Abstract: An apparatus and a method to reduce temperature dependence of a reference voltage have been presented. In one embodiment, the method includes generating a reference voltage associated with a difference between a first threshold voltage of a first transistor and a second threshold voltage of a second transistor. The method may further include biasing the first transistor and the second transistor at a predetermined ratio of currents of the first and the second transistors to reduce temperature dependence of the reference voltage.

Abstract: An LED driving circuit can improve characteristics. A first current increasing circuit 10i4 is constituted of a first slow regulating unit 10i41 and a post-stage first supplying circuit 10i43 and, from a point in time of output switching of a first comparator 10i2, that is, when a set temperature exceeding a reference potential Va is attained, gradually increases a temperature compensated current IT1 (?I1) and thereby suppresses the lowering of emission output. Here, by gradually increasing the temperature compensated current IT1 by making use of charging/discharging functions of a capacitor, etc., that is, by increasing the temperature compensated current IT1 over a longer time than a pulse width that a photodetecting element, onto which light from an LED 11 is made incident, can respond within, pulse width distortion and jitter can be suppressed.

Abstract: A DC stabilization circuit for an organic electroluminescent display device and a power supply using the same are provided. The DC stabilization circuit includes a self-bias part connected between a first power supply voltage and a reference power supply. The self-bias part generates a bias voltage depending on the first power supply voltage. The circuit also includes a differential part connected to the self-bias part that amplifies a variation in the bias voltage. A negative feedback part is connected to the differential part, adjusts a level of a second power supply voltage using a variable resistor, and compensates for the amplified variation of the bias voltage through a negative feedback operation.

Abstract: An electronic device is provided that is adapted to generate a supply voltage at an input node from a radio frequency (RF) signal. The electronic device includes a limiter coupled to the input node for limiting a supply voltage level at the input node that is generated by the received RF signal. The limiter is configured to draw a limiter current from the input node so as to limit the supply voltage level to a maximum and a magnitude of the limiter current is used for controlling a power consumption of the electronic device.

Abstract: Embodiments of the invention include a temperature sensor method for providing an output voltage response that is linear to the temperature of the integrated circuit to which the temperature sensor belongs and/or the integrated circuit die on which the temperature sensor resides. The output voltage of the temperature sensor has an adjustable gain component and an adjustable voltage offset component that both are adjustable independently based on circuit parameters. The inventive temperature sensor includes an offset circuit that diverts a portion of current from the scaled PTAT current before the current is sourced through the output resistor. The offset circuit includes a bandgap circuit arrangement, a voltage to current converter arrangement, and a current mirror arrangement that are configured to provide a voltage offset adjustable based on independent circuit parameters such as resistor value ratios and transistor device scaling ratios.

Abstract: A system and method are provided for a PTAT cell with no resistors which can operate at low power, has less sensitivity to process variation, occupies less silicon area, and has low noise. Further, a system and method are provided to scale up the reference voltage and current through a cascade of unit cells. Still further, a system and method are provided for PTAT component to be fine-tuned, advantageously providing less process variability and less temperature sensitivity.

Abstract: A system and method for extending the operating life of a device susceptible to defects caused by total ionizing dose radiation and/or bias dependent degradation are described. The device is replicated at least once and at least one switching mechanism is used to cycle between the devices such that only one device is operating normally. While the first device is operating normally, the other devices are biased. The bias condition may slow, eliminate, or even reverse device shifts that occur due to total ionizing dose radiation or bias effects.

Abstract: A method and apparatus are described for providing a current mirror type high voltage switching circuit (60) having a reference branch (M2, M3, R1) and a tracking branch (M1, M5), where the output peak current is limited by adding an additional branch (M4, M6) to the current mirror circuit which includes an additional mirror transistor (M4) and cascode transistor (M6), and where over voltage protection is provided by including a shut-off circuit (Q1, Q2) which turns “OFF” the cascode transistors (M5-M8) whenever the output voltage (Vout) exceeds the first reference voltage (Vbat) by a predetermined amount.

