Abstract: An electronic circuit includes a switched-mode power supply powering a first load via a first linear voltage regulator. The first regulator includes a transistor. The substrate and the gate of the transistor are capable of being coupled to a node of application of a power supply voltage. A method of operating the circuit is also disclosed.

Abstract: A system includes: a reference buffer coupled to an input supply voltage; an analog-to-digital converter (ADC) coupled to an output of the reference buffer; and an output capacitor coupled between the output of the reference buffer and a ground node. The reference buffer includes: an integrator; an internal capacitor coupled between an output of the integrator and the ground node; a first gain stage with an input coupled to the output of the reference buffer; and a second gain stage with an input coupled to the output of the integrator. The output of the first gain stage is combined with the output of the integrator using a combine circuit.

Abstract: A switching power converter circuit comprises an inductor arranged to receive input energy from an input circuit node; a switch circuit coupled to the inductor; a load current sensing circuit element coupled to a regulated circuit node and an output circuit node; a compensation circuit coupled to a compensation circuit node; a control circuit coupled to the compensation circuit node and the switch circuit, the control circuit configured to modulate activation of the switch circuit to regulate a voltage at the regulated circuit node; and a feedforward circuit coupled to the load current sensing circuit element and the compensation circuit, and configured to adjust modulation of the switch circuit according to sensed load current.

Abstract: A control device includes a first switch, a second switch, a switching circuit, a first circuit and a second circuit. The control device is selectively switched to a first mode or a second mode corresponding to an operating current and an operating state of a predetermined circuit. During the first mode, an output signal of the first circuit is transmitted to a control end of the first switch through the switching circuit, and the first circuit and the first switch form a low drop-out regulator. During the second mode, a plurality of driving signals of the second circuit are transmitted to the control end of the first switch and a control end of the second switch through the switching circuit, and the first switch, the second switch and an impedance circuit form a switching voltage converter.

Abstract: According to one embodiment of this disclosure, an apparatus is disclosed. The apparatus includes a voltage regulator configured to produce a regulated voltage, a plurality of current circuits coupled in parallel between an output node and a power node, each of the plurality of current circuits including first and second transistors coupled in series, the first transistor of each of the plurality of current circuits being biased with the regulated voltage, and a control circuit configured to activate the second transistor of selected one or ones of the plurality of current circuits responsive, at least in part, to a voltage at the output node.

Abstract: An isolated switching power converter communication channel is provided that comprises a pair of capacitors. A transmitter on a first side of a transformer for the converter transmits a transmitter signal over a first one of the capacitors. The transmitter also transmits a complement of the transmitter signal over a second one of the capacitors. A receiver on a second side of the transformer recovers a signal responsive to a high-pass-filtered difference of the received signals from the pair of capacitors.

Abstract: Numerous embodiments are disclosed for a high voltage generation algorithm and system for generating high voltages necessary for a particular programming operation in analog neural memory used in a deep learning artificial neural network. Different calibration algorithms and systems are also disclosed. Compensation measures are utilized to compensate for changes in voltage or current as the number of cells being programmed changes.

Abstract: A method for parasitic-aware capacitor sizing and layout generation is proposed, which is executed by a computer, the method comprising using the computer to perform the following: creating a capacitor sizing and parasitic matching sequence to represent a unit capacitor size, routing topology and routing patterns of a plural of nets in a capacitor network. Next, a shielding assignment is performed to create a number of shielding portions of each net in the plural of nets. Then, a fitness evaluation of configurations of the capacitor sizing and parasitic matching sequence is performed. A shielding net routing is performed to compensate unmatched parasitic capacitance of the configurations of the capacitor sizing and parasitic matching sequence.

