor, wherein a constant current generated by the constant current circuit or a current proportional to the generated constant current is converted to a voltage as a reference voltage.

Abstract: A constant-current circuit comprising: a temperature-compensation circuit to output a temperature-compensated first current; and a current-supply circuit to supply a second current to the temperature-compensation circuit, the temperature-compensation circuit including a voltage-multiplication circuit including a first transistor to generate a base-collector voltage obtained by multiplying a base-emitter voltage by a predetermined ratio, a second transistor identical in conductivity type and substantially equal in base-emitter voltage to the first transistor, a first resistor having two ends connected to a first-transistor collector and second-transistor base, respectively, and a second resistor having two ends connected to first and second-transistor emitters, respectively, the first current being output according to a second-transistor collector current, the second current being supplied to a connection point between a second-transistor base and the first resistor, to generate between both ends of the first

Abstract: A reference current generator circuit suitable for low-voltage applications is provided. The generator circuit is fabricated in a chip for generating a precise reference current based on a precise reference voltage and a precise external resistor. The generator circuit provides an equivalent resistance coupled in parallel with the external resistor to provide resistance compensation and reduce the impedance of seeing into the chip from a chip pad. In addition to the resistance compensation, only moderate capacitance compensation is required to enhance the phase margin of the generator circuit, so as to achieve a stable loop. Therefore, chip area and cost can be reduced in low-voltage applications. In addition, the generator circuit reproduces the reference current generated by the external resistor by utilizing current mirrors, so as to eliminate the effect on currents caused by parallel coupling of the equivalent resistance and the external resistor.

Abstract: An integrated circuit includes a bandgap reference generator and a voltage regulator. The bandgap reference generator includes a first current path, and a first bipolar transistor with an emitter-collector path in the first current path. The voltage regulator includes a second current path, wherein the second current path mirrors the first current path; a resistor configured to receive a current of the second current path; a second bipolar transistor with a base and a collector of the second bipolar transistor being interconnected; and a third bipolar transistor connected in series with the second bipolar transistor and the resistor. A base and a collector of the third bipolar transistor are interconnected.

Abstract: An electronic device is provided comprising a driver for light emitting semiconductor devices. The driver includes a first MOS transistor (MN1) coupled with a channel to the light emitting semiconductor device at an output node. The first MOS transistor (MN1) is configured to determine a current through the light emitting semiconductor device (LED). A control loop is provided so as to control the first MOS transistor to maintain the magnitude of the current through the light emitting semiconductor device at a target value when a voltage drop across the first MOS transistor (MN1) changes. A second MOS transistor is coupled to the output node and biased so as to supply an auxiliary current to the output node, when the voltage drop across the first MOS transistor drops below a minimum voltage level and a feedback loop is provided to reduce the current through the light emitting semiconductor device by an amount proportional to the auxiliary current.

Abstract: A voltage source provides a first voltage which is independent of temperature variation and variable, and a voltage step-down circuit provides a second voltage to be subtracted from the first voltage to generate a reference signal. The second voltage has a first temperature coefficient, and the reference signal has a second temperature coefficient. By changing the first voltage, the second temperature coefficient changes accordingly.

Abstract: A band-gap reference voltage is developed by a phase-clocked band-gap circuit including a single PN junction through which first and second constant currents are alternately directed. A current proportional to absolute temperature is selectively added to one of the first and second constant currents to curvature-compensate the developed band-gap reference voltage. The band-gap circuit is calibrated at any desired temperature by interrupting the curvature compensation current and trimming the one constant current to bring the un-compensated band-gap reference voltage into correspondence with a nominal band-gap voltage functionally related to the calibration temperature and circuit component values.

Abstract: A circuit for generating a voltage of a semiconductor memory apparatus includes a control unit that outputs a driving control signal in response to an enable signal and a burn-in signal, a first voltage generating unit that generates and outputs a first voltage in response to the enable signal, and a voltage maintaining unit that maintains the first voltage in response to the driving control signal.