Abstract: A device for providing a substantially constant current includes first and second current mirrors. The first current mirror receives a first amount of a first bias current and provides an output current based on the first amount of the first bias current, the first bias current being based on a fixed voltage. The second current mirror receives a second bias current and a second amount of the first bias current, the second bias current being based on a variable voltage. The second bias current and the second amount of the first bias current vary directly with variations in the variable voltage, and the first amount of the first bias current varies inversely with variations in the variable voltage. The output current remains substantially constant based on the variations in first amount of the first bias current, which counteract effects on the output current by variations in the second voltage.

Abstract: Apparatus and methods provide an operational transconductance amplifier (OTA) with one or more self-biased cascode current mirrors. Applicable topologies include a current-mirror OTA and a folded-cascode OTA. In one embodiment, the self-biasing cascode current mirror is an optional aspect of the folded-cascode OTA. The self-biasing can advantageous reduce the number of biasing circuits used, which can save chip area and cost. One embodiment includes an input differential pair of a current-mirror OTA.

Abstract: A current sensing circuit for sensing the current provided to LEDs by a constant current power source includes a resistive shunt in series with the load and a current mirror having a first leg connected to a first terminal of the resistive shunt and a second leg connected to a second terminal of the resistive shunt. Both legs of the current mirror are also connected to ground. The first leg provides a reference signal to the second leg, and the second log uses the reference signal and a voltage at the second terminal of the resistive shunt to provide a ground referenced output signal indicative of the current provided to the LEDs.

Abstract: Embodiments of the invention may provide for a load regulation tuner that reduces the load regulation effect. The load regulation tuner may include a load current controlled current source that is responsive to a load current from a power transistor of a linear regulator, where the load current controlled current source includes a sensing transistor that generates a fraction of the load current as a sensed partial load current. The load regulation tuner may also include a resistor in parallel with a load current controlled current source, and where the paralleled resistor and the load current controlled current source form at least a portion of a feedback block that adjusts an operation of the linear regulator to provide a substantially constant load voltage.

Abstract: In an embodiment, a current source having a piece-wise linear relationship between current and temperature is provided. The current source includes a first current source to provide current based on a first current-temperature relationship. The current source further includes a second current source coupled in parallel to the first current source. The second current source is to provide current based on a second current-temperature relationship. The current source further includes first mirroring circuitry to mirror a sum of the first current source and the second current source to an output current source. The current source also includes second mirroring circuitry to mirror the sum of the first current source and the second current source for comparison with a third current source. The third current source provides a minimum current magnitude and the third current source is coupled to the second current source to control output of the second current source.

Abstract: Embodiments of the invention describe a reference current generator circuit having a core circuit that includes a first transistor in a first current path for conduct a first current and a second transistor in a second current path for conduct a second current. The second transistor has a threshold voltage that is different from the threshold voltage of the first transistor by at least 10%. The voltage differential between the first and second transistors generate a voltage across a resistive component coupled in series with the second transistor in the second current path.

Abstract: Provided is a voltage control circuit which suppresses a calorific value that generates when short-circuit fault occurs even if a voltage value of an input voltage is large. At the time of short-circuit fault, an additional control voltage Va whose voltage value becomes larger when the voltage value of the input voltage Vin is larger is input to the voltage control p-channel MOS transistor (110) from a transistor control MOS transistor (160), to thereby increase resistance of the voltage control p-channel MOS transistor (110) to suppress a short-circuit current. As a result, when the input voltage Vin is larger, the current value of a holding current or a calorific value after the short-circuit protecting operation has been conducted can be suppressed.

Abstract: Electrical supply apparatus comprising a start-up circuit element coupled to an output element for ensuring reliable start-up when first connected to a source of power. The start-up circuit element comprises first and second branches with current mirror coupling therebetween. The first branch comprises first and second transistors of opposite polarities for connection in series between the source of power and ground and a leakage path to ground in parallel with the second transistor for start-up current for the first transistor of the first branch in response to application of voltage from the source of power. The current mirror coupling between the first and second branches responds to start-up of the first transistor of the first branch to start up a first transistor of the second branch and provide start-up current to the output element.

