Abstract: A voltage regulator circuit comprises an amplifier (10) having a first input coupled to a first reference voltage node; a power pass element (20) having a control terminal coupled to an output of the amplifier, an input coupled to a power supply input of the voltage regulator circuit, and an output coupled to an output of the voltage regulator circuit; a feedback circuit (30, 31) having an input coupled to the output of the power pass element and an output coupled to a second input of the amplifier; and a compensation module (60) comprising a transistor (61), wherein a gate or base terminal of the transistor is coupled to a second reference voltage node, a drain or collector terminal of the transistor is coupled to the output of the amplifier, and a source or emitter terminal of the transistor is coupled to the power supply input of the voltage regulator circuit. The voltage regulator circuit is capable to increase the power supply rejection ratio of low drop-out voltage regulators.

Abstract: A power bipolar structure is described having at least one first, one second and one third terminal and including at least one power bipolar transistor having a finger structure coupled to at least one driving block. The power bipolar transistor includes at least one elemental bipolar cell connected to these first, second and third terminals and including at least one power elemental bipolar structure corresponding to a finger of the power bipolar transistor, electrically coupled between the first and second terminals and coupled to a driving section of the driving block by at least one sensing section able to detect information on the operation of the power elemental bipolar structure, the sensing section being in turn coupled to a control circuit and supplying it with a current value as a function of the local temperature of the power elemental bipolar structure.

Abstract: The invention provides a constant current control device and a television including the constant current control device. The constant current control device includes a constant current control module and a switched-mode power supply module used for providing a stable voltage for a load. The constant current control module includes a constant current source unit used for providing a reference current, a constant current control unit used for keeping a current flowing through the load constant as the reference current, and a feedback unit used for keeping the voltage of the constant current control unit constant. The present invention, with a simple circuit structure, implements the objective of precisely controlling a current passing through a load.

Abstract: A circuit arrangement including a first transistor, a second transistor and a third transistor. The first transistor and the second transistor are configured so that the current flowing through the first transistor is proportional to the current flowing through the second transistor and the third transistor. The first transistor, the second transistor and the third transistor are configured to operate in an ohmic mode. The second transistor and the third transistor are coupled in series to each other. The first transistor, the second transistor and the third transistor match each other in at least one characteristic.

Abstract: A low voltage bandgap reference circuit includes a positive temperature coefficient circuit unit, a negative temperature coefficient circuit unit and a load unit, wherein the positive temperature coefficient circuit unit comprises a first differential operational amplifier, a first, second and third transistor, a first resistor, a first and second diode, and the negative temperature coefficient circuit unit includes a second differential operational amplifier, a fourth, fifth and sixth transistor, a second resistor and a third diode. The low voltage bandgap reference circuit provides a current having a positive temperature coefficient characteristics and a current having a negative temperature coefficient characteristics to flow through the load in order to generate a stable reference voltage less affected by the temperature. Therefore, it avoids the problems of the low voltage bandgap reference circuit that can not be activated at low voltage.

Abstract: An embodiment of a driving device is proposed for supplying at least one regulated global output current to a load. The driving device includes programming means for programming a value of the global output current within a global current range. Reference means are provided for supplying a reference voltage, which has a value corresponding to the value of the global output current. Conversion means are then used for converting the reference voltage into the global output current. The conversion means may further include a plurality of conversion units for corresponding partial current ranges, which partition the global current range.

Abstract: A low-dropout linear regulator includes an error amplifier which includes a cascaded arrangement of a differential amplifier and a gain stage. The gain stage includes a transistor driven by the differential amplifier to produce at a drive signal for an output stage of the regulator. The transistor is interposed over its source-drain line between a first resistive load included in a RC network creating a zero in the open loop gain of the regulator, and a second resistive load to produce a drive signal for the output stage of the regulator. The second resistive load is a non-linear compensation element to render current consumption linearly proportional to the load current to the regulator. The first resistive load is a non-linear element causing the frequency of said zero created by the RC network to decrease as the load current of the regulator decreases.

