Entries |
Document | Title | Date |
20080231249 | Integrated circuit current reference - An IC current reference includes a reference voltage V | 09-25-2008 |
20080238401 | METHOD AND APPARATUS FOR ADJUSTING A REFERENCE - A circuit includes a current divider to divide a current from a current source into a first current and a reference current. The circuit also includes a current mirror coupled to the current divider to receive the first current from the current divider and to receive an adjustment current. The adjustment current is to set the reference current. | 10-02-2008 |
20080252282 | REFERENCE CURRENT CIRCUIT - Provided is a reference current circuit able to reduce temperature dependence of the reference current even in a case of using a resistor with extremely low temperature-dependent resistance. The reference current circuit comprises a non-inverting amplifier circuit | 10-16-2008 |
20080284405 | Enhanced Cascode Performance By Reduced Impact Ionization - The conventional cascode circuit can be improved by adding another transistor in series. The added transistor may use the body effect to reduce supply voltage variations across the cascode transistor as the supply voltage varies. The added transistor reduces impact ionization in the cascode transistor. | 11-20-2008 |
20090001959 | CURRENT MIRROR CIRCUIT HAVING DRAIN-SOURCE VOLTAGE CLAMP - A circuit and method for providing an output current that includes biasing an output transistor in accordance with a reference current to conduct the output current and further includes maintaining a voltage across the output transistor. One embodiment includes conducting a reference current through a diode-coupled first field-effect transistor (FET) and biasing a gate of a second FET matched to the diode-coupled first FET by a voltage equal to a gate voltage of the diode-coupled first FET. A current equal to the reference current is conducted through a third FET having a gate coupled to a drain of the second FET, the third FET matched to the second FET. | 01-01-2009 |
20090009152 | BIAS SUPPLY, START-UP CIRCUIT, AND START-UP METHOD FOR BIAS CIRCUIT - A bias supply, a start-up circuit, and a start-up method for a bias circuit are provided. The bias supply includes the bias circuit, a first switch, a second switch, and a charge storage unit. The first switch is coupled between a first voltage and a node. The first switch determines whether or not to be turned on according to a feedback voltage from the bias circuit. The charge storage unit is coupled between the node and a second voltage. The second switch determines whether or not to output a start-up voltage to the bias circuit according to the voltage of the node. In other words, the present invention utilizes charge/discharge properties of the charge storage unit and the feedback voltage from the bias circuit for controlling whether the second switch outputs a start-up voltage to the bias circuit or not. Therefore, the power consumption of the start-up circuit is decreased. | 01-08-2009 |
20090045794 | Stabilizing methods for current source - 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. | 02-19-2009 |
20090066314 | CURRENT MIRROR SEMICONDUCTOR DEVICE AND A LAYOUT METHOD OF THE SAME - A semiconductor device and a layout method of the same reduce a mismatch in a semiconductor device. The semiconductor device includes a first transistor unit providing a first path of current and a second transistor unit designed in a mirror structure to the first transistor unit and providing a second path of current. The layout of the second transistor unit has a shape identical to the first transistor unit and shifted in a first direction. The layout of the semiconductor device reduces a mismatch of the transistors occurring when masks are combined, and thereby reduces their offset. | 03-12-2009 |
20090085550 | Constant current source circuit - A constant current source circuit is constituted of a control voltage generation section which detects the output voltage at the output terminal so as to generate a control voltage, a reference current adjustment section which adjust a reference current based on the control voltage, and a current mirror section which outputs the output current responsive to the adjusted reference current at the output terminal. This reduces variations of the output current due to variations of the output voltage; hence, the constant current source circuit can precisely operate in a low-voltage region. | 04-02-2009 |
20090153126 | CURRENT MIRROR CIRCUIT - The present invention discloses a current mirror circuit generating an output current flowing through an output current path according to an input current flowing through an input current path. The current mirror circuit comprises a P type transistor in the output current path, an operational amplifier, and a basic circuit. The operational amplifier has a negative input coupled to a node receiving the input current, a positive input coupled to a drain of the P type transistor, and an output coupled to a gate of the P type transistor. The basic circuit comprises a first transistor in the input current path and a second transistor in the output current path. The first transistor has a gate and a drain coupled together. The second transistor has a gate coupled to the gate of the first transistor. | 06-18-2009 |
20090160420 | DIFFERENTIAL CURRENT MIRROR CIRCUIT - A differential current mirror circuit includes: a first branching unit that branches current through a first current input terminal to a first current path and a second current path; a second branching unit that branches current through a second current input terminal to a third current path and a fourth current path; and a current mirror that copies current. The current copied by the current mirror is a combination of the current flowing through the second current path and the fourth current path and removal of the in-phase component from current through the first current path enables only the differential component flowing through the first current path to flow to a first current output terminal. Similarly, the in-phase component from current through the third current path is removed, enabling only the differential component flowing through the third current path to flow to a second current output terminal. | 06-25-2009 |