Abstract: A low-voltage sub-bandgap reference circuit is disclosed. In one embodiment, the low-voltage sub-bandgap voltage reference circuit includes a differential amplifier and a first bipolar transistor with its base and collector coupled to an electrical ground. The reference circuit further includes a second bipolar transistor with base and collector coupled to the electrical ground. The reference circuit further includes a DC bias circuit supplying a predetermined voltage output between a high and low voltage terminal, the high voltage terminal being coupled to both collectors of the first and second bipolar transistors and the low voltage terminal being coupled to both bases of the first and second bipolar transistors.

Abstract: A circuit (200) can include a reference circuit (202) and a start-up circuit (204). A start-up circuit (204) can include a low threshold voltage reference current device (N3) that can pull a start node (210) low in a start-up operation. This can enable activation device (P3), which can place reference circuit (202) in a stable operating mode. Operation of transistor (N3) can be essentially independent of a high power supply voltage and start-up circuit (204) can include no resistors.

Abstract: A stabilizing current source circuit is provided. The stabilizing current source circuit is used for stabilizing a current provided by a current source, and the current of the current source increases when temperature rises. The stabilizing current source circuit comprises a current source circuit and an adjustment circuit. The current source circuit provides a current that increases when temperature rises. The adjustment circuit is coupled to the current source circuit and provides an input current that increases when temperature rises. The current of the current source is subtracted from the input current to generate a current source current which does not vary with temperature.

Abstract: A reference current circuit has an input configured to receive an input current, a first transistor, a second transistor, and an output configured to provide a reference current. The input is directly connected to a control input of the second transistor and a first terminal of the first transistor, and is connected via a first resistor to a control input of the first transistor. The output is connected to a first terminal of the second transistor. A reference node is connected via a second resistor to the control input of the first transistor, directly to a second terminal of the first transistor and via a third resistor to a second terminal of the second transistor.

Abstract: Techniques pertaining to designs of a compensation voltage controlled current source (VCCS) used in low dropout voltage regulators are disclosed. According to one aspect of the present invention, a compensation voltage controlled current source (VCCS) is so designed to meet the low input/output voltage requirements. Various features of the VCCS are demonstrated through several embodiments.

Abstract: A temperature independent type reference current generating device and methods thereof. A temperature independent type reference current generating device may include a first reference current generator generating a first reference current having a first element decreasing according to a temperature, a second reference current generator generating a second reference current having a second element increasing according to the temperature, and/or mirroring and outputting a second reference current and/or a mirrored second reference current. A temperature independent type reference current generating device may include a first current mirror mirroring a first reference current and/or outputting a mirrored first reference current, and a second current mirror adding a mirrored first reference current and a mirrored second reference current, and/or mirroring a result of an addition to output a mirrored result as an output reference current.

Abstract: Embodiments of a cascode amplifier (CA) include a bottom transistor with a relatively thin gate dielectric and higher ratio of channel length to width and a series coupled top transistor with a relatively thick gate dielectric and a lower ratio of channel length to width. A cascode current mirror (CCM) is formed using a coupled pair of CAs, one forming the reference current (RC) side and the other forming the mirror current side of the CCM. The gates of the bottom transistors are tied together and to the common node between the series coupled bottom and top transistors of the RC side, and the gates of the top transistors are coupled together and to the top drain node of the RC side. The area of the CCM can be substantially shrunk without adverse affect on the matching, noise performance and maximum allowable operating voltage.

Abstract: A current minor 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 minor 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 volt

Abstract: A reference current generator for outputting a current proportional to absolute temperature includes a fixed current source transistor, a variable current source transistor and an output transistor which are connected to a drain voltage line. The fixed current source transistor is connected to a source voltage via a series of resistor and first diode. The variable current source transistor is connected to the source voltage via a second diode. A first node between the variable current source transistor and the resistor is connected with a noninverting input of an operational amplifier, and a second node between the variable current source transistor and the second diode is connected with an inverting input of the operational amplifier. The operational amplifier has its output connected to the gate electrode of both the fixed current source transistor and the output transistor, which outputs a PTAT current depending upon the gate voltage.