Abstract: An adjustable bandgap reference voltage includes a first circuit for generating IPTAT, a second circuit for generating ICTAT, and an output module configured to generate the reference voltage. The first circuit includes a first amplifier connected to terminals of a core for equalizing voltages across the terminals, where the first amplifier has a first stage that is biased by the current inversely proportional to absolute temperature and is arranged according to a folded setup with first PMOS transistors arranged according to a common-gate setup. The first circuit also includes a feedback stage with an input connected to the first amplifier output. The feedback stage output is connected to the first stage input and to a terminal of the core. The second circuit includes a follower amplifier connected to a terminal of the core and separated from the first amplifier and the output module is connected to the feedback stage.

Abstract: A converting circuit for receiving an input voltage and generating an output current, including: a transistor, coupled to a supply voltage at a drain of the transistor, and a source of the transistor is coupled to a first voltage, and a gate of the transistor is coupled to the input voltage and a fixed voltage; and a resistor, coupled to the input voltage and the gate of the transistor, and the output current flows through the resistor, wherein the output current is related to the fixed voltage, the input voltage and the resistor.

Abstract: Disclosed is bandgap voltage reference generator having a programmable resistor. The programmable resistor can be programmed to provide a proper ratio between the PTAT current and the CTAT current to reduce the effect of process variations on the bandgap voltage. The bandgap voltage reference generator includes a calibration circuit that programs the programmable resistor.

Abstract: According to an embodiment, generating an adjustable bandgap reference voltage includes generating a current proportional to absolute temperature (PTAT). Generating the PTAT current includes equalizing voltages across the terminals of a core that is designed to be traversed by the PTAT current. Generating the adjustable bandgap reference also includes generating a current inversely proportional to absolute temperature (CTAT), summing the PTAT and the CTAT currents and generating the bandgap reference voltage based on the sum of the currents. Equalizing includes connecting-across the terminals of the core a first fed-back amplifier with at least one first stage arranged as a folded setup and including first PMOS transistors arranged according to a common-gate setup. Equalizing also includes biasing the first stage based on the CTAT current. The summation of the PTAT and CTAT currents is performed in the feedback stage of the first amplifier.

Abstract: A band-gap reference circuit is compensated for temperature dependent curvature in its output. A voltage across a diode with a fixed current is subtracted from a voltage across a diode with a proportional to absolute temperature (PTAT) current. The resultant voltage is then magnified and added to a PTAT voltage and a diode's voltage that has a complementary-to-absolute temperature (CTAT) characteristic, resulting in a curvature corrected hand-gap voltage. This allows for the band-gap reference circuit to be trimmed at a single temperature. This allows the circuit to be made with only a single trimmable parameter, which, in the exemplary circuits, is a resistance value.

Abstract: A temperature corrected voltage bandgap circuit is provided. The circuit includes first and second diode connected transistors. A first switched compare circuit is coupled to the one transistor to inject or remove a first current into or from the 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: A voltage generator includes a first transistor, a second transistor, an operational amplifier, a capacitor, a third transistor, a fourth transistor and a first resistor. The operational amplifier includes a first terminal coupled to a second terminal of the first transistor, and a second terminal coupled to a second terminal of the second transistor. The capacitor is coupled between an output terminal of the operational amplifier and a ground terminal. The third transistor is coupled to the first transistor and the output terminal of the operational amplifier. The fourth transistor is coupled to the second transistor, the output terminal of the operational amplifier and the ground terminal. The first resistor is utilized for generating a complementary to absolute temperature voltage according to a voltage difference between a gate-source voltage of the third transistor and a gate-source voltage of the fourth transistor.

Abstract: A band gap reference circuit comprises a first branch (1) having a first transistor (Q1) and a first temperature-dependent resistive element (S0). A second branch of the band gap reference comprises a second transistor (Q2) having a different size compared to the first transistor (Q1). An output branch (3) comprises a second temperature-dependent resistive element (S1, S2), that second temperature-dependent resistive element being coupled to an output terminal (Vref). At least one of the first and second temperature-dependent resistive elements (S0, S1, S2) comprises a transistor (M2) being arranged in a current path of the respective branch (1, 3) and being controlled such that it operates in a linear region of its characteristics.