Abstract: A compensation circuit may include a reference current generating circuit including a first transistor of a first width configured to transfer a first current. The reference generating circuit may output a reference current based on the first current. The compensation circuit may include a compensation current generating circuit including a second transistor of a second width configured to transfer a second current. The second transistor may be selected from among a first group of transistors based on a code. The transistors of the first group may have widths proportional to the first width. The compensation current generating circuit may output a compensation current having a magnitude selected proportionally to a magnitude of the reference current based on the second current. The compensation circuit may include a current mirror circuit configured to output a compensation voltage having a magnitude based on a magnitude of the second current and the second width.

Abstract: A real-time slope control apparatus includes power-train transistors coupled between a power terminal and an output node and turned on in response to an error signal, a voltage regulator, a comparator configured to compare whether the feedback voltage and a sub-reference voltage match each other, pull-up transistors coupled between the power terminal and the output node and sequentially turned on in response to first control signals corresponding to a comparison result value of the comparator, and pull-down transistors coupled between the output node and the ground terminal and sequentially turned on in response to second control signals corresponding to the comparison result value of the comparator.

Abstract: A power control integrated circuit (IC) chip can include a direct current (DC)-DC converter that outputs a switching voltage in response to a switching output enable signal. The power control IC chip can also include an inductor detect circuit that detects whether an inductor is conductively coupled to the DC-DC converter and a powered circuit component in response to an inductor detect signal. The power control IC chip can further include control logic that (i) controls the inductor detect signal based on an enable DC-DC signal and (ii) controls the switching output enable signal provided to the DC-DC converter and a linear output disable signal provided to a linear regulator based on a signal from the inductor detect circuit indicating whether the inductor is conductively coupled to the DC-DC converter and the powered circuit component.

Abstract: Voltage regulators and related methods are described. The voltage regulators described in the application may include an operational amplifier, an output transistor, and a signal buffer connected between the operational amplifier and the output transistor. In some embodiments, these voltage regulators are used in connection with memory units. A voltage regulator may be arranged such that the signal amplifier clamps the voltage at the gate of the output transistor to the output voltage when the memory unit is in an idle mode. In this way, when the memory is accessed, the amplitude and duration of output voltage overshoots can be limited, relative to some voltage regulators.

Abstract: A voltage regulator is equipped with the first and the second source-grounded amplifier circuits connected to an output terminal of a differential amplifier circuit; a phase compensation circuit having a resistor part and a capacitor part, and connected between an output terminal of the first source-grounded amplifier circuit and an output terminal of the second source-grounded amplifier circuit; and an output transistor connected to the output terminal of the second source-grounded amplifier circuit. At least one of the resistor part and the capacitor part of the phase compensation circuit has a filter.

Abstract: Certain aspects of the present disclosure relate to methods and apparatus for wireless communication. In certain aspects, the apparatus generally includes a first interface configured to obtain, from a baseband module, a multiplexed signal comprising a control signal, a second interface configured to obtain a power signal, a radio frequency (RF) module, a regulator coupled to the second interface and configured to receive the power signal, and a circuit configured to provide the control signal to the regulator. In certain aspects, the regulator, in response to the control signal, may be configured to generate a supply voltage signal by regulating the power signal and provide the supply voltage signal to the RF module.

Abstract: The disclosure provides an LDO voltage regulator circuit and a related method. The circuit includes an error amplifier having a localized common-mode feedback circuit, receiving a reference voltage, a feedback voltage, and an input voltage, and generating an amplified error voltage; a pass element having a power transistor, receiving the amplified error voltage, and generating an output voltage; a feedback circuit receiving the output voltage and having a voltage divider which scales down the output voltage; a first compensation element having a first terminal which connects to an output of the input differential transistor pair and a second terminal which receives the output voltage; and a second compensation element having a third terminal which receives the output voltage and connects to the second terminal and a fourth terminal which connects to an input of a first transistor pair of the localized common-mode feedback circuit.