20090184702 | VOLTAGE REGULATOR WITH SELF-ADAPTIVE LOOP - A voltage regulator includes an amplifier and a regulation loop. The regulator includes a first PMOS transistor connected to a terminal supplying an input voltage, a second PMOS transistor connected in series with the first PMOS transistor. A node between those two transistors defines an output terminal. A first source of a first polarization current of fixed value is connected to the gate of the first transistor, and a second source of a second polarization current of fixed value connects the second transistor to ground. A third NMOS transistor is connected between the two current sources. A circuit is provided to modify automatically at least one of the polarization currents in relation to the load current. | 07-23-2009 |
20090189591 | Power Supply Insensitive PTAT Voltage Generator - In temperature sensing circuitry PTAT (Proportional to Absolute Temperature) Voltage References are typically used. By adding a feedback circuit and a source follower into the classic design, the circuit can guarantee that the current is mirrored identically regardless of the value of power supply voltage. This added circuitry is easy to implement and is low in both power and area. The essence of this invention is that the PTAT circuit allows a large range of operation including low voltage (1 Volt) and more accurate temperature readings. | 07-30-2009 |
20090195236 | SEMICONDUCTOR CIRCUITS CAPABLE OF MITIGATING UNWANTED EFFECTS CAUSED BY INPUT SIGNAL VARIATIONS - Semiconductor circuit capable of mitigating unwanted effects caused by variations in a received input signal are provided, in which a main circuit receives an input signal and comprises a first current source coupled between a first node and a first power voltage to generate a first current according to a first bias voltage. A replica circuit is coupled to the main circuit to duplicate a variation in a voltage at the first node caused by a variation in the input signal and dynamically adjusts the first bias voltage according to the duplicated variation such that the first current is maintained at a constant. | 08-06-2009 |
20090201006 | CONSTANT CURRENT CIRCUIT - Provided is a constant current circuit capable of supplying a stable constant current. Even when K values of NMOS transistors vary due to manufacturing fluctuations in semiconductor devices, a voltage generated across a resistor is always a threshold voltage difference between the NMOS transistors, and thus hardly varies. Even when the K values of the NMOS transistors vary due to a change in temperature, the voltage generated across the resistor is always the threshold voltage difference between the NMOS transistors, and thus hardly varies. | 08-13-2009 |
20090267586 | CIRCUIT METHOD FOR PULLING A POTENTIAL AT A NODE TOWARDS A FEED POTENTIAL - A circuit for pulling a potential at a node towards a feed potential present at a potential feed comprises a first transistor comprising controllable paths and a resistive element, wherein the conductive paths of the first transistor and the resistive element are coupled in series between the potential feed and the node. The circuit further comprises a control element configured to control the first transistor to change a resistance of the controllable conductive path of the first transistor depending on a voltage drop at the resistive element. Furthermore, a method for pulling a potential at a node towards a feed potential. | 10-29-2009 |
20090295359 | System and Method for Providing a Low-Power Self-Adjusting Reference Current for Floating Supply Stages - A system and method for providing an accurate current reference using a low-power current source is disclosed. A preferred embodiment comprises a system comprises a first section and a second section. The first section comprises a first simple current reference, an accurate current reference, and a circuit that generates a digital error signal based upon a comparison of an output of the first simple current reference and an output of the accurate current reference. The second section comprises a second simple current reference providing a second reference current, an adjustment circuit providing an adjustment current based upon the digital error signal, and a circuit biased with current equivalent to a summation of the second reference current and the adjustment current. The first simple current reference and the second simple current reference may be equivalent circuits. | 12-03-2009 |
20090295360 | Start-Up Circuit and Method for a Self-Biased Zero-Temperature-Coefficient Current Reference - 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. | 12-03-2009 |
20090302825 | CURRENT SOURCE - A current source includes a node, a biasing circuit, a loading circuit and a current mirror. The node has a specified voltage. The biasing circuit biases the specified voltage to be a first reference voltage. The loading circuit provides an equivalent resistor across the node and a second reference voltage to generate a reference current. The loading circuit includes a resistor and a metal oxide semiconductor field effect transistor (MOSFET). The resistor has a first temperature coefficient. The transistor operating in a linear region is controlled by a control voltage to turn on and to form a transistor resistor coupled with the resistor in series. The transistor resistor has a second temperature coefficient, wherein a temperature coefficient of the equivalent resistor is relevant to the first and second temperature coefficients. The current mirror receives the reference current and provides a mirrored current of the reference current as the output current. | 12-10-2009 |