Abstract: A band gap reference voltage generator has first and second current conduction paths between a first node and a second node. The first current conduction path has first resistive elements in series with a first forward-biased PN junction element. A tap is connected selectively to the first resistive elements through switches that are controllable to select a voltage divider ratio at the tap. The second current conduction path includes a second resistive element in series with a second PN junction element of greater current density than the first PN junction. A voltage error amplifier has inputs connected to the tap and the second PN junction element, and an output for providing a thermally compensated output voltage VREF. A feedback path applies the output voltage VREF through a third resistive element to the first node.

Abstract: A low dropout (LDO) voltage regulator includes a voltage regulation loop for providing a gate drive signal to an output device, the gate drive signal proportional to an output current. The voltage regulation loop includes a current bias input for receiving a bias current. The LDO voltage regulator further includes a current bias control circuit for providing the adaptive bias current at a first value that is proportional to current limit value lab and the width-to-length ratio of transistors of the transconductance amplifier when the output current less than or equal to a threshold and increases the bias current from a threshold to a current limit value. The output current varies substantially linearly over a range of output current values between the threshold and the current limit value.

Abstract: A circuit includes a band-gap reference circuit and a start-up circuit. The band-gap reference circuit includes an operational amplifier, a first current path between a power supply node and a reference node, a second current path between the power supply node and the reference node, and a feedback path between an output of the operational amplifier and the first and second current paths. A first input of the operational amplifier is coupled to the first current path, and a second input of the operational amplifier is coupled to the second current path. The start-up circuit includes a current source and at least one switch coupled between the current source and the band-gap reference circuit. The at least one switch is configured to electrically couple the current source with the first and second current paths during a start-up phase.

Abstract: A current mirror for generating a substantially identical current flow in two parallel current paths, each current path comprising a switching device and each switching device comprising first and second active terminals and a control terminal for controlling current flow between the first and second active terminals, the current mirror comprising a first switching device arranged such that its first active terminal is arranged to receive a first voltage, its second active terminal is arranged to receive a variable voltage that varies independently of the first voltage and its control terminal is arranged to receive a control voltage, a second switching device connected such that its first active terminal is arranged to receive the first voltage and its control terminal is arranged to receive the control voltage and a voltage control device connected to the second switching device such that an input of the voltage control device is connected to the second active terminal of the second switching device, the vo

Abstract: A reference current output device and reference current output method that may adjust a reference current while maintaining a temperature gradient. In the reference current output device and reference current output method of the present invention, a reference current is outputted by a reference voltage and current output circuit, a reference voltage outputted from the reference voltage and current output circuit is converted to an adjustment current and outputted by a conversion and output circuit, the adjustment current is superimposed with the reference current and a superimposed current is outputted by a superimposition and output section.

Abstract: A voltage regulator includes an amplifier, a first buffer and a second buffer. The amplifier is designed to generate an error voltage between a reference voltage and a voltage at an output node of the voltage regulator. The first buffer is coupled to receive the amplified error voltage and, in response, to drive a first pass transistor. The first buffer includes a non-linear resistance element. The resistance of the non-linear resistance element varies non-linearly with a load current drawn from the output node. The second buffer is coupled to receive the amplified error voltage, and in response, to drive a second pass transistor. The second buffer includes a linear resistance element. The resistance of the linear element is a constant. The use of the non-linear resistance element enables reduction in power consumption in the voltage regulator.

Abstract: According to one embodiment, a reference signal generating circuit includes a first nonlinear element that generates a first reference voltage, a second nonlinear element that generates a second reference voltage, a current controlling circuit that controls a current flowing to the first nonlinear element and a current flowing to the second nonlinear element based on an output voltage of the current controlling circuit itself, and N temperature characteristic adjusting elements (N is an integer of 2 or larger) that individually adjust the temperature characteristics of the output voltage of the current controlling circuit.