Abstract: A low-dropout regulator comprises a first switching transistor, a comparator, and a Miller capacitor. The first terminal of the first switching transistor is connected to a load, and the second terminal of the first switching transistor is connected to a power supply voltage. The first input terminal of the comparator is connected to a reference voltage, the second input terminal of the comparator is connected to the first terminal of the first switching transistor, and the output terminal of the comparator is connected to the control terminal of the first switching transistor. The first terminal of the Miller capacitor is connected to the control terminal of the first switching transistor, and the second terminal of the Miller capacitor is connected to the first terminal of the first switching transistor and the load.

Abstract: Disclosed is a power control method for a radio frequency power amplifier, comprising the following steps: S1. reading a power source voltage signal and a power control signal and generating an amplified signal having a linear relationship with the power control signal; S2. according to the amplified signal and saturation information, generating one or more controlled currents, merging each controlled current, and converting the merged total current into voltage; S3. Conducting linear voltage regulation on the converted voltage and generating a base control voltage of the radio frequency power amplifier. The present invention dynamically monitors the saturation information of a pass element to change the base voltage of the radio frequency power amplifier, thus improving additional power efficiency of the radio frequency power amplifier at multiple power level and over a large power source voltage range, and improving the properties of the radio frequency switch thereof.

Abstract: There is provided a DC-DC converter which is safe and secure, but yet with low power consumption. The DC-DC converter is configured such that an overcurrent protection circuit is operated intermittently only for a predetermined period of time based on a signal output from an output control circuit to turn on a switching element.

Abstract: A power supply is disclosed. The power supply includes a first switch and a second switch. The gate of the first switch is coupled to the gate of the second switch. The power supply further includes a cutoff switch coupled between the first switch and an input voltage port. A comparator is included for comparing a voltage at a feedback port with a fixed reference voltage. The comparator opens the cutoff switch when the voltage at the feedback port is lower than the fixed reference voltage.

Abstract: A circuit comprises: a pass transistor; a first transistor comprising a gate coupled to the gate of the pass transistor, a source coupled to the source of the pass transistor, and a drain; a second transistor comprising a gate coupled to the gate of the pass transistor, a source coupled to the source of the pass transistor, and a drain; a first current mirror coupled to the drain of the first transistor; a second current mirror coupled to the drain of the second transistor, and coupled to the first current mirror; a feedback voltage circuit coupled to the drain of the pass transistor; an error amplifier comprising a first input port coupled to the feedback voltage circuit, and an output port coupled to the gate of the pass transistor; and a capacitor coupled to the second current mirror and to the first input port of the error amplifier.

Abstract: Devices and methods to design voltage regulators requiring lower power consumption, wide output current and input voltage range, low dropout, and small footprint. The disclosed methods and devices provide solutions to stabilize such regulators in the presence of widely varying loads by tracking a pole of the transfer function, the pole of the transfer function corresponding to a combination of the load capacitance and the load resistance.

Abstract: A low dropout voltage regulator incorporates an N-channel MOS pass transistor, a main error amplifier, a first buffer circuit, an auxiliary error amplifier, a second buffer circuit, and a decision circuit. The auxiliary error amplifier consumes less bias current. In one embodiment, the decision circuit compares the portion of the output voltage with a bias voltage to control the gate of the N-channel MOS pass transistor, wherein the value of the bias voltage is less than the value of the reference voltage.

Abstract: In some examples, a shunt regulator includes a plurality of selection pins configured to receive a digital signal. The shunt regulator also includes an internal reference voltage selection circuit coupled to the plurality of selection pins, the internal reference voltage selection circuit configured to select a first internal reference voltage of the shunt regulator based on the digital signal. The shunt regulator further includes a soft ramp control circuit coupled to the internal reference voltage selection circuit and to a soft ramp control pin that is configured to carry a second internal reference voltage, the soft ramp control circuit configured to compare the first and the second internal reference voltages to generate a soft ramp control output signal.