20100052645 | REFERENCE CURRENT GENERATOR CIRCUIT FOR LOW-VOLTAGE APPLICATIONS - 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. | 03-04-2010 |
20100052646 | CURRENT MIRROR WITH IMMUNITY FOR THE VARIATION OF THRESHOLD VOLTAGE AND THE GENERATION METHOD THEREOF - 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. | 03-04-2010 |
20100072973 | Voltage Converter - 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. | 03-25-2010 |
20100097047 | SERIES REGULATOR CIRCUIT - 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. | 04-22-2010 |
20100117619 | Current-Mirror Circuit - 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. | 05-13-2010 |
20100156387 | TEMPERATURE INDEPENDENT TYPE REFERENCE CURRENT GENERATING DEVICE - 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. | 06-24-2010 |
20100156388 | CASCODE CURRENT MIRROR AND METHOD - 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. | 06-24-2010 |
20100181987 | START-UP CIRCUIT ELEMENT FOR A CONTROLLED ELECTRICAL SUPPLY - 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. The second branch may comprise a control element connected to turn off the second transistor of the first branch on start up of the output element and turn off the first transistors. Alternatively, the start-up circuit may have elements common with the output circuit and remain conductive after the output circuit starts. | 07-22-2010 |
20100231193 | High Side High Voltage Switch with Over Current and Over Voltage Protection - A method and apparatus are described for providing a current mirror type high voltage switching circuit ( | 09-16-2010 |
20100244808 | METHOD AND CIRCUIT FOR LOW POWER VOLTAGE REFERENCE AND BIAS CURRENT GENERATOR - 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. | 09-30-2010 |
20100253315 | POWER LEVEL INDICATOR - 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. | 10-07-2010 |
20100283448 | REFERENCE CIRCUIT WITH REDUCED CURRENT STARTUP - An apparatus is provided. The apparatus comprises a reference circuit and a startup circuit. The reference circuit is adapted to provide a startup current, while the startup circuit receives the startup current and outputs an output voltage. The startup circuit includes a current mirror, a first NMOS transistor, a second NMOS transistor, diodes, and a third NMOS transistor, and a control circuit. The first and second NMOS transistors are coupled to the current mirror at their sources and are coupled to one another and to the reference circuit at their gates. The diodes are coupled between the gate of the second NMOS transistor and the source of the second NMOS transistor, and the third NMOS transistor is coupled to the source of the second NMOS transistor at its gate (which also provides the output voltage at its source). The control circuit is then coupled to the drains of the first and second NMOS transistors. | 11-11-2010 |
20100289475 | LOW DROPOUT REGULATOR COMPENSATION CIRCUIT USING A LOAD CURRENT TRACKING ZERO CIRCUIT - Disclosed is a low dropout regulator that uses a load current tracking zero circuit to stabilize a feedback loop to prevent oscillations. The load current tracking zero circuit senses the DC component of the current flowing through the pass transistor of the low dropout regulator and uses the pass transistor current signal to control a multiplicative factor. The multiplicative factor multiplies the AC variations in the output voltage to generate the zero current. | 11-18-2010 |
20100327843 | Wide-Swing Cascode Current Mirror - A current mirror apparatus includes an input stage receiving an input current, I | 12-30-2010 |
20100327844 | CURRENT MIRROR, DEVICES INCLUDING SAME, AND METHODS OF OPERATION THEREOF - Exemplary embodiments are directed to a current mirror and method of operation thereof. A method may include biasing a first transistor with a voltage at a gate of a second transistor to cause the first transistor to conduct, wherein the first transistor has a source operably coupled to a drain of a third transistor and a drain operably coupled to a gate of the third transistor. The method may also include providing an input current at the drain of the third transistor. Moreover, the method may include decreasing or increasing a voltage at the gate of the first transistor when a voltage at the gate of the second transistor and the drain of the first transistor respectively decreases or increases. Furthermore, the method may include generating an output current in a drain of a fourth transistor having a gate operably coupled to the gate of the third transistor. | 12-30-2010 |
20110050198 | LOW-POWER VOLTAGE REGULATOR - A technique for reducing power dissipation and circuit area for a high voltage application includes creating a low-voltage, local power supply for use with local circuitry. In at least one embodiment of the invention, an apparatus includes an output node configured to provide a regulated output voltage. The apparatus includes a variable current source coupled to a first power supply node, wherein the variable current source is configured to provide an output current to the output node based on a control signal on a control node. The apparatus includes a feedback circuit configured to generate the control signal based on a mirrored current. The mirrored current is a mirrored version of a residual current flowing between the output node and a second power supply node. The regulated output voltage has a voltage level less than the voltage level on the first power supply node. | 03-03-2011 |
20110084682 | PROGRAMMABLE CURRENT MIRROR - A programmable current mirror a reference transistor, first and second mirror transistors, and a first current bypass. The reference transistor has a source and a gate coupled to a reference current node. The first and second mirror transistors are coupled together in series at a first node. Each of the first and second mirror transistors having gates coupled to each other and to the gate of the reference transistor. The first current bypass including a switch disposed in parallel with the second mirror transistor. The first current bypass is coupled to a source and a drain of the second mirror transistor and to the first node. | 04-14-2011 |
