Abstract: Described embodiments include a circuit for reducing output voltage noise in a voltage regulator includes an amplifier having first and second amplifier inputs, a compensation terminal and an amplifier output. The first amplifier input is coupled to a reference voltage terminal, and the compensation terminal coupled to an output terminal. A buffer amplifier has a buffer input and a buffer output, and the buffer input is coupled to the amplifier output. A first transistor is coupled between a supply voltage terminal and the output terminal, and has a first control terminal that is coupled to the buffer output. A boost current injection circuit has a boost input and a boost output, and the boost input is coupled to the supply voltage terminal. A second transistor is coupled between the boost output and the compensation terminal, and has a second control terminal.

Abstract: The invention discloses a low power consumption and high precision resistance-free CMOS reference voltage source circuit, which includes a, a positive temperature coefficient voltage generation circuit and a starting circuit. The self-bias current source circuit uses two NMOS tubes with different threshold voltages in the subthreshold region to form a stack structure, which generates the bias current and negative temperature coefficient voltage on the order of nanoampere. The positive temperature coefficient voltage generation circuit uses PMOS differential to generate positive temperature coefficient voltage for the structure and performs first-order curvature compensation for negative temperature coefficient voltage.

Abstract: A reference current source includes a reference current path, a first output current path and a second output current path. The reference current path includes a diode-connected first transistor, a diode-connected second transistor, and a first resistor that are connected in series between a first fixed potential and a second fixed potential. The first output current path includes a third transistor having a gate connected to a gate of the second transistor, forming a current mirror together with the second transistor, and a second resistor interposed between the third transistor and the first fixed potential. The second output current path includes a voltage-current conversion circuit to which a potential of a third node between the third transistor and the second resistor in the first output current path is applied and through which a reference current flows.

Abstract: A bandgap reference circuit includes a bandgap reference core circuit that includes a first bipolar transistor having a first emitter current density and a first base-emitter voltage, a second bipolar transistor having a second emitter current density that is smaller than the first emitter current density and having a second base-emitter voltage, a resistor that is connected to the emitter of the second bipolar transistor, and a differential amplifier circuit that is configured to control first and second emitter currents through the first and second bipolar transistors, respectively, such that a sum of the second base-emitter voltage and a voltage drop across the resistor approximates the first base-emitter voltage. The bandgap reference circuit further includes a first replica bipolar transistor that emulates an operating point of the first bipolar transistor and a second replica bipolar transistor that emulates an operating point of the second bipolar transistor.

Abstract: A semiconductor device may include a bandgap circuit that outputs a reference voltage. The bandgap circuit may include a bandgap core circuit and a startup circuit coupled to the bandgap core circuit. The startup circuit may connect a voltage source to a node that corresponds to an output of the bandgap core circuit in response to the bandgap core circuit being initialized. The startup circuit may also disconnect the voltage source from the node in response to the output voltage being equal to or greater than a desired voltage (e.g., a threshold voltage) and one or more local voltages of the bandgap core circuit being equal to or greater than a local threshold voltage.

Abstract: A disclosed circuit arrangement detects the supply voltage level to the “device” (SoC, chip, SiP, etc.) and adjusts bias voltages to receiver and transmitter circuits of the device to levels suitable for the device in response to the supply voltage ramping-up during a power-on reset (“POR”) sequence. The circuitry holds the receiver output at a constant logic value while the supply voltage is ramping up and the POR signal is asserted. The disclosed circuitry also protects the transceiver as the voltage domain of the input signal is unknown and the voltage between any two terminals of a transistor of the transceiver cannot exceed a certain level.

Abstract: Certain aspects of the present disclosure are directed to a regulator. The regulator generally includes a source follower circuit and a low-voltage assist circuit. The low-voltage assist circuit generally includes a first transistor having a gate coupled to an output node of the source follower circuit, a voltage comparison circuit having a first input coupled to a source of the first transistor and a second input coupled to a control input node of the source follower circuit, and a second transistor having a gate coupled to an output of the voltage comparison circuit and a drain coupled to the output node of the source follower circuit.