Abstract: A low drop out series regulator circuit for generating an output voltage that does not rely on voltage feedback or require a capacitor for stable operation includes first and second current sources connected in series between a supply voltage and ground. A resistor is connected between and in series with the first and second current sources, and a reference voltage is generated across the resistor by the current from the first current source. A first transistor is connected between the ground and a first node located between the resistor and the second current source. A current mirror circuit is connected between the supply voltage and the first transistor. A current sense transistor is connected between the current mirror circuit and an output terminal. An output transistor is connected between the supply voltage and the output terminal. The output voltage generated at the output terminal is equal to the reference voltage.

Abstract: Circuits and methods are provided for generating reference currents. In one implementation, a circuit is provided that includes a first source and a current control circuit in communication with the first source. The first source generates a first reference current that is a ratio of a first reference voltage and an external resistance. The current control circuit produces a second reference current that is a ratio of a second reference voltage and the external resistance. The current control circuit produces the second reference current without being directly coupled to the external resistance.

Abstract: Methods and apparatus for higher-order correction of bandgap voltage references are disclosed. An example bandgap voltage reference circuit disclosed herein comprises a bandgap voltage generation circuit comprising a first resistor, the bandgap voltage generation circuit configured to generate a proportional-to-absolute-temperature current to drive the first resistor to produce a first voltage, the first voltage contributing to an output bandgap voltage, and a first correction circuit electrically coupled to the first resistor and configured to provide a first correction current, the first correction circuit comprising a first nonlinear device configured to generate the first correction current only within a first temperature range, the first correction current decreasing with increasing temperature, the first correction current to drive the first resistor to increase the first voltage only within the first temperature range.

Abstract: In a cascode current-mirror circuit which reproduces a reference current generated by a current source and outputs the reproduced reference current: the control electrodes of first and second transistors are connected; a third transistor is cascode-connected to the first transistor through a current electrode; a fourth transistor is cascode-connected to the second transistor; the control electrodes of the third and fourth transistors are connected; the control electrode of a fifth transistor is connected to the control electrode of the first transistor and another current electrode of the third transistor, and is to be connected to the current source; and a bias-voltage generation circuit generates bias voltages for the third and fourth transistors on the basis of voltages of the control electrodes of the first and the fifth transistors.

Abstract: A stabilizing method for a current source is provided. The current source is provided a current which increases when temperature rises. An adjustment circuit provides an input current increasing when temperature rises. A rising ratio of the input current with temperature is the same as a rising ratio of the current of the current source with temperature. The current of the current source is subtracted from the input current. After the current of the current source is subtracted from the input current, the current of the current source does not vary when temperature varies.

Abstract: An electronic device has an LDO regulator for varying loads. The LDO regulator includes a primary supply node coupled to a primary voltage supply. An output node provides a secondary supply voltage and a load current. A bias current source generates a bias current. A gain stage coupled to the bias current source increases the maximum available load current. The gain stage includes a first MOS transistor biased in weak inversion coupled to a current mirror which mirrors the drain current through the first MOS transistor to the output node. The gate-source voltage of the first MOS transistor increases in response to a decreasing secondary supply voltage level at the output node to increase the available load current.

Abstract: A low drop out series regulator circuit for generating an output voltage that does not rely on voltage feedback or require a capacitor for stable operation includes first and second current sources connected in series between a supply voltage and ground. A resistor is connected between and in series with the first and second current sources, and a reference voltage is generated across the resistor by the current from the first current source. A first transistor is connected between the ground and a first node located between the resistor and the second current source. A current mirror circuit is connected between the supply voltage and the first transistor. A current sense transistor is connected between the current mirror circuit and an output terminal. An output transistor is connected between the supply voltage and the output terminal. The output voltage generated at the output terminal is equal to the reference voltage.