20110095745 | POWER SUPPLY CIRCUIT - A power supply circuit includes an output driver transistor, a buffer circuit, and an error amplification circuit. The buffer circuit includes a first transistor connected to an output terminal and a second transistor functioning as a load for the first transistor. The error amplification circuit includes a differential pair including a first pair of transistors, a current mirror circuit including a second pair of transistors, a constant current source supplying a current and driving the differential pair and the current mirror circuit, a third transistor connected between one of the differential pair and the current mirror circuit. The first and second transistor have the same polarity as the transistors constituting the current mirror circuit, and control terminals of the first and third transistors are connected at a first junction node that is connected to a second junction node between the one of the differential pair and the third transistor. | 04-28-2011 |
20110127989 | CONSTANT CURRENT CIRCUIT - Provided is a constant current circuit capable of low current consumption operation, which is prevented from repeating a start-up state and a zero steady state and entering an oscillating state when power is activated. When power is activated, until a node (A) reaches a start-up state, an excitation current is continued to be supplied to a node (B), to thereby reliably start up the constant current circuit in a short period of time without repeating the start-up state and the zero steady state. | 06-02-2011 |
20110187344 | CURRENT-MODE PROGRAMMABLE REFERENCE CIRCUITS AND METHODS THEREFOR - A circuit includes a first current path comprising a first floating-gate transistor having a programmable threshold voltage, a second current path, and a differential amplifier. The second current path includes a second floating-gate transistor having a programmable threshold voltage and a resistor. The differential amplifier includes a first input coupled to the first current path, a second input coupled to the second current path, and an output configured to control a reference current path. | 08-04-2011 |
20110193544 | CIRCUITS AND METHODS OF PRODUCING A REFERENCE CURRENT OR VOLTAGE - A reference circuit includes a first transistor having a first current electrode, a control electrode, and a second current electrode coupled to a power supply terminal. The reference circuit further includes a resistive element including a first terminal coupled to the control electrode of the first transistor and a second terminal coupled to the first current electrode. Additionally, the reference circuit includes a second transistor including a first current electrode coupled to the second terminal of the resistive element, a control electrode coupled to the second terminal, and a second current electrode coupled to the power supply terminal. The second transistor is configured to produce an output signal related to a voltage at the control electrode of the first transistor. | 08-11-2011 |
20110193545 | POWER CONTROL SYSTEM AND POWER AMPLIFICATION SYSTEM USING THE SAME - There is provided a power control system. A power control system may include: a power regulator having a plurality of power PMOS transistors connected to a power source in parallel with each other; a current sensing unit connected to the power source and sensing currents flowing through a plurality of target PMOS transistors located at predetermined positions; a current mirror unit connected to a first regulated voltage terminal and generating a plurality of currents equal to the currents sensed by the current sensing unit; a comparator unit totaling the plurality of currents generated by the current mirror unit to convert the totaled currents into a voltage, and generating a voltage difference between the voltage and a predetermined reference voltage; and a current bias circuit unit controlling a bias current according to the voltage difference from the comparator unit. | 08-11-2011 |
20120001613 | HIGH-BANDWIDTH LINEAR CURRENT MIRROR - High linearity is essential in audio circuitry. As sampling rates for audio applications are needed, high speed and high linearity are needed in analog and mixed signal portions of audio circuitry such as in current mirrors. A current mirror employs two current paths in an output. The first current path is driven by a fast acting transistor through a resistor. The second current path is driven by a differential amplifier coupled to another transistor through another resistor. The second current path is used to maintain linearity by causing the voltage across both transistors to be the same. | 01-05-2012 |
20120074923 | Fast Voltage Regulators For Charge Pumps - A digital multilevel memory system includes a charge pump and a voltage regulator for generating regulated high voltages for various memory operations. The charge pump may include a plurality of boost circuits to boost the output of the charge pump during a fast start up. Afterwards, the boost circuits are disabled to allow the charge pump to generate high voltages without boosting. The boost circuits may be successively enabled to boost the voltage. The boost circuits may be loadless. The voltage regulator may operate in an open loop and may include a resistive divider as a reference voltage for regulating the high voltage from the charge pump. The charge pump may include spread spectrum pump clocking to reduce electromagnetic inference for capacitor or inductor on-chip charge pumping. | 03-29-2012 |