Abstract: Compensation circuits, compensated voltage regulators, and methods are provided for stabilizing voltage regulators, or other circuits that use operational amplifiers, over a wide range of output current. The described techniques provide a zero whose frequency varies linearly with an output current, and which can be used to track and compensate for a pole whose frequency similarly varies with the output current. The variable-frequency zero is created using a compensation capacitor placed in series with a variable resistance, wherein the resistance is configured to vary linearly with the output current. A pole-tracking zero generated in this way may be used to overcome difficulties encountered when the gain of a system includes a pole whose frequency varies with output current, and serves to improve the phase margin of amplifier circuitry, including that used within voltage regulators, and/or serves to ensure stability over a wide range of output current.

Abstract: A voltage regulator has a slow loop for providing a regulated DC current and a fast loop for providing a transient current. Feedback information is used to monitor the output voltage and control the current used to generate the output voltage. The voltage regulator does not need a capacitor to create transient current.

Abstract: An electronic device includes a first circuit having a first ground that receives first and second control signals. A third control signal is produced by a second circuit. The second circuit uses a second ground, and the first ground floats with respect to the second ground. The first circuit determines a value corresponding to a value of a third control signal using a difference between a value of the first control signal and a value of the second control signal, the value of a third control signal being a value relative to the second ground. The first circuit controls a value of an output signal of the first circuit according to the value corresponding to the value of a third control signal.

Abstract: A voltage regulator power reporting offset system includes a monitored power reporting subsystem that determines a monitored power level, offsets the monitored power level using voltage regulator operation offset information to provide a first offset monitored power level, and reports the first offset monitored power level to voltage regulator operation components. A processor power reporting component receives the report of the first offset monitored power level from the monitored power reporting subsystem. A processor power reporting offset subsystem receives the report of the first offset monitored power level from the processor power reporting component, offsets the first offset monitored power level using the processor operation offset information to provide a second offset monitored power level that is different than the first offset monitored power level, and reports the second offset monitored power level to a processing system.

Abstract: A voltage regulator may be provided that includes a first circuit to receive at least one feedback signal from a buck converter and to provide at least one driving signal to the buck converter to provide an output voltage based on the at least one feedback signal, and a second circuit to control a super-capacitor to provide the output voltage when the first circuit is not using the buck converter to provide the output voltage.

Abstract: A voltage regulator which provides an output current at an output voltage at an output node of the voltage regulator, based on an input voltage at an input node of the voltage regulator is described. The voltage regulator has an output amplification stage for deriving the output current at the output node from the input voltage at the input node in dependence of a drive voltage. Furthermore, the voltage regulator has a differential amplification stage to determine the drive voltage in dependence of the output voltage and in dependence of a reference voltage. In addition, the voltage regulator has an adaption unit to determine a capacitance indication of a capacitor value of an output capacitor coupled to the output node of the voltage regulator. The adaption unit also adapts the differential amplification stage in dependence of the capacitance indication.

Abstract: A control circuit provides a signal to a control terminal of the transistor to control the conductivity of the transistor. The control circuit includes a voltage-to-current converter that provides an indication of the control terminal-to-current terminal voltage of a transistor. The control circuit includes control circuitry that uses the indication from the voltage-to-current converter in controlling the current applied to the control terminal.

Abstract: In an example, an apparatus includes: a pass device coupled between a supply voltage node and a load circuit and to provide a regulated voltage to the load circuit in response to a control signal received at a control terminal of the pass device; a first amplifier to compare a reference voltage to the regulated voltage and to output a comparison signal at a comparison node in response to the comparison; a second amplifier having an input device having a control terminal coupled to the comparison node to receive the comparison signal and to output the control signal to the pass device based at least in part in response to the comparison signal; and a feedback circuit to provide a feedback signal to the first amplifier based at least in part on a load current of the load circuit.

Abstract: Disclosed is a low dropout (LDO) voltage regulator that includes a differential amplifier configured to amplify a differential between a reference voltage and a regulated output voltage, a pass transistor coupled to the differential amplifier and driven by an output of the differential amplifier, a compensation capacitor coupled to an output node of the differential amplifier, and an auxiliary amplifier, wherein an output node of the auxiliary amplifier is coupled to the compensation capacitor, and wherein an input node of the auxiliary amplifier is coupled to the pass transistor.