Abstract: A constant current source has a first current source circuit for outputting a first current; a second current source circuit for outputting a second current according to a reference voltage; a current comparison circuit for comparing magnitudes of the first and second currents; and a current adjustment unit for adjusting a current value of the first current output from the first current source circuit in accordance with a comparison result of the current comparison circuit.

Abstract: Apparatus and methods for current sensing in switching regulators are provided. In certain implementations, a switching regulator includes a switch transistor, a replica transistor, a sense resistor, and a current sensing circuit. The drain and gate of the switch transistor can be electrically connected to the drain and gate of the replica transistor, respectively. The current sensing circuit can generate an output current that varies in response to a sense current from a source of the replica transistor. Additionally, the current sensing circuit can sink the sense current when the sense current flows from the drain to the source of the replica transistor and source the sense current when the sense current flows from the source to the drain of the replica transistor. The sense resistor can receive the output current such that the voltage across the sense resistor changes in relation to the current through the switch transistor.

Abstract: Provided is a voltage reference circuit which is able to obtain high PSRR without a variation in power-supply voltage and an influence of noise. A voltage reference circuit for performing voltage-current conversion on forward voltages of PN junction elements and on a difference therebetween to generate a voltage so as not to depend on a temperature is constituted by an amplifier for controlling a temperature characteristic of a voltage of an output terminal, a source follower circuit for supplying a power to the amplifier, and a PMOS transistor which is controlled by the amplifier and which controls a current to flow into the PN junction elements.

Abstract: In one embodiment, a method includes generating a drive current. Generation of the drive current results in a first leakage current, and the drive current and first leakage current each flow into a first node. The method also includes generating a second leakage current and amplifying the second leakage current to generate a leakage-compensation current. The leakage-compensation current flows away from the first node.

Abstract: An electronic circuit includes a band-gap reference circuit and a start-up circuit. The band-gap reference circuit includes an operational amplifier which has an output and first and second inputs. The band-gap reference circuit is configured to generate a predetermined reference voltage at the output of the operational amplifier after a start-up phase of the band-gap reference circuit. The start-up circuit includes at least one switch arranged to connect at least one current source to at least one of the inputs of the operational amplifier during the start-up phase, and to disconnect the at least one current source from the at least one of the inputs of the operational amplifier after the start-up phase.

Abstract: The present document relates to voltage mirror circuits. A voltage mirror circuit, having an input node and an output node is configured to provide substantially equal voltage levels at the input node and the output node. The voltage mirror circuit comprises an input current source transistor, an input gain transistor arranged in series with the input current source transistor such that the input gain transistor is traversed by the bias current, wherein the voltage level at the input node corresponds to the voltage drop across the input current source transistor and the input gain transistor. An intermediate gain transistor forms a first current mirror with the input gain transistor. An output current source transistor forms a second current mirror with the intermediate current source transistor. An output gain transistor is wherein the voltage level at the output node corresponds to the voltage drop across the output current source transistor and the output gain transistor.

Abstract: A temperature compensation circuit is disclosed. A temperature compensation circuit may include a temperature coefficient generator configured to generate a first signal and a second signal, wherein the first signal is proportional-to-absolute-temperature (ptat) and the second signal is negatively-proportional-to-absolute-temperature (ntat), a first programmable element configured to multiply at a first programmable ratio an amplitude of a third signal having a negative temperature coefficient from a first temperature to a second temperature, and a second programmable element configured to multiply at a second programmable ratio an amplitude of a fourth signal having a positive temperature coefficient from the second temperature to a third temperature.