20120105046 | CURRENT MIRROR USING AMBIPOLAR DEVICES - Current mirrors have been used in analog electronics with both CMOS and bipolar transistors for many years. Conventional current minor designs, though, may not be suitable for emerging technology transistors, such as graphene transistors, carbon nanotube (CNT) transistors, or other ambipolar transistors. Here, a current minor has been provided that uses ambipolar transistors, which accounts for the more unusual I-V (drain current to gate-source voltage) characteristics of ambipolar transistors. | 05-03-2012 |
20120139524 | CONSTANT CURRENT CIRCUIT - According to one embodiment, a constant current circuit, including A constant current circuit, a current mirror circuit generating an output current, an external terminal to which an external resistance is connected, a reference current to be supplied to the current mirror circuit depending on the external resistance, a first detection circuit detecting an open state of the external terminal, and an alternative circuit supplying an alternative current corresponding to the reference current into the current mirror circuit when the first detection circuit detects the open state. | 06-07-2012 |
20120161745 | POWER SUPPLY DETECTION CIRCUIT - Power supply detection circuit. The power supply detection circuit includes an input circuit responsive to a core power supply voltage to generate a first output voltage at a first node. The power supply detection circuit also includes a sense logic circuit to sense a voltage drop associated with the first output voltage, when the first output voltage is at a logic level HIGH. Further, the power supply detection circuit includes a current mirror circuit responsive to the voltage drop to increase voltage of the first output voltage to an input and output power supply voltage. Moreover, the power supply detection circuit also includes an output circuit that inverts the first output voltage to generate a second output voltage at a second node. | 06-28-2012 |
20130009623 | FOUR-QUADRANT BOOTSTRAPPED SWITCH CIRCUIT - A bootstrapped switch circuit includes a first switch transistor to receive an input signal and a second switch transistor to provide an output signal. The sources of the switch transistors may be coupled. A voltage source may be coupled to the sources of the switch transistors and at least one of the gates of the switch transistors. The voltage source may generate a control voltage to activate at least one of the switch transistors based on a bias current. A voltage source driver may be coupled to the voltage source to generate the bias current based on a bias voltage. The bias voltage may include a first voltage approximately corresponding to an overdrive voltage of at least one of the switch transistors and a second voltage approximately corresponding to a threshold voltage of the switch transistors. | 01-10-2013 |
20130033251 | SEMICONDUCTOR INTEGRATED CIRCUIT - A semiconductor integrated circuit includes constant current circuit, starter circuit and power supply start-up circuit. In the constant current circuit, first current mirror circuit includes first and second transistors, and second current mirror circuit includes third and fourth transistors that are connected to first and second nodes. In the starter circuit, a potential of first node controls sixth transistor, seventh transistor is connected to third node, gate electrode of the seventh transistor is at ground potential, a capacitance element is connected to fourth node, and a potential of fourth node controls fifth transistor, which supplies start-up current to the constant current circuit via second node. In the power supply start-up circuit, source electrode of eighth transistor is fixed at power supply voltage, gate electrode is at ground potential, and drain electrode supplies power to the other circuits. | 02-07-2013 |
20130099771 | LOW VOLTAGE DETECTION CIRCUIT - Disclosed is a low voltage detection circuit. The low voltage detection circuit includes, a voltage comparison circuit, an output stage, an electric current circuit, and a judgment circuit. When the voltage comparison circuit detects that the voltage of the detection target is a predetermined voltage value or less, an output state of the output stage is promptly changed. When the voltage comparison circuit detects that the voltage of the detection target is a predetermined voltage value or more, the output state of the output stage is changed after a delay time obtained by the electric current circuit. | 04-25-2013 |
20130106395 | System and Method for Providing a Low-Power Self-Adjusting Reference Current for Floating Supply Stages | 05-02-2013 |
20130127438 | PHOTOCOUPLER OUTPUT SIGNAL RECEIVING CIRCUIT - In aspects of the invention, a photocoupler output signal receiving circuit includes a first constant current circuit, connected between an input terminal and the high potential side of a direct current power source, that discharges current, a second constant current circuit, connected between the input terminal and the low potential side of the direct current power source, that takes in current, and switching elements that operate the first and second constant current circuits in a complementary way, wherein the switching elements are operated so that current is taken in by the second constant current circuit after a photocoupler is turned on, and are operated so that current is discharged by the first constant current circuit after the photocoupler is turned off, and a discharge current value in a current discharge period is reduced after a certain period elapses from the start of discharging. | 05-23-2013 |
20130187629 | Dynamic Biasing of an Amplifier Using Capacitive Driving of Internal Bias Voltages - A system and a method are disclosed for using driving capacitors to dynamically bias an amplifier in a stage of a pipeline analog-to-digital converter (ADC). The drain of the amplifier is connected to a sink transistor, and the driving capacitors are used to raise or lower the voltage at the gate of the sink transistor. The driving capacitors can be used in this manner to rapidly power the amplifier on and off to save power and/or to selectively boost the drain current of the amplifier to improve the response time of the pipeline ADC stage. | 07-25-2013 |