Abstract: Systems and methods as described herein may take a variety of forms. In one example, systems and methods are provided for a circuit for powering a voltage regulator. A voltage regulator circuit has an output electrically coupled to a gate of an output driver transistor, the output driver transistor having a first terminal electrically coupled to a voltage source and a second terminal electrically coupled to a first terminal of a voltage divider, the voltage divider having an second terminal electrically coupled to ground, and the voltage divider having an output of a stepped down voltage. A power control circuitry transistor has a first terminal electrically coupled to the voltage source, the power control circuitry transistor having a second terminal electrically coupled to the gate terminal of the output driver transistor, and the power control circuitry transistor having a gate terminal electrically coupled to a status voltage signal.

Abstract: To provide a circuit used for a shift register or the like. The basic configuration includes first to fourth transistors and four wirings. The power supply potential VDD is supplied to the first wiring and the power supply potential VSS is supplied to the second wiring. A binary digital signal is supplied to each of the third wiring and the fourth wiring. An H level of the digital signal is equal to the power supply potential VDD, and an L level of the digital signal is equal to the power supply potential VSS. There are four combinations of the potentials of the third wiring and the fourth wiring. Each of the first transistor to the fourth transistor can be turned off by any combination of the potentials. That is, since there is no transistor that is constantly on, deterioration of the characteristics of the transistors can be suppressed.

Abstract: Systems and methods are provided for generating a temperature compensated reference voltage. A temperature compensation circuit may include a proportional-to-absolute temperature (PTAT) circuit, and a complementary-to-absolute temperature (CTAT) circuit, with the PTAT circuit and the CTAT circuit including at least one common metal-oxide-semiconductor field-effect transistor (MOSFET) and being configured to collectively generate a reference voltage in response to a regulated current input. The PTAT circuit may be configured to produce an increase in magnitude of the reference voltage with an increase of temperature, and the CTAT circuit may be configured to generated a decrease in magnitude of the reference voltage with the increase of temperature, wherein the increase in magnitude of the reference voltage produced by the PTAT circuit is at least partially offset by the decrease in magnitude of the reference voltage produced by the CTAT circuit.

Abstract: A wafer burn-in test circuit may be provided. The wafer burn-in test circuit may include a timing correction unit configured to generate a plurality of timing-compensated input signals by synchronizing a plurality of pulse signals generated according to a plurality of input signals with an input signal among the plurality of input signals. The wafer burn-in test circuit may include a wafer burn-in signal decoding unit configured to generate a plurality of decoding signals by decoding the plurality of timing-compensated input signals and output the plurality of decoding signals as a plurality of wafer burn-in signals by latching the plurality of decoding signals.

Abstract: A device includes a voltage regulator, an auxiliary signal generator, and a circuit cell. The voltage regulator is configured to output a write voltage. The auxiliary signal generator is configured to output an auxiliary signal. The circuit cell is configured to receive both of the write voltage and the auxiliary signal according to a first select signal and a second select signal.

Abstract: The present inventive concept is a hyuntak transistor that can prevent a thermal runaway phenomenon and a low heat high efficiency constant current circuit using an auxiliary transistor capable of a high amplification and a constant current. The circuit may be applied to drive a LED and a motor.

Abstract: Described examples include sensing circuits and reference voltage generators for providing a reference voltage to a sensing circuit. The sensing circuits may sense a state of a memory cell, which may be a PCM memory cell. The sensing circuits may include a cascode transistor. Examples of reference voltage generators may include a global reference voltage generator coupled to multiple bank reference voltage generators which may reduce an output resistance of the voltage generator routing.

Abstract: A reference voltage generating circuit comprises a pair of variable resistors connected to a pair of bipolar transistors. A differential amplifier amplifies the band gap voltage difference between the bipolar transistors and outputs a reference voltage to an output terminal. An output stage resistor is connected to the output terminal and a resistance dividing circuit. The generating circuit includes temperature compensating circuits that receive tap voltages from resistance dividing circuit and a current proportional to the temperature, then output correction currents. The generating circuit additionally includes a current mirror circuit that outputs a mirror current depending on each correction current. The reference voltage generating circuit thus corrects the temperature dependence of the reference voltage.

Abstract: An electronic switching device comprises a first bipolar junction transistor (BJT) (2a) adapted to control the flow of current between a pair of switching terminals; a charge recovery circuit coupled to the base of the first BJT (2a) and adapted to establish a supply voltage across a capacitor (5) by storing in the capacitor (5) charge carriers accumulated in the base of the first BJT (2a) during application of a base drive current, the quantity of accumulated charge carriers depending on the base drive current; and a controllable current source (4) adapted to control the base drive current, thereby controlling the supply voltage.