Abstract: A BGR circuit includes a temperature-proportional current generating part configured to generate a current in proportion to a change in temperature through a plurality of current paths; a temperature-inverse proportional current generating part generates a current in inverse proportion to a change in temperature through a plurality of current paths. An internal voltage reference voltage generating part generates a reference voltage for an internal voltage using the current of the temperature-proportional current generating part and the current of the temperature-inverse proportional current generating part. A temperature voltage output part outputs a voltage corresponding to a change in temperature.

Abstract: Provided is a band gap reference voltage circuit having an improved power supply rejection ratio. Owing to a voltage supply circuit (51), a power supply voltage (V5) does not depend on variation of a power supply voltage (Vdd). A voltage (V3?V2) which is generated across a resistor (41) and has a positive temperature coefficient is determined based not on the power supply voltage (Vdd) but on the power supply voltage (V5), and hence the voltage (V3?V2) does not depend on the variation of the power supply voltage (Vdd). As a result, the power supply rejection ratio of the band gap reference voltage circuit is improved.

Abstract: A voltage converter to convert a high voltage to a low voltage is provided. The voltage converter comprises: a current mirror, a current bias, a plurality of loads and a low voltage output. The current mirror comprises a first PMOS and a second PMOS, wherein the source of the first PMOS and the second PMOS receive a high voltage input which is a supply voltage of the current mirror, and the gate of the first PMOS is connected to the drain of the first PMOS. The current bias is connected between the drain of the first PMOS and a ground potential. The plurality of loads are parallel connected between the drain of the second PMOS and the ground potential. And the low voltage output connected to the drain of the second PMOS.

Abstract: An output circuit in accordance with one embodiment of the present invention includes: an input terminal for receiving an input signal; an output transistor connected between a first power supply and an output terminal; a current control circuit connected to the input terminal and the output transistor for controlling current outflow and inflow for the gate of the output transistor based on the input signal; a voltage generating circuit connected to the first power supply; and a switch circuit coupled between the gate of the output transistor and the voltage generating circuit, the switch circuit having alternatively an on state and an off state thereof in response to the input signal; wherein the switch circuit becomes the off state when the potential difference between the gate of the output transistor and the first power supply becomes equal to or below a predetermine value regardless of the voltage level of the input signal.

Abstract: The present invention discloses a soft-start circuit having a reference signal generator, a first current generator, a second current generator, and a soft-start capacitor. The reference signal generator generates a first signal and a second signal. The first current generator generates a first current according to the first signal, and the second current generator generates a second current according to the second signal. The soft-start capacitor is coupled to the first current generator and the second current generator, and charged by a current difference of the first current and the second current to generate a soft-start signal.

Abstract: A constant-current circuit includes a first transistor for supplying a current based on a control signal input to a gate of the first transistor so as to serve as a current source, a second transistor for supplying a current to a load based on the control signal input to a gate of the second transistor, a voltage regulation unit for controlling a drain voltage of the first transistor according to a drain voltage of the second transistor, a current detector for detecting a value of a current flowing through the first transistor and output a current according to the detected value, and a controller for controlling each gate voltage of the first and second transistors according to the value detected by the current detector so that the current flowing through the first transistor becomes a predetermined value. The first and second transistors are MOS transistors having the same conductivity.

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: A current mirror with immunity for the variation of threshold voltage includes raising the voltage difference between the gate and the source of a MOS in the current source, and increasing the channel length of the MOS for limiting the generated reference current.

Abstract: A power-on-reset circuit (POR) for integrated circuits that detects the minimum power levels needed to operate the most critical circuit(s) reliably. The circuit is implemented in a customized POR built into a custom IC, and emulates the critical circuit transistors in the custom IC using mimicking counterparts which are similarly affected by changes in temperature and process variations as the main circuit components. The mimicking counterparts may have smaller dimensions, to draw less current but still emulate the characteristics of the main working circuit components. Each critical sub-circuit of the main circuit may have a mimicking POR, and the multiple PORs may have their outputs combined by logic so that subtle failure modes can be modeled in the POR. The POR allows operation of the main circuit to continue at the lowest possible voltage levels while reducing the risk of unexpected results or undetected non-catastrophic failures.