20130271106 | Optimization Methodology and Apparatus for Wide-Swing Current Mirror with Wide Current Range - A current mirror circuit includes an input portion configured to conduct a bias current, and a first current source circuit coupled to the input portion and configured to generate the bias current, and vary the bias current over a range of currents based on a first group of weightings associated therewith. The current mirror circuit also includes an output portion configured to conduct an operational current, wherein the output portion is coupled to the input portion, and a second current source circuit coupled to the output portion and configured to generate the operational current, and vary the operational current over a range of currents based on a second group of weightings associated therewith. The first group of weightings and the second group of weightings are different. | 10-17-2013 |
20130320956 | LEVEL SHIFTER CIRCUIT AND GATE DRIVER CIRCUIT INCLUDING THE SAME - There are provided a level shifter circuit and a gate driver circuit including the same. The level shifter circuit includes: a plurality of switching devices connected to a predetermined DC power supply through a resistor and operated by different driving signals; a gain conversion unit operated by first signals output from the plurality of switching devices, respectively, and generating second signals having a level within a predetermined range of the first signals; and a noise removal unit connected to at least one output terminal among the plurality of switching devices to prevent malfunctioning of the gain conversion unit, wherein the gain conversion unit inputs the second signals to a high side gate driver circuit through an inverter circuit. | 12-05-2013 |
20130335057 | Electronic device power protection circuitry - A host electronic device may be coupled to an accessory electronic device. During normal operation, the host device may supply the accessory device with power over a power supply line. Back-powering events in which the accessory device delivers power to the host device may be prevented by interposing a protection transistor in the power supply line. A current mirror may be formed using the protection transistor and an additional transistor that produces a sense current proportional to the amount of current that is flowing through the power supply line. A current-to-voltage amplifier may produce a sense voltage that is proportional to the sense current. A bias circuit may be used to bias the sense current through the current mirror. A control circuit may compare the sense voltage to one or more reference voltages and turn off the protection transistor when appropriate to prevent back-powering of the host device. | 12-19-2013 |
20140117969 | CONSTANT CURRENT SOURCE CIRCUIT - A current source includes a first MOS transistor of a first channel type including a drain connected to an output terminal, and a source directly connected to a first power supply, a second MOS transistor of the first channel type including a drain connected to a gate, the gate of the second MOS transistor being connected to the gate of the first transistor, and a source directly connected to the first power supply, a third MOS transistor of a second channel type opposite the first channel type including a drain connected to the drain of the second MOS transistor, a fourth MOS transistor of the second channel type including a drain connected to the source of the third MOS transistor, a gate connected to a first bias voltage, and a source directly connected to second power supply voltage, and a control voltage generator that detects an output voltage on the output terminal and provides a shifted version of the output voltage to the gate of the third MOS transistor. | 05-01-2014 |
20140145702 | CONSTANT CURRENT GENERATING CIRCUIT USING ON-CHIP CALIBRATED RESISTOR AND RELATED METHOD THEREOF - A constant current generating circuit and constant current generating method applied to a chip are provided, where the chip includes a first current generating circuit and a second current generating circuit, the second current generating circuit includes a transistor and an adjustable resistor. The constant current generating method includes: connecting an external resistor to the first current generating circuit to make the first current generating circuit use the external resistor to generate a first current; utilizing the second current generating circuit to generate a second current; adjusting the adjustable resistor in accordance with the first current and the second current to make the second current substantially equal to the first current, where the second current serves as a constant current of the chip. | 05-29-2014 |
20140218003 | OUTPUT SETTING DEVICE OF CONSTANT CURRENT CIRCUIT - An output setting device of a constant current circuit includes a reference current generation circuit and first to fourth current mirror circuit groups. The reference current generation circuit feeds a reference current. Each current mirror circuit group includes at least one current mirror circuit that feeds a current proportional to the reference current. One current mirror circuit group or two or more current mirror circuit groups connected in parallel to each other among the plurality of current mirror circuit groups are connected to a load to set a current to be supplied to the load. | 08-07-2014 |
20140247035 | NOISE CANCELING CURRENT MIRROR CIRCUIT FOR IMPROVED PSR - A current mirror circuit provides a current to drive a load. A noise cancelling circuit is provided to keep the load current constant in spite of variations in the supply voltage. The noise cancelling circuit includes an auxiliary current path which branches from the load current path. The length-to-width ratios of transistors of the circuit are selected to provide the desired noise cancellation while maintaining device stability. | 09-04-2014 |