Abstract: An improved current mirror circuit. The current mirror circuit includes a current mirror base network, a current source transistor, and an error transistor. The current mirror base network includes a first terminal, a second terminal, and a third terminal. The first terminal is connected to the current source transistor through a first impedance element. The second terminal is connected to the error transistor. The third terminal is connected to a first bias voltage source, and the first terminal is connected to a second bias voltage source.

Abstract: A semiconductor device and a method of operating the semiconductor device. The semiconductor device includes a voltage generator configured to generate a test voltage, a graphene transistor configured to receive a gate-source voltage based on the test voltage, and a detector configured to detect whether the gate-source voltage is a Dirac voltage of the graphene transistor, and output a feedback signal applied to the voltage generator indicating whether the gate-source voltage is the Dirac voltage.

Abstract: A method includes generating a first current, wherein the first current flows through a first resistor and a first bipolar transistor. A first end of the first resistor is serially connected to an emitter-collector path of the first bipolar transistor, and a second end of the resistor is connected to an input of an operational amplifier. A second current is generated to flow through a second resistor that is connected to the input of the operational amplifier. An emitter of a second bipolar transistor is connected to a base of the first bipolar transistor, wherein a base and a collector of the second bipolar transistor are connected to VSS. The first and the second currents are added to generate a third current, which is mirrored to generate a fourth current proportional to the third current. The fourth current is conducted through a third resistor to generate an output reference voltage.

Abstract: A charging circuit includes a first current mirror including a first branch circuit, a second branch circuit and a third branch circuit for generating a first conduction current, a second conduction current and a third conduction current according to the input voltage, a second current mirror including a fourth branch circuit coupled to the first branch circuit and including a first channel width, and a fifth branch circuit coupled to the second branch circuit and including a second channel width, wherein a load circuit is coupled between the first current mirror and the second current mirror, and the first current mirror as well as the second current mirror correspondingly adjust values of the first conduction current, the second conduction current and the third conduction current according to the first channel width as well as the second channel width, so as to process a charging operation of the load circuit.

Abstract: A method and an apparatus for controlling voltage level and clock signal frequency supplied to a system.

Abstract: Embodiments of the present invention may provide an integrated circuit that may comprise a first transistor to receive an input voltage signal at its gate and generate an output voltage signal at its drain. Further, the integrated circuit may comprise a second transistor to form an active load of the first transistor, the second transistor may have its drain and gate coupled to the drain of the first transistor. In addition, the integrated circuit may comprise a third transistor to form a current mirror with the second transistor, a fourth transistor to form an active load of the third transistor, and a fifth transistor to form a current mirror with the fourth transistor. The fifth transistor may be connected to the drain of the second transistor. The integrated circuit may form an amplifier and Gm stage of a reference buffer.

Abstract: A semiconductor device, circuit, and AC and DC load switch for maintaining a small input-output differential voltage and providing a defined response. The load switch can include a pass element coupled to an input terminal and an output terminal. The pass element can include a control terminal, with the control terminal controlling a response of the pass element. The load switch can include a first loop coupled to the control terminal configured to control a voltage drop between the input terminal and the output terminal while maintaining high impedance with the pass element. The load switch can include a second loop coupled to the control terminal configured to provide a defined filter response from the input terminal. The defined response can be a low pass response, high pass response, or a band pass response. The passband and/or stopband of the response can be programmed.

Abstract: Circuit unit (CU) comprising a heterojunction bipolar transistor and a long-gate pseudomorphic high-electron-mobility transistor. Either a source (S) or a drain (D) of the long-gate pseudomorphic high-electron-mobility transistor is electrically coupled with either a collector (C) or an emitter (E) of the heterojunction bipolar transistor.

Abstract: The present invention provides a reference power supply circuit which does not require trimming and prevents occurrence of deadlock of a band gap reference circuit. An RFID tag chip related to the present invention has a reference power supply including a switch for switching between a band gap reference circuit and a Vth difference reference circuit. A reference potential in band gap reference of the band gap reference circuit and an output of the Vth difference reference circuit are compared by a comparator, and a transistor operating as a switch is controlled, thereby making the reference potential in band gap reference rise, hastening startup of the band gap reference circuit, and preventing occurrence of deadlock in the band gap reference circuit.