Abstract: In a conventional bias circuit, as a power supply voltage increases, a current supplied to a bandgap reference becomes unstable due to a fluctuation of the power supply voltage, which makes it impossible for the bias circuit to perform stable bias operations in some cases. A bias circuit of the present invention has a bandgap reference, and includes a first current path supplying a drive current to the bandgap reference, and a second current path supplying a current to the bandgap reference for a predetermined period of time after power-on.

Abstract: A voltage supply circuit and a circuit device can reduce the noise in the output of the circuit when the power to the circuit is turned on and off and can shorten the time required to start or stop the operation of the circuit. When the supply of power to signal processing part 10 is started or stopped, reference voltage Vref supplied to signal processing part 10 is varied continuously to reduce the high-frequency noise in the output of signal processing part 10. Also, when the setpoint value of the waveform of reference voltage Vref is generated by digital signal processing in voltage setting part 30, the desired waveform can be generated without being limited by the values of the circuit elements or the circuit configuration. The output noise of signal processing part 10 can be reduced, and the time that reference time Vref varies can be shortened.

Abstract: Provided herein are circuits and methods to generate a voltage proportional to absolute temperature (VPTAT) and/or a bandgap voltage output (VGO) with low 1/f noise. A first base-emitter voltage branch is used to produce a first base-emitter voltage (VBE1). A second base-emitter voltage branch is used to produce a second base-emitter voltage (VBE2). The circuit also includes a first current preconditioning branch and/or a second current preconditioning branch. The VPTAT is produced based on VBE1 and VBE2. A CTAT branch can be used to generate a voltage complimentary to absolute temperature (VCTAT), which can be added to VPTAT to produce VGO. Which transistors are in the first base-emitter voltage branch, the second base-emitter voltage branch, the first current preconditioning branch, the second current pre-conditioning branch, and the CTAT branch changes over time.

Abstract: A semiconductor memory device includes a boosting power supply circuit that boosts a first voltage to a second voltage, which is higher than an external power supply. A first bandgap reference (BGR) circuit operates on the second voltage generated by the boosting power supply circuit. Thereby, the power supply circuit generates a voltage by using a bandgap reference circuit.

Abstract: A current reference circuit is disclosed. A small startup current is defined as the base current into a bipolar transistor with its collector-emitter path connected in series with a resistor between the power supply voltage and ground. This startup current is conducted via a diode-connected MOS transistor in a first leg of a current mirror. Temperature compensation is maintained by a reference leg in the current mirror that includes a bipolar transistor having an emitter area N times larger than that of a bipolar transistor in a second leg of the current mirror, to establish a temperature-compensated current in the reference leg. A compensation capacitor connected between the collector and base of a bipolar transistor in the first leg suppresses oscillation, and can be modest in size due to the Miller effect.

Abstract: A reference voltage generator includes a proportional to absolute temperature (PTAT) current source and a voltage divider. The PTAT current source is capable of providing a first current that is proportional to a temperature. The voltage divider is capable of receiving a second current that is proportional to the first current. The voltage divider is capable of outputting a reference voltage. The reference voltage is substantially independent from a change of the temperature.

Abstract: Circuits, methods, and apparatus that provide voltage references having a temperature independent output voltage that is less then the bandgap of silicon. The temperature coefficient and absolute voltage can be independently adjusted. One example generates two voltages, the first of which is proportional-to-absolute temperature and the second of which is complementary-to-absolute temperature. These voltages are placed across a first resistor. The first resistor is further connected to a second resistor to form a resistor divider. The resistor divider provides a reduced voltage that is below that bandgap of silicon. The temperature coefficient of the reference voltage provided by the resistor divider can be set by adjusting the first resistor. The absolute voltage provided can be set by adjusting the second resistor.