Abstract: Disclosed is a bandgap reference voltage generator insensitive to changes of process, voltage, and temperature. A bandgap reference voltage generator may detect current having characteristic of CTAT and current having characteristic of PTAT which flow in a current compensation part included in an amplification part, and provide body voltage to one of two input transistors included in the amplification part in response to ratio of the two currents when the ratio is different from the preconfigured reference value. Thus, characteristics according to changes of parameters of elements and change of offset of the amplification part due to changes of PVT may be enhanced, and a characteristic of power supply rejection ratio (PSRR) may be enhanced.

Abstract: A high voltage switching regulator has significantly reduced current sensing delay between measurement of input current and generation of sensed current values, while maintaining good accuracy of the current through a power transistor using current replication and a current conveyor. High sensing accuracy of the input current ensures good load regulation, and low sensing delay ensures fixed duty cycle over a wide range of output currents and high input to output voltage ratios. A current conveyor is used to transfer high side current values to low side control circuits, e.g., pulse width modulation (PWM) control. The current conveyor is always on, e.g., some current flow is always present, thus minimizing any current measurement delay. This is accomplished by dynamically biasing the current conveyor by draining to ground a current equal to the sensed current. Wherein balancing of the current conveyor is ensured and offset at the input of the current conveyor is minimized.

Abstract: The disclosed embodiments of voltage regulators incorporate a current mode control architecture. In one embodiment, a voltage regulator includes a power switch having an input and an output. The power switch is configured to provide a first voltage during a first conduction period and a second voltage during a second conduction period. An output filter is coupled between the power switch output and an output terminal to be coupled to a load. An adjustment device is coupled to sense a current sensing voltage corresponding to a current provided to the output filter. The adjustment device is configured to convert the current sensing voltage to an adjusted current sensing voltage, including replacing a current sensing resistance associated with the current sensing voltage with a reference resistance. Control circuitry includes a current sensing input coupled to the adjustment device to sense the adjusted current sensing voltage, and an output in communication with the power switch input.

Abstract: A bandgap reference voltage generator is provided. In one embodiment, the bandgap reference voltage generator includes a first current generator, a second current generator, and an output voltage generator. The first current generator generates a first current with a positive temperature coefficient. The second current generator generates a second current with a negative temperature coefficient. The output voltage generator generates a third current with a level equal to that of the first current, generates a fourth current with a level equal to that of the second current, adds the third current to the fourth current to obtain a combined current with a zero temperature coefficient, and generates a reference voltage according to the combined current.

Abstract: Systems and methods for managing process and temperature variations for on-chip sense resistors are disclosed. The system includes a circuit that can leverage a linear gm circuit in order to provide linear gains (positive gains and/or negative gains). The linearity of the circuit enables compensation for temperature and process variations across an entire range of current (positive to negative). A control signal is generated by using a linear gm amplifier and a replica resistor, which is substantially similar to the on chip resistor. The control signal is used to control the gain of a disparate linear gm amplifier within a compensation circuit, which provides an offset voltage to compensate for the variation in resistance of the on chip resistor.

Abstract: A switched capacitor voltage reference including a single bias current source, three capacitors, diode devices, an amplifier and switching circuits for developing a temperature independent reference voltage. A single current source avoids having to match multiple current sources. A first capacitor and at least one diode device set a voltage having a negative temperature coefficient. A second capacitor and each of the diode devices set a voltage having a positive temperature coefficient. A third capacitor allows adjustable gain to enable a wide voltage range including a low voltage such as less than one volt. The switching circuits switch between multiple modes for developing and then combining the different temperature coefficient voltages. The topology allows a simple amplifier to be used. The topology is inherently accurate and does not require device trimming. An averaging method may be used to compensate for any mismatch between the diode devices.

Abstract: A circuit comprises a first amplifier and a second amplifier. The first amplifier is configured to amplify a first voltage difference between a first voltage and a second voltage, and to generate a third voltage. The second amplifier is configured to amplify a second voltage difference between the third voltage and an input voltage, and to generate an output voltage. The first voltage is a voltage at a first terminal of a first transistor. The second voltage is a voltage at a second terminal of a second transistor. A first gate of the first transistor is adapted to receive the third voltage. A second gate of the second transistor is adapted to receive the input voltage. Threshold voltage values of the first transistor and the second transistor differ.