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

Abstract: Systems and methods are disclosed that use multiple DC-DC (direct-current-to-direct-current) regulators and configurable DC-DC regulators with respect to multi-band audio receivers in order to allow for the use of different DC-DC regulator switching clock signals for different audio broadcast bands. The systems and methods disclosed thereby help to alleviate interference problems typically caused by switching devices used in the DC-DC conversion process. The embodiments described are also applicable to switching power supplies run from alternating current (AC) power sources and to Class D amplifiers working with broadcast radios.

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: In order to realize a reference voltage circuit that operates with lower current consumption while maintaining an operation at lower voltage without causing deterioration of a power supply rejection ratio, provided is a reference voltage circuit in which a depletion transistor of an ED type reference voltage circuit is constituted of a plurality of depletion transistors connected in series, and in which a gate terminal of a cascode depletion transistor is connected to a connection point between the depletion transistors of the ED type reference voltage circuit.

Abstract: A circuit includes an operational amplifier including a first input and a second input. A first resistor has a first end coupled to the first input. A first bipolar transistor includes a first emitter coupled to a second end of the first resistor, and a first base. A second bipolar transistor includes a second emitter coupled to the second input, and a second base. A third bipolar transistor includes a third emitter coupled to the first base, a first collector, and a third base connected to the first collector. A fourth bipolar transistor includes a fourth emitter coupled to the second base, a second collector, and a fourth base connected to the second collector. A second resistor is coupled to the first input, wherein the second resistor is parallel to the first resistor and the first bipolar transistor.

Abstract: In one embodiment, a current mirror circuit includes first to fourth insulated gate field effect transistors (FETs), and a bias circuit. The gate electrodes of the first and second FETs are connected to each other. The source electrode of the third FET is connected to the drain electrode of the first FET, and the drain electrode of the third FET is connected to the gate electrodes of the first and second FETs and a current input terminal. The gate electrode of the fourth FET is connected to the gate electrode of the third FET, the source electrode of the fourth FET is connected to the drain electrode of the second FET, and the drain electrode of the fourth FET becomes a current output terminal. The bias circuit is configured to provide a bias voltage to the gate electrodes of the third and fourth FETs.

Abstract: A semiconductor integrated circuit includes an external terminal input with an external power supply voltage, a plurality of field effect transistors connected between the external terminal and an internal power supply line and a control circuit input with potentials of spots where voltage drops from output points of the output transistors are substantially the same in the internal power supply line, and controlling the plurality of field effect transistors according to the potential being input.

Abstract: An electronic device includes a cascade of a plurality of transistors. Each transistor of the cascade receives an input voltage at a first terminal of its source/drain channel and receives a sampling clock signal at a control gate. The second terminal of the source/drain path of a first transistor drives a sampling capacitor. The second terminal of the source/drain channel of each subsequent transistor is connected to a backgate of a previous transistor. The backgate of the last transistor is connected to a supply voltage level. The second terminals of the subsequent transistors may be connected to corresponding buffer capacitors. The backgate of the last transistor may be supplied with the input during sampling and the supply voltage level at other times.

Abstract: A current drive circuit allows for a reduction in chip size and prevents an output current from decreasing. The current drive circuit has an output terminal connected to a first resistor. The first resistor is connected to a second resistor and the drain of a first transistor. The gate of the first transistor is connected to the gate of a second transistor, a grounded first current source, and the source of a third transistor. A second current source and the third transistor are connected to a power supply line. The second current source is connected to the gate of the third transistor, the drain of a fourth transistor, the drain of a fifth transistor, and a second resistor. When the voltage decreases, the on resistance of the fourth transistor increases, the fifth transistor is then connected in series to the second transistor, which increases the gate voltage of the first transistor.

Abstract: A reference voltage generating circuit includes a current generating section, a voltage generating section, a voltage dividing circuit, and a synthesis section. The current generating section generates a first current having a positive temperature coefficient. The voltage generating section generates a voltage having a negative temperature coefficient. The voltage dividing circuit divides the voltage of the negative temperature coefficient, generated by the voltage generating section. The synthesis section generates a voltage which is the sum of a terminal voltage obtained on causing the first current through a resistor and a voltage obtained on dividing the voltage having the negative temperature coefficient by the voltage dividing circuit, and outputs the sum voltage generated as a reference voltage.