Abstract: An apparatus is disclosed for generating an output signal (e.g., a defined pulse), including a power or current calibration feature. The apparatus comprises a current source adapted to generate a first current to produce the output signal, a current sampling module adapted to generate a second current as a function of (e.g., substantially proportional or equal to) the first current, a reference current module (e.g., a bandgap current source) adapted to generate a third current, and a calibration module adapted to calibrate the first current based on the second and third currents. The current source comprises a plurality of selectable current paths. The current sampling module comprises a replica of at least a portion of one or more current paths of the current source. The calibration module may perform a calibration in response to a defined time, an environment parameter (temperature, voltage, pulse repetition frequency, amplitude requirement change, etc.), or the output signal not being generated.

Abstract: A power-up and power-down circuit for an integrated circuit includes a voltage regulator set for a first voltage. A first I/O pad is coupled internally to an input to the voltage regulator and to first internal circuits. The second voltage is externally coupled to the first I/O pad. A second I/O pad is coupled internally to an output of the voltage regulator configured to drive the base of an external transistor. A third I/O pad of the integrated circuit is coupled internally to a reference-voltage input of the voltage regulator. A fourth I/O pad is coupled to a feedback input of the voltage regulator. A fifth I/O pad of the integrated circuit is coupled internally to logic circuitry that controls power-up and power down of the integrated circuit from internal signals including internal signals from a real-time clock circuit disposed on the integrated circuit.

Abstract: An electronic circuit includes a bandgap reference circuit and a start-up circuit for starting up the bandgap reference circuit. The bandgap reference circuit includes at least one electric path having a semiconductor diode and a resistor connected in series with said semiconductor diode, wherein the voltage across the resistor is proportional to the absolute temperature of the semiconductor diode. The start-up circuit assists starting up the bandgap reference circuit until the voltage across the resistor reaches a preset threshold voltage, and the start-up circuit turns off automatically when the voltage across the resistor has reached the threshold voltage.

Abstract: There are provided a reference signal generator and a PWM control circuit for LCD backlight. The reference signal generator and the PWM control circuit for LCD backlight may be configured to respectively include: a current control unit that controls generation of a variable current sequentially changing; a current generating unit that generates a variable current changing sequentially; and a reference signal generating unit that controls charging until a charged voltage charged by the variable current generated by the current generating unit reaches a first reference voltage level, starts discharging when the charged voltage reaches the first reference voltage level, controls discharging until the charged voltage reaches a second reference voltage level, and generates a triangular wave reference signal that has a frequency buffering interval in which a frequency sequentially changes when the initial driving completion signal or the protection signal is input.

Abstract: A voltage reference source is provided that includes a Brokaw bandgap core comprising a first set of transistors, a second set of transistors coupled to the first set of transistors and serving as load devices to the first set of transistors, and a dynamic element matching circuit coupled to the first and second sets of transistors so as to cancel the offset and noise produced by a selective number of the second set of transistors.

Abstract: A temperature compensated low voltage reference circuit can be realized with a reduced operating voltage overhead and reduced spatial requirements This is accomplished in several ways including integrating one or more bipolar junction transistors into a current differencing amplifier and reducing the number of components required to implement various voltage reference circuits. All of the reference circuits may be constructed with various types of transistors including DTMOS transistors.

Abstract: A circuit adapting pin output levels to a reference level in which a digital comparator compares an output voltage from an output pin of a device to a reference voltage level. The comparator, relying on the polarity of the comparator output as well as the registered polarity of the comparator output on the previous clock cycle, signals a state machine, which sends a clocked signal to a sense circuit and voltage regulator. The sense circuit may modify a resistance in a switched resistor network, such that the output level is incrementally stepped at clocked intervals towards the reference voltage until the polarity of the error signal reverses. When the output voltage crosses the reference voltage threshold, the comparator flips states and continues to regulate output pin voltage to the reference voltage level.

Abstract: An electronic circuit may comprise an input stage powered by a supply voltage and configured to receive a reference signal. The circuit may further comprise an output stage powered by the supply voltage and coupled to the input stage, and configured to generate an error signal based on: the reference signal, and a feedback signal based on an output signal. The circuit may also include a pass transistor powered by the supply voltage and configured to generate the output signal based on the error signal. A capacitor coupled between the supply voltage and the output stage may increase the current flowing in the output stage, resulting in the output stage conducting current even during a rising edge of the supply voltage, preventing the output signal from reaching the level of the supply voltage during the rising edge of the supply voltage.