Abstract: An output circuit at the output of an LDO regulator has two FETs (Field-Effect Transistors), a current source and a capacitor. The first FET is connected to the LDO output and a second voltage supply. The second FET is connected in series with the current source between the LDO output and the second voltage supply. The second FET is connected to the first FET in such a matter that a bias voltage is supplied to the first FET so that in static conditions the first FET draws predetermined amounts of current from the LDO output and to divert the predetermined amounts of current to the LDO output or to draw additional amounts of current from the LDO output to compensate for transient currents on the LDO output and to reduce variations in the output voltage of the LDO regulator.

Abstract: A power supply system includes a power source; a load device configured to receive power from the power source; and a power interface device coupled to the power source and the load device and configured to change a first voltage provided by the power source to a second voltage for operating the load device. The power interface device include a main switching converter configured to operate at a first switching frequency and source low frequency current to the load device and an auxiliary switching converter coupled in parallel with the main switching converter and configured to operate at a second and different switching frequency and source fast transient high frequency current to the load device.

Abstract: The present invention relates to a linear regulator with real-time frequency compensation function, which belongs to the technical field of analog integrated circuits. The part of frequency compensation of the present invention includes the dual-frequency compensation networks and compensation transfer switcher, and the pulse delay circuit. The dual-frequency compensation networks and compensation transfer switcher provide the corresponding frequency compensation for linear regulator under two different capacitive loads. The pulse delay circuit generates a set of signals which have a delay related to the switch-pulse signals to control the access of the compensation transfer switcher and capacitive load.

Abstract: Provided is a voltage regulator having satisfactory transient response characteristics. The voltage regulator includes: a first amplifier for detecting that undershoot occurs in an output voltage; a second amplifier for detecting that overshoot occurs in the output voltage; a first constant current circuit for increasing a bias current of an error amplifier circuit by a first amount for a first time period in response to a signal determined based on one of an output signal of the first amplifier and an output signal of the second amplifier; a second constant current circuit for increasing the bias current of the error amplifier circuit by a second amount larger than the first amount for a second time period shorter than the first time period in response to a signal determined based on the output signal of the first amplifier; and a first switch circuit for pulling up a gate of an output transistor in response to a signal determined based on the output signal of the second amplifier.

Abstract: A voltage regulator which provides an output current at an output voltage at an output node, based on an input voltage at an input node is described. The voltage regulator has an output amplification stage comprising a pass transistor for deriving the output current at the output node from the input voltage at the input node; and comprising a driver stage to set a gate voltage at a gate of the pass transistor based on a drive voltage. A gain of the output amplification stage is adjustable. Furthermore, the voltage regulator comprises a differential amplification unit to determine the drive voltage in dependence of the output voltage and in dependence of a reference voltage. In addition, the voltage regulator comprises a gain control circuit to adjust the gain of the output amplification stage in dependence of the output current.

Abstract: A reference circuit may include a bandgap reference stage, a filter stage, and a buffer stage. The reference stage may be configured to generate a reference voltage or current. The filter stage may be coupled to the reference stage and may be configured to receive the reference voltage or current, filter noise from the reference voltage or current, receive a buffer output voltage or current, and filter noise from the buffer output voltage or current. The buffer stage may be coupled to the filter stage and may be configured to isolate the reference stage and the filter stage from a loading effect of a load circuit and generate a reference signal based on the reference voltage or current to drive the load circuit.

Abstract: A power interface device includes a main switching converter and an auxiliary switching converter. The main switching converter is coupled to an input terminal and an output terminal and configured to operate at a first switching frequency to source a low frequency current from the input terminal to the output terminal. The auxiliary switching converter is coupled to the input terminal and the output terminal in parallel with the main switching converter and configured to operate at a second and higher switching frequency than the first switching frequency to source a fast transient high frequency current from the input terminal to the output terminal.