Abstract: A reference voltage generating circuit includes a reference voltage generating unit generating a uniform reference voltage in response to a bias voltage, a bias voltage generating unit generating the bias voltage, and a start-up circuit, after activating the bias voltage generating unit by receiving a first supply voltage, canceling a change of the first supply voltage to maintain a separation from the bias voltage generating unit. The circuit adopts a start-up circuit having a voltage distributing unit, thereby preventing a quiescent point of a bias voltage generating unit from entering a zero state and prevents a reference voltage from rising in a power-up state that an analog supply voltage rises according to a change of an external design environment such as a power, a temperature, a process parameter and the like, thereby generating a reference voltage more stably. As a result, current consumption and power consumption are minimized.

Abstract: A method for improving analog circuits performance using a circuit design using forward bias and a modified mixed-signal process is presented. A circuit consisting plurality of NMOS and PMOS transistors is defined. The body terminal of the NMOS transistors are coupled to a first voltage source and the body terminal of the PMOS transistors are coupled a second voltage source. Transistors in the circuit are selectively biased by applying the first voltage source to the body terminal of each selected NMOS transistor and applying the second voltage source to the body terminal of each selected PMOS transistor. In one embodiment, the first voltage source and the second voltage source are modifiable to provide forward and reverse bias to the body terminal of the transistors.

Abstract: A voltage regulator and a voltage regulating method thereof and a voltage generator using the voltage regulator are disclosed by the present invention. The voltage regulator of the present invention uses a first switching unit and a second switching unit to respectively provide an operational transconductance amplifier (OTA) with different closed-loop feedback paths during a first period and a second period. In this way, an auto-zeroing unit is able to exactly store an input offset voltage presented between the inverting input terminal and the non-inverting input terminal of the OTA.

Abstract: A bandgap voltage reference circuit which provides a bandgap reference voltage without requiring a resistor. The circuit comprises an amplifier having an inverting input, a non-inverting input and an output. First and second bipolar transistors are provided which operate at different current densities each coupled to a corresponding one of the inverting and non-inverting inputs of the amplifier. A load MOS transistor of a first aspect ratio is driven by the amplifier to operate in the triode region with a corresponding drain-source resistance ron. The load MOS device is operably coupled to the second bipolar transistor such that a base-emitter difference (?Vbe) resulting from the collector current density difference between the first and second bipolar transistors is developed across the drain-source resistance ron, of the load MOS device. A cascoded MOS device of a second aspect ratio is operably coupled to the load MOS device and is driven by the amplifier to operate in the triode region.

Abstract: A reference voltage circuit which is less dependent on semiconductor process variations compared to bandgap based reference voltage circuits. The circuit comprises a first amplifier having an inverting input, a non-inverting input and an output. A current biasing circuit provides first and second PTAT currents, and a CTAT current. The CTAT current is equal in value to the second PTAT at a first predetermined temperature and opposite in polarity. A first load element is coupled to the non-inverting input of the first amplifier and arranged for receiving the first PTAT current such that a PTAT voltage is developed across the first load element. A feedback load element is coupled between the inverting input and the output of the amplifier for receiving the summation of the CTAT current and the second PTAT current.

Abstract: A bandgap voltage reference circuit with an inherent curvature correction which comprises an amplifier having an inverting terminal, a non-inverting terminal and an output terminal is described. A first and second bipolar transistor operable at different current densities are provided each of the transistors being coupled to a corresponding one of the inverting and non-inverting terminals of the amplifier such that a ?Vbe is reflected across a first load element. A current biasing circuit is provided which includes a semiconductor device coupled to each of the first and second bipolar transistors and is configured for applying a non-linear bias current to the first and second bipolar transistors for biasing thereof.

Abstract: A bandgap reference circuit which is operable in low supply conditions is described. Such a circuit includes a second amplifier and a resistor at the output of a bandgap reference cell to create a constant current summing node at which PTAT and CTAT currents are summed. In modifications to the circuit it is possible to also provide a voltage reference node corresponding to the signal provided at the summing node. A further modification enables generation of a second voltage reference whose value is related to the base emitter voltage Vbe of a bipolar transistor. Further modifications provided for the generation of curvature correction within the circuit by biasing each of the first and second bipolar transistors Q1 and Q2 with currents of different forms.