Abstract: A bandgap voltage reference circuit for generating a bandgap voltage reference. An embodiment comprises a current generator controlled by a first driving voltage for generating a first current depending on the driving voltage, and a first reference circuit element coupled to the controlled current generator for receiving the first current and generating a first reference voltage in response to the first current. The circuit further comprises a second reference circuit element for receiving a second current corresponding to the first current; said second reference circuit element is adapted to generate a second reference voltage in response to the second current. The circuit further comprises an operational amplifier having a first input coupled to the first circuit element and a second input coupled to the second reference circuit element. The circuit also comprises a control circuit comprising first capacitive element and second capacitive element.

Abstract: A power supply noise rejection circuit for functional circuits, such as a voltage controlled oscillator (VCO). The power supply noise rejection circuit includes an isolation transistor connected to a voltage supply for providing an output current and voltage substantially free of noise across the full frequency range. A current source, a diode connected reference transistor with resistance means connected between its gate and drain terminals, and a dummy circuit serially connected between the voltage supply and ground generate a bias voltage that is applied to the gate of the isolation transistor. The dummy circuit mimics the DC characteristics of the functional circuit such that the output current tracks with process and temperature variations. The isolation transistor and the reference transistor can have negative threshold voltages, and the circuit can include bleed means for drawing current from the gate of the reference transistor and isolation transistor.

Abstract: In accordance with a bandgap circuit and a method of starting the bandgap circuit, a start signal is continuously supplied to a differential amplifier circuit to start up the differential amplifier circuit that controls a bandgap core circuit until the differential amplifier circuit has started up, and then the supply of the start signal to the differential amplifier circuit is discontinued after the differential amplifier circuit has started up.

Abstract: This disclosure relates to a compensating for nonlinearity resulting from a capacitance feedback in current cells of a single ended digital to analog circuit.

Abstract: A regulator for providing a low dropout voltage at an output node of the regulator is provided. An amplifier has a non-inverting input terminal for receiving an input voltage, an inverting input terminal and an output terminal. A first resistor is coupled between a ground and the inverting input terminal of the amplifier. A second resistor is coupled to the inverting input terminal of the amplifier. A first transistor is coupled between a voltage source and the second resistor. A current source coupled between the voltage source and a gate of the first transistor provides a bias current. A second transistor coupled between the first transistor and a current mirror has a gate coupled to the output terminal of the amplifier. The first and second transistors are different type MOS transistors. The replica unit generates the low dropout voltage according to a voltage of the output terminal of the amplifier.

Abstract: A circuit for sensing load current of a voltage regulator. The circuit includes a power transistor and a mirror transistor. A first transistor sizing circuit is coupled to the power transistor and is operable to control size of the power transistor based on a bias voltage of the power transistor, thereby regulating a first voltage for varying load conditions. The circuit also includes a feedback amplifier coupled to the power transistor and the mirror transistor. A transistor is coupled to the feedback amplifier and the mirror transistor. An analog to digital converter (ADC) is coupled to the transistor. A second transistor sizing circuit is coupled to the mirror transistor, the transistor, and the ADC. The second transistor sizing circuit is responsive to an output voltage to control size of the mirror transistor, thereby ensuring that accuracy of output voltage sensed by ADC is not limited by ADC's resolution.

Abstract: A switched capacitor voltage reference including a single bias current source, three capacitors, diode devices, an amplifier and switching circuits for developing a temperature independent reference voltage. A single current source avoids having to match multiple current sources. A first capacitor and at least one diode device set a voltage having a negative temperature coefficient. A second capacitor and each of the diode devices set a voltage having a positive temperature coefficient. A third capacitor allows adjustable gain to enable a wide voltage range including a low voltage such as less than one volt. The switching circuits switch between multiple modes for developing and then combining the different temperature coefficient voltages. The topology allows a simple amplifier to be used. The topology is inherently accurate and does not require device trimming. An averaging method may be used to compensate for any mismatch between the diode devices.