Abstract: In order to prevent interference of signals in a plurality of outputs from a current mirror circuit, the current mirror circuit comprises a current mirror input transistor Q1 through which a constant current flows and a plurality of current mirror output transistors Q7 and Q8 which have control ends commonly connected to a control end of the current mirror input transistor Q1. The constant current is supplied from the plurality of current mirror output transistors Q7 and Q8 to a plurality of operating circuits. Further, at least one of the plurality of current mirror output transistors Q7 and Q8 is equipped with a low pass filter for removing a high-frequency component contained in a current output from the at least one of the plurality of current mirror output transistors Q7 and Q8.

Abstract: A reference current or voltage generation circuit which forms a self feedback circuit with a plurality of transistors and generates a reference current or a reference voltage, the reference current or voltage generation circuit including a normally-on type transistor that has a gate connected to a first power supply and is connected between a node and a second power supply. Moreover, a voltage of the node is substantially equal to a voltage of the first power supply when the reference current or voltage generation circuit does not operate, and the voltage of the node fluctuates from the voltage of the first power supply toward a voltage of the second power supply by a predetermined value or more when the reference current or voltage generation circuit operates.

Abstract: A current reference circuit includes a proportional-to-absolute temperature (PTAT) current generator, a band-gap reference circuit and a current replication circuit. The PTAT generator generates a PTAT current. The band-gap reference circuit generates a reference voltage based on the PTAT current and generates a second current by cancelling a first current from the PTAT current. The first current has a zero temperature coefficient and the second current has a positive temperature coefficient. The current replication circuit replicates the first current based on the PTAT current and the second current.

Abstract: The present abstract discloses a CMOS bandgap reference source circuit, comprising a startup circuit, a power-off control circuit, a reference voltage generating circuit and an operational amplifier. The positive and a negative input terminal of the operational amplifier both consist of two same field effect transistors and both are provided with an input controlled switch; by doing so, two field effect transistors in the positive terminal and two field effect transistors in the negative terminal work alternately between their strong inversion and cut-off region so as to drastically reduce the noises of the reference circuit, which results originally from the flicker noises of two input transistors of the operational amplifier.

Abstract: An electronic circuit is disclosed. The electronic circuit includes a bandgap circuit provided with first and second bipolar transistors that are coupled at a first node and a current mirror circuit provided with third and fourth transistors with respective control terminals coupled at a second node. The electronic circuit further includes a fifth transistor that is bipolar which is coupled to an output terminal of the third transistor where a base of the fifth transistor is coupled to a collector of the second transistor and a sixth transistor that is bipolar that is coupled to an output terminal of the fourth transistor with a base of the sixth transistor coupled to the first node. A control circuit controls a current provided to the bandgap circuit based on an output of the current mirror circuit. A reference voltage output terminal is provided between the control circuit and the bandgap circuit and outputs a reference voltage.

Abstract: A bandgap voltage reference circuit comprising: a first P-N junction circuit generating a first voltage which changes according to a first characteristic; a second P-N junction circuit generating a second voltage which changes according to a second characteristic different from the first characteristic; an amplifier receiving the first and second voltages at a pair of input terminals and changing the amount of an output current provided from a high-voltage power supply to an output terminal according to a difference voltage between the first and second voltages, wherein an output voltage at the output terminal is provided to the first and second P-N junction circuits; and an output current controller causing the amplifier to provide the output current to the output terminal regardless of the difference voltage when the output voltage equals to or is smaller than a threshold voltage.