Abstract: A reference voltage generating circuit is described. The circuit includes a current generating section that generates a first current having a positive temperature coefficient, a voltage generating section that generates a voltage having a negative temperature coefficient, a synthesis section that generates a voltage which is the sum of a voltage having a positive temperature coefficient and developed across both terminals of a resistor, where the voltage has a negative temperature coefficient, and a compensation current generating section that generates a second current having a positive temperature coefficient. The current corresponding to the sum of said first and second currents is caused to flow through the resistor. The synthesis section generates a voltage which is a sum of a terminal voltage of the resistor by the sum current of the first and second currents and the voltage having a negative temperature coefficient.

Abstract: A reference circuit. Included are first and second reference circuit blocks, first and second controllable current sources connected to supply current through the first and second reference circuit blocks respectively, an amplifier having non-inverting and inverting inputs responsive to the voltages developed by the first and second reference circuit blocks respectively and having an output connected to control the currents provided by the first and second current sources, and an output stage having a reference output controlled by the output of the amplifier. The reference circuit further comprises start-up circuitry, including a latch having an output indicating its state and being responsive to a signal indicative of the output from the reference output to latch from a first state into a second state when that signal passes a first threshold, and a switch that is responsive to the output of the latch to supply a control signal.

Abstract: Techniques pertaining to a circuit architecture capable of controlling a current source to a predefined precision are disclosed. According to one aspect of the present invention, an automatic trimming circuit is proposed to automatically trim a current generated from a current generator or circuit in accordance with a reference current. The automatic trimming circuit includes a comparator, an ADC and a register. The comparator that may be implemented as a subtractor finds a difference between a generated current and a reference current. The difference is then digitized to an n-bit precision. A digital representation of the difference is then kept in a register and used subsequently correct or modify the generated current to produce a precisely controlled current.

Abstract: A current mirror has an input bipolar device and an output bipolar device, a first MOSFET device to control a current in the input bipolar device, and a second MOSFET device to control a bias current to common base terminals of the input and output bipolar devices. An output stack may be coupled to the bipolar output device, and may include at least one output MOSFET device.

Abstract: A reference circuit includes: (a) a first reference circuit having a reference signal and a ?VBE loop; and (b) a modification circuit using a first voltage to change a first current in the ?VBE loop of the first reference circuit. In one embodiment, the reference circuit is a voltage reference circuit. In some embodiments, the reference circuit can include a bandgap core circuit, which adds a VBE and a multiplied ?VBE, so that the output voltage of the reference circuit is a bandgap voltage. The reference circuit also can also include a modification circuit, which uses the output voltage (i.e. the reference signal) of the bandgap core circuit to change a current in the ?VBE loop. The ?VBE loop can be the portion of the circuit involved in generating the ?VBE voltage. Other embodiments are disclosed in this application.

Abstract: A master bias current generating circuit includes a current source, a first reference leg, and a second reference leg. The first reference leg includes a first transistor having a first size parameter coupled to the current source and a first diode having a second size parameter coupled to the first transistor. The second reference leg includes a second transistor having a third size parameter less than the first size parameter coupled to the current source and a second diode having a fourth size parameter greater than the second size parameter coupled to the second transistor.

Abstract: A voltage regulator includes first and second MOS transistors and a bipolar transistor. The first MOS transistor has a first conductivity type and has a drain coupled to a first power supply voltage terminal, a gate for receiving a first bias voltage, and a source. The second MOS transistor has a second conductivity type and has a source coupled to the first power supply voltage terminal, a drain coupled to the source of the first MOS transistor, and a gate for receiving a second bias voltage. The bipolar transistor has a collector coupled to the source of the first MOS transistor, a base for receiving a third bias voltage, and an emitter for providing an output voltage. The first MOS transistor and the second MOS transistor control a voltage level at the collector of the bipolar transistor in response to a varying power supply voltage provided to the first power supply voltage terminal.

Abstract: Each of stages RS(1), RS(2), . . . of a shift register is constituted by six TFTs. A ratio of a channel width and a channel length (W/L) of each of these TFTs 1 to 6 is set in accordance with a transistor characteristic of each TFT in such a manner that the shift register normally operates for a long time even at a high temperature.