20140253088 | FIXED VOLTAGE GENERATING CIRCUIT - A fixed voltage generating circuit includes a current mirror, a differential pair, and a resistor coupled to the current mirror. A node of the resistor is coupled to a voltage source. The differential pair includes two resistors coupled to the voltage source to enable the differential pair outputting a stable output voltage. | 09-11-2014 |
20140333280 | DRIVING DEVICE - A driving device comprises a first transistor (B | 11-13-2014 |
20140340069 | CURRENT GENERATOR CIRCUIT AND METHODS FOR PROVIDING AN OUTPUT CURRENT - Current circuits, circuits configured to provide a bias voltage, and methods for providing a bias voltage are described, including a current circuit configured to receive a reference current and having an output at which an output current is provided. One such current circuit includes a first current mirror configured to receive a first portion of the reference current and further configured to mirror the first portion of the reference current to provide a first current. The current circuit further includes a second current mirror configured to receive a second portion of the reference current and receive the first current. The second current mirror is further configured to provide a portion of the first current to the output of the current circuit as the output current and to receive another portion of the first current and mirror the same as the second portion of the reference current. | 11-20-2014 |
20140368180 | REFERENCE VOLTAGE GENERATOR AND VOLTAGE GENERATING SYSTEM HAVING THE SAME - A reference voltage generator includes a constant voltage generator suitable for using a high voltage as a first power supply voltage and for generating a constant voltage, and a first reference voltage generating unit suitable for using the constant voltage as a second power supply voltage and for generating a first reference voltage. | 12-18-2014 |
20150309527 | TEMPERATURE COEFFICIENT FACTOR CIRCUIT, SEMICONDUCTOR DEVICE, AND RADAR DEVICE - A temperature coefficient factor circuit is provided which generates a current which varies with temperature according to a programmable temperature coefficient factor. The temperature coefficient factor circuit comprises a first current source providing a first current with a positive temperature coefficient factor, a second current source providing a second current with a negative temperature coefficient factor, a common terminal, a first programmable amplifying current mirror, a second programmable amplifying current mirror and a current output circuit. The first programmable amplifying current mirror provides in dependence of a control signal ctrl an amplified first current to the common terminal. The second programmable amplifying current mirror conducts away in dependence of the control signal ctrl an amplified second current from the common terminal. The current output circuit provides the output current based on a difference current between the amplified first current and the amplified second current. | 10-29-2015 |
20150358016 | Current Mirror Circuits with Narrow Bandwidth Bias Noise Reduction - A current mirror circuit includes a first transistor connected to a voltage source, a gate of the first transistor being connected to a drain of the first transistor, a current source connected to the drain and the gate of the first transistor, the current source being configured to generate a predetermined first output current, a sample and hold circuit having an input connected to the gate of the first transistor, a second transistor connected to the voltage source, a gate of the second transistor being connected to an output of the sample and hold circuit, and a controller operatively connected to the sample and hold circuit, the controller being configured to operate the sample and hold circuit at a predetermined sampling frequency to attenuate bias noise from the first transistor in a second output current from the second transistor. | 12-10-2015 |
20150370280 | VOLTAGE REGULATOR WITH IMPROVED LOAD REGULATION - A voltage regulator comprises a ground node, a pick-off node, a regulator branch, a load branch, and a current mirror the regulator branch and the load branch are connected in parallel between the pick-off node and the ground node; the load branch comprises one or more resistive connecting lines that are connectable in series with the load to generate a load current through the load branch; the regulator branch comprises a bias node, a resistive element, and a tap node; the bias node is arranged to provide a regulated bias voltage; the resistive element is connected between the bias node and the pick-off node; and the tap node is connected between the bias node and the resistive element. The current mirror is connected to the tap node and arranged to draw a mirror current from the tap node; the mirror current having a component that is proportional to the load current. | 12-24-2015 |
20150378386 | TRANS-CONDUCTANCE REGULATION CIRCUIT, TRANS-CONDUCTANCE ERROR AMPLIFIER AND POWER CONVERTER - A trans-conductance regulation circuit, a trans-conductance error amplifier module and a power converter. The trans-conductance regulation circuit provides a bias current at least partially based on an output voltage of the power converter. The bias current is sent to bias a trans-conductance operational amplifier in the trans-conductance error amplifier module so that a trans-conductance of the trans-conductance operational amplifier is direct proportional to the output voltage of the power converter. The power converter regulates the output voltage based on a negative feedback loop comprising the trans-conductance error amplifier module. The trans-conductance error amplifier module may help to maintain a band width of the negative feedback loop substantially stable and immune to variations in the output voltage. | 12-31-2015 |
