Disclosed is a bandgap reference circuit, which includes a first current generator that generates a first current proportional to a temperature, a second current generator that outputs a second current obtained by mirroring the first current to a first node at which a reference voltage is formed, a first resistor that is connected with the first node and is supplied with the second current, and a first bipolar junction transistor (BJT) that includes an emitter node connected with the first resistor, a base node supplied with a first power, and a collector node supplied with a second power different from the first power.

A linear voltage regulator includes a transistor, an error amplifier, a feedback circuit and a compensation circuit. The transistor has a first terminal for receiving an input voltage, a second terminal for providing an output voltage, and a control terminal. The error amplifier has a first input terminal, a second input terminal and an output terminal, wherein the first input terminal receives a reference voltage, and the output terminal is coupled to the control terminal of the transistor. The feedback circuit receives the output voltage and generates a feedback voltage lower than the output voltage. The compensation circuit is configured to receive the feedback voltage and generate a compensation voltage at the second input terminal of the error amplifier. The compensation circuit includes a compensation capacitor for introducing a zero point into an open-loop transfer function of the linear voltage regulator to improve system stability.

A power regulator is applied to regulate a work frequency of a central processing unit and the power regulator comprises a power resister, a voltage amplifier and an analog-to-digital converter. The power resister is coupled to a load to generate a first voltage. The voltage amplifier is coupled to the power resister to output a second voltage. The analog-to-digital converter is coupled to the voltage amplifier, converts the second voltage into a control signal and transmits the control signal to the central processing unit. The control signal is switched between a first level and a second level according to a value of the second voltage.

A constant voltage circuit amplifies an error between a reference voltage and an output voltage by an operational amplifier, and controls a load current based on the amplified voltage so that the output voltage becomes a constant voltage. The constant voltage circuit includes voltage detector means that detects only AC components of the output voltage limited to a predetermined band and outputs a detected voltage; voltage amplifier means that amplifies AC components of the detected voltage and outputs an amplified voltage; judgment means that outputs a judgment signal indicating whether or not the amplified voltage equal to or larger than a predetermined threshold; and controller means configured to increase a current value of the constant current source included in the operational amplifier, based on the judgment signal, thereby temporarily increasing a current consumption of the operational amplifier.

A reference voltage circuit is disclosed. In the reference voltage circuit, a comparator compares a reference voltage and a voltage of a capacitor, so as to output a comparison signal; a controller checks conditions of the reference voltage and the leakage current based on the comparison signal; when a voltage of the capacitor is reduced too quickly, the controller adjusts a switching frequency of a switch device to effectively maintain the voltage of the capacitor.

An analog circuit arrangement (1) to variably set a voltage U.sub.out, within defined voltage limits, has a non-inverting adder (10) with a positive input (11). A voltage divider (20), with at least a first stage (21) and a second stage (22), is connected to the positive input (11) of the adder (10). At least one stage has a parallel circuit of n resistors (R1, R2, . . . , Rn) that are each connected in series in a conduction path (L1, L2, . . . , Ln) to an overcurrent protection device (F1, F2, . . . , Fn). At least one device (30) actively changes one or more of the overcurrent protection devices (F1, F2, . . . , Fn) into a state that interrupts the respective affected conduction path (L1, L2, . . . , Ln).

An electronic system comprising a voltage-to-current converter and a proportional-to-absolute-temperature (PTAT) circuit is disclosed. The voltage-to-current converter is configured to receive one of a control voltage, a supply voltage, a scaled-down version of the control voltage, and a scaled-down version of the supply voltage, and generate a set of currents. The PTAT circuit is coupled with the voltage-to-current converter such that each current of the set of currents is one of sourced to the PTAT circuit and sank from the PTAT circuit. Further, the PTAT circuit is configured to receive at least one of the supply voltage and the control voltage, and generate a set of reference voltages. The control voltage is generated based on the set of reference voltages and the supply voltage.

A constant voltage device include a diode; a switch including one terminal connected to a ground potential and another terminal connected both to an anode terminal of the diode and to a drain of a PMOS transistor having a source applied with a power source voltage; a voltage generation circuit configured to generate a voltage of a predetermined magnitude; and a differential amplifier that includes a non-inverting input terminal to which both a cathode terminal of the diode and an output terminal of the voltage generation circuit are connected, and that is configured to change a supply route of a reference voltage applied to the non-inverting input terminal according to a state of the switch. The voltage generation circuit is configured to employ an output voltage based on the reference voltage and amplified by the differential amplifier to generate the reference voltage.

An electronic device including: a reference voltage generator circuit to generate a reference voltage based on a first and second voltage, the reference voltage generator circuit including: a first current source to supply a first current to each of a first and second node; an amplifier to amplify a difference between the first voltage of the first node and the second voltage of the second node and to output a difference voltage corresponding to the amplified difference; a first bipolar junction transistor (BJT) connected to the first node; a first resistor connected to the second node; a second BJT connected between the first resistor and ground; a second resistor connected between the second node and ground; and a first transistor to be supplied with a second current from the first current source; and an adaptive cascode circuit to generate a bias voltage applied to a gate of the first transistor.

A load coupled to a linear voltage regulator may create a load transient so that an output of the voltage regulator is temporarily raised to an elevated level above a regulated level. Without compensation, the linear voltage regulator may respond by turning a pass transistor completely OFF thereby losing regulation and allowing a compensation capacitor to become charged in a polarization opposite to one required for regulation. If a subsequent load transient (i.e., back-to-back load transient) is generated while the linear voltage regulator is in this condition, a large spike in the output may occur as the voltage regulator recharges the pass transistor turns back ON and as the compensation capacitor recharges. Disclosed herein is a linear voltage regulator with transient compensation circuitry to prevent the scenario described above and reduce the spike in the output.