Abstract: Conventional bias circuits exhibit a number of limitations, including the time required to power-up a bias circuit following a low-power state. Large current surges in the supply network induce ringing, further complicating a power-up process. Example embodiments reduce power-up time and minimize current surges in the supply by selectively charging and discharging capacitance to the circuit during power-up and power-down of the bias circuit.

Abstract: A system for use within an integrated circuit (IC) can include an input differential pair including a positive input node and a negative input node, a current source coupled to the input differential pair, and a current mirror. The current mirror can include at least a first active device and a second active device. The system can include a biasing transistor device having a source terminal coupled to a gate terminal of each of the first and second active devices, a gate terminal coupled to a drain terminal of the second active device, and a drain terminal coupled to a voltage source. The biasing transistor device is complementary to the current mirror.

Abstract: A low-voltage source bandgap reference voltage circuit is provided. In the circuit, a differential amplification module (301) is configured to provide negative feedback in a differential input manner, and has one input end connected to a bandgap core module (303), and the other input end connected to an output end of a mirror current module (302) and then connected to the bandgap core module (303); the mirror current module (302) is configured to provide a mirror current for the bandgap core module (303); the bandgap core module (303) is configured to provide a voltage for counteracting positive and negative temperature coefficients; and a starting module (304) is configured to start the low-voltage source bandgap reference voltage circuit, and has one input end connected to an output end of the differential amplification module (301), the other input end connected to a power supply (Vcc), and an output end connected to an output end of the bandgap core module (303) and then grounded.

Abstract: An active matrix electroluminescent display device has an array of current—driven electroluminescent display elements (20), for example comprising organic electroluminescent material, whose operations are each controlled by an associated switching means (10) to which a drive signal for determining a desired light output is supplied in a respective address period and which is arranged to drive the display element according to the drive signal following the address period. Each switching means comprises a current mirror circuit (24, 25, 30, 32) which samples and stores the drive signal with one transistor (24) of the circuit controlling the drive current through the display element (20) and having its gate connected to a storage capacitance (30) on which a voltage determined by the drive signal is stored. Through the use of current mirror circuits improved uniformity of light outputs from the display elements in the array is obtained.

Abstract: A current reference generator including a current network, a bias network, and a loop amplifier. The current network includes first and second transistors of a first conductivity type and third, fourth and fifth transistors of a second conductivity type. The first, third and fifth transistors are series-coupled between voltage supply lines forming a first current path, and the second and fourth transistors are series-coupled between the supply lines forming a second current path. The control terminals of the first and second transistors are coupled together and the control terminals of the third and fourth transistors are coupled together. The bias network biases the fifth transistor. The loop amplifier is coupled to the current network and is operative to maintain constant current level through the first and second current paths independent of voltage variations of the supply lines and at very low supply voltage.

Abstract: A digital-to-analog converter is disclosed. The converter includes a gradient correction module that generates a correction term based on a model of gradient error. The correction term is then applied to the signal path in the digital domain or applied to the output of the digital-to-analog converter in the analog domain. The model used to generate the correction term is based on a vertical gradient error in the array of current source elements, which may be modelled and calibrated using a second-order polynomial. Further, a digital-to-analog converter having a Nyquist DAC and an oversampled DAC is disclosed. When the oversampled DAC is enabled, the resolution of the Nyquist DAC may be increased while slowing the conversion rate.

Abstract: The present invention discloses precharge circuits and methods for DC-DC boost converters. In one embodiment, a precharge method for a DC-DC boost converter having a current mirror circuit that includes a reference transistor and a power transistor, can include: (i) maintaining a reference current flowing through the reference transistor as substantially constant; (ii) maintaining a drain-source voltage of the reference transistor and a drain-source voltage of the power transistor as substantially equal; and (iii) obtaining a substantially constant mirror current by reflecting the reference current through the power transistor to operate as a precharging current of a precharge circuit.