Abstract: Inventive embodiments described here provide for accurately distributing a voltage reference to multiple cores of an integrated circuit (IC). A quasi-differential interface is used to transmit the voltage reference, and a virtual ground is established at a receiver located at each core location on the integrated circuit. In one embodiment, the receiver is an operational transconductance amplifier (OTA) that converts a virtual-ground-referenced voltage input to a current. In one embodiment, the OTA converts the virtual-ground-referenced voltage into three currents via three driving current sources operating relative to the virtual ground and the local ground of the core. Negative feedback controls the accuracy of this conversion and provides a way to cancel the effects of the distribution resistance. The current is sourced across the voltage domains between the virtual ground and the VSS, which is the IC ground. An I*R drop across a resistor converts the current to a voltage referenced to VSS at the output.

Abstract: An integrated circuit structure includes a bandgap reference circuit and a start-up circuit. The bandgap reference circuit includes a positive power supply node and a PMOS transistor including a source coupled to the positive power supply node. The start-up circuit is configured to be turned on during a start-up stage of the bandgap reference circuit, and to be turned off after the start-up stage. The start-up circuit includes a switch configured to interconnect a gate and a drain of the PMOS transistor during the start-up stage, and to disconnect the gate of the PMOS transistor from the drain of the PMOS transistor after the start-up stage.

Abstract: Provided herein are circuits and methods to generate a voltage proportional to absolute temperature (VPTAT) and/or a bandgap voltage output (VGO). A circuit includes a group of X transistors. A first subgroup of the X transistors are used to produce a first base-emitter voltage (VBE1). A second subgroup of the X transistors are used to produce a second base-emitter voltage (VBE2). The VPTAT can be produced by determining a difference between VBE1 and VBE2. Which of the X transistors are in the first subgroup and used to produce the first base-emitter voltage (VBE1), and/or which of the X transistors are in the second subgroup and used to produce the second base-emitter voltage (VBE2), change over time. Additionally, a circuit portion can be used to generates a voltage complimentary to absolute temperature (VCTAT) using at least one of the X transistors. The VPTAT and the VCTAT can be added to produce the VGO.

Abstract: A bandgap circuit is provided, which includes a current source, a voltage boost circuit, a voltage input circuit, a voltage equalizer circuit, and a voltage output circuit. The current source provides a first current, a second current, and a third current, which are equal to one another. The voltage boost circuit provides a boost voltage by a single current path. The voltage input circuit receives the first and the second currents, and provides a first input voltage and a second input voltage based on the boost voltage. The voltage equalizer circuit receives the first and the second input voltages and equalize the two input voltages. The voltage output circuit provides a bandgap reference voltage according to the third current.

Abstract: Systems and methods to achieve a startup circuit of bandgap voltage reference generator circuits monitoring a current flow in the bandgap voltage reference generator circuit have been achieved. The startup circuit can operate at supply voltages of about one threshold voltage and is therefore appropriate for low voltage applications. The monitoring of a current through an electrical component inside the bandgap voltage reference generator circuit by replication the component branch in a scaled version saves power and does not disturb the normal operation of the current-mode bandgap voltage reference generator. The startup circuit invented can be applied for current-mode bandgap voltage reference generator circuits as well as for voltage-mode bandgap voltage reference generator circuits.

Abstract: A low-voltage current reference providing a current being substantially constant with temperature includes a low voltage bandgap, a start circuit coupled to the low voltage bandgap, and a current summer coupled to the low voltage bandgap and to the start circuit. The low voltage bandgap is for providing a constant voltage reference, and the start circuit is for starting the low voltage bandgap from a non-start mode and for providing a proportional to absolute temperature (PTAT) current reference. The current summer is for providing a constant current reference according to the constant voltage reference and the PTAT current reference.

Abstract: Circuits, methods, and apparatus that provide voltage references having a temperature independent output voltage that is less then the bandgap of silicon. The temperature coefficient and absolute voltage can be independently adjusted. One example generates two voltages, the first of which is proportional-to-absolute temperature and the second of which is complementary-to-absolute temperature. These voltages are placed across a first resistor. The first resistor is further connected to a second resistor to form a resistor divider. The resistor divider provides a reduced voltage that is below that bandgap of silicon. The temperature coefficient of the reference voltage provided by the resistor divider can be set by adjusting the first resistor. The absolute voltage provided can be set by adjusting the second resistor.