20160026206 | CONSTANT CURRENT SOURCE CIRCUIT - One current source includes a first transistor including a drain connected to an output terminal, and a source directly connected to a first power supply, a second transistor including a drain connected to a gate, the gate of the second transistor being connected to the gate of the first transistor, and a source directly connected to the first power supply, a third transistor opposite the first channel type including a drain connected to the drain of the second transistor, a fourth transistor including a drain connected to the source of the third transistor, a gate connected to a first bias voltage, and a source directly connected to second power supply voltage, and a control voltage generator that detects an output voltage on the output terminal and provides a shifted version of the output voltage to the gate of the third transistor. | 01-28-2016 |
20160070290 | CURRENT FEEDBACK METHOD, CURRENT FEEDBACK CIRCUIT, DRIVING CIRCUIT AND SWITCHING POWER SUPPLY THEREOF - In one embodiment, a current feedback circuit can include: (i) a first current mirror circuit having an input terminal coupled to a source of a main power transistor of a switching power supply, and a control terminal configured to receive a PWM control signal, the first current mirror circuit being configured to generate a first mirror current; (ii) the first current mirror circuit and the main power transistor being on such that an output sampling current flows through the first current mirror circuit and the main power transistor when the PWM control signal is active; and (iii) a second current mirror circuit configured to generate an output feedback current that is in a predetermined direct proportion with the output sampling current, and is generated in accordance with the first mirror current. | 03-10-2016 |
20160070291 | Static Offset Reduction in a Current Conveyor - A voltage mirror circuit, having an input node and an output node provides 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. The voltage level at the output node corresponds to the voltage drop across the output current source transistor and the output gain transistor. | 03-10-2016 |
20160077541 | METHOD AND CIRCUIT FOR LOW POWER VOLTAGE REFERENCE AND BIAS CURRENT GENERATOR - Circuits for generating a PTAT voltage as a base-emitter voltage difference between a pair of bipolar transistors. The circuits may form unit cells in a cascading voltage reference circuit that increases the PTAT voltage with each subsequent stage. The bipolar transistors are controlled using a biasing arrangement that includes an MOS transistor connected to a current mirror that provides the base current for the bipolar transistors. A voltage reference is formed by combining a PTAT voltage and a CTAT voltage at the last stage. The voltage reference may be obtained from the voltage at an emitter of one of the bipolar transistors in the last stage. | 03-17-2016 |
20160124454 | LOW QUIESCENT CURRENT VOLTAGE REGULATOR WITH HIGH LOAD-CURRENT CAPABILITY - Embodiments of voltage regulators and methods for operating a voltage regulator are described. In one embodiment, a voltage regulator includes a set of current mirror circuits configured to convert an input voltage into an output voltage and a voltage buffer circuit configured to buffer a reference voltage for the set of current mirror circuits. The set of current mirror circuits form a positive feedback loop. Other embodiments are also described. | 05-05-2016 |
20160124455 | HIGH SPEED TRACKING DUAL DIRECTION CURRENT SENSE SYSTEM - A tracking current sense system is described that includes a current source and a current control device. The current source alternatively and substantially replicates a first current flowing through a first switch and a second current flowing through a second switch. The current control device configures the current source to alternate between replicating the first current and the second current. | 05-05-2016 |
20160147246 | Fast Bias Current Startup with Feedback - A current mirror circuit comprising an input driver connected to a plurality of output driver circuits through a current mirror network. The current mirror network is separated into two parts, wherein the first part comprises the input driver circuit and the second part comprises capacitive loads including a filter capacitor. A switch separates the two parts where an amplifier senses the first part and controls the second part to track the first part when the current mirror circuit is activated. The low source resistance of the output of the amplifier facilitates a fast charging of the capacitance of the second part of the current mirror network dramatically improving signal delay and transition time. | 05-26-2016 |
20160147247 | LOW VOLTAGE, HIGHLY ACCURATE CURRENT MIRROR - Certain aspects of the present disclosure generally relate to a low voltage, accurate current mirror, which may be used for distributed sensing of a remote current in an integrated circuit (IC). One example current mirror typically includes a first pair of transistors, a second pair of transistors in cascode with the first pair of transistors, a switching network coupled to the second pair of transistors, and a third pair of transistors coupled to the switching network. An input node between the first and second pairs of transistors may be configured to receive an input current for the current mirror, and an output node at the first pair of transistors may be configured to sink an output current for the current mirror, proportional to the input current. This current mirror architecture offers a hybrid low-voltage/high-voltage solution, tolerates low input voltages, provides high output impedance, and offers low area and power consumption. | 05-26-2016 |
20160154418 | POWER SUPPLY WITH A SWITCH CONVERTER | 06-02-2016 |