Abstract: In one example, a circuit includes a pass module, a first sensing module, a second sensing module, a decision module, and a control module. The pass module is configured to modify, based on a control signal, a resistance of a channel that electrically connects an input voltage and a load. The first sensing module is configured to generate a first sensed current. The second sensing module is configured to generate a second sensed current. The decision module is configured to generate a first decision current, generate a second decision current, and generate a composite sensed current based on a summation of the first decision current, the second decision current, the first sensed current, and the second sensed current. The control module is configured to generate the control signal based on the composite sensed current.

Abstract: An output circuit (10) according to the present invention includes a first output terminal (VO) and a second output terminal (SGND); an output transistor (MP1) connected between a first fixed-potential node (VCC) and the first output terminal; an output load (15) connected between the first output terminal and the second output terminal; a control circuit (13) that controls the output transistor so that a monitor voltage (VS) based on a voltage between the first output terminal and the second output terminal matches an input voltage (VI); a constant voltage source (16) whose one end is connected to the second terminal and whose other end is connected to a second fixed-potential node (GND); and a circuit (R4) that forms a current path between the first output terminal and the second fixed-potential node. Accordingly, in the output circuit, stability of a negative feedback loop can be enhanced, and linearity of an output voltage with respect to an input voltage can be enhanced.

Abstract: A low-dropout regulator with super transconductance structure relates to the field of power management technology. The super-transconductance structure refers to the circuit structure in which the voltage signal is converted into a current signal and amplified with a high magnification. The error amplifier EA in the present invention uses the super transconductance structure. The differential input pair of the error amplifier EA samples the difference between the feedback voltage VFB and the dynamic reference voltage VREF1. The difference is converted into a small signal current, which goes through a first-stage of current mirror to be amplified by K1, and through a second-stage of current mirror to be amplified by K2. The amplified signal is used to regulate the gate of the adjustment transistor MP. The error amplifier EA with the super transconductance structure is used to expand the bandwidth of the error amplifier EA.

Abstract: A control circuit for an interleaved switching power supply having a plurality of parallel coupled power stage circuits, can include: a feedback circuit that receives an output voltage of the interleaved switching power supply, and generates an output voltage feedback signal; a ripple generator that receives a plurality of switching control signals, and generates an AC ripple signal having a frequency that is N times a switching frequency; an adder circuit that adds the output voltage feedback signal with the AC ripple signal, and generates a superposition signal; a comparison circuit that receives the superposition signal and a reference voltage, and generates a comparison signal; and a frequency divider circuit that divides the comparison signal into a plurality of turn on control signals configured to control turn on of a plurality of main power switches in the plurality of power stage circuits.

Abstract: A voltage droop reduction circuit generally including a loop coupled to an output of a voltage regulator is provided. The loop includes a first current amplifier. The voltage droop reduction circuit may also include a first capacitor coupled between the output of the voltage regulator and an input of the first current amplifier.

Abstract: A dual function solid state power converter operable from a three phase AC input current simultaneously provides; an AC or DC output current on an aircraft power cable to provide ground power to a parked aircraft, and a low voltage DC current on a battery charging power cable to charge batteries in nearby service vehicles. The power converter includes an AC to DC converter which converts the current on an internal DC bus, a DC to AC converter which converts the DC bus current to an AC current at a higher voltage and frequency, or a DC to DC converter which converts the DC bus current to a lower voltage DC, for supplying ground power to a parked aircraft, and a DC to DC converter for converting the DC bus current to a lower voltage battery charging current on the battery charging cable.

Abstract: A linear regulator is presented. It comprises a first amplifier stage, one of the inputs being coupled with the output of the linear regulator. It has an intermediate amplifier stage. The input of the intermediate amplifier stage is coupled to the output of the first amplifier stage. It has a driver stage having a pass device driven by the output of the driver stage. The output of the pass device provides the output of the linear regulator. The regulator has a voltage-to-current feedback circuit coupled with the driver stage and the output