Abstract: To provide a constant current circuit which is capable of not only acquiring characteristics of various sorts of electric circuits even before a trimming adjustment is carried out, performing the trimming adjustment based upon the acquired characteristics, performing trimming processes to both the constant current circuit and a load collectively, and performing an adjustment of a constant current with high precision, but also capable of reducing a total number of manufacturing steps so that a production cost can be lowered, as compared with that of a conventional constant current circuit.

Abstract: A circuit is provided that (in one implementation) includes a first transistor having a first drain terminal, first gate terminal, and a first source terminal. The first drain terminal is connected to the first gate terminal, the first source terminal is connected to a first voltage. The circuit further includes a second transistor having a second drain terminal, second gate terminal, and a second source terminal. The second gate terminal is connected to both the first gate terminal and the first drain terminal, and the second source terminal is connected to the first voltage. The circuit further includes a third transistor having a third drain terminal, a third gate terminal, and a third source terminal. The third drain terminal is connected to the first drain terminal, and the third source terminal is connected to both the third gate terminal and a second voltage that is lower than the first voltage.

Abstract: A current-mode differential transmitter, receiving a single-end input voltage signal and accordingly generating a differential output current signal, is provided. The transmitter includes a first switch, a second switch and a current mirror. The first switch is coupled in a first current path and controlled by the single-end input voltage signal. The second switch is coupled in a second current path and controlled by an inverted signal of the single-end input voltage signal. The current mirror mirrors a reference current to the first current path when the first switch is turned on, and mirrors the reference current to the second current path when the second switch is turned on. The differential output current signal is derived from the currents on the first and second current paths.

Abstract: A bias generator comprises a first transistor and a second transistor having a control port connected to a control port of the first transistor and to an input port of the second transistor, where a second current through the second transistor is greater than a first current through the first transistor. The current through the bias generator is minimized by providing the different currents through the transistors having a similar size.

Abstract: The present invention relates to a transconductance circuit intended to convert a differential input voltage, supplied as two signals to two inputs, IN+ and IN? respectively, into a differential output current. According to the invention, each of the two signals of said differential input voltage is supplied to each input, IN+ and IN? respectively, through a follower transistor, TF+ and TF? respectively, connected to said input, IN+ and IN? respectively, by its emitter and receiving said signal on a control electrode.

Abstract: A current mirror circuit includes a reference current source that generates a reference current, a reference transistor, a mirror transistor and a ratioed body bias feedback unit. The reference transistor has a first node that is coupled to the output of the reference current source, a gate that is coupled to the first node and a second node coupled to a common voltage. The mirror transistor has a gate coupled to the first node. The ratioed body bias feedback unit generates a body bias voltage coupled to the body of the reference transistor and the body of the mirror transistor. The ratioed body bias feedback unit is configured to adjust the body bias voltage in relationship to the common voltage so that the reference transistor and the mirror transistor each have a threshold voltage within a predefined range.

Abstract: A device and a method including current measurement and/or amplification is disclosed. One embodiment provides supplying a current to be measured to a current amplifier. The current is amplified by the current amplifier. The amplified current or a current generated is fed back therefrom to the current amplifier. The current amplifier may include a current mirror. Furthermore, at least one delay means may be used by which the process of current amplification and/or current feedback may be delayed correspondingly.

Abstract: An amplifier circuit is disclosed having an output transistor for driving a complex load over a drive frequency range, wherein in the lower part of the range an inductive component of the load dominates and in the upper part the inductive component does not dominate. The amplifier circuit includes a current mirror circuit that is connected upstream of the output transistor and has a shunt path to a second potential, for the purpose of relatively reducing a DC current flowing through the output transistor in comparison with an AC current flowing through the latter.

Abstract: An all-NPN bipolar junction current mirror circuit for mirroring an input reference current is disclosed. The circuit includes an input stage for providing an input reference current to the current mirror circuit, a reference stage for mirroring the input reference current and an output stage electrically connected to the reference stage for providing the mirrored input current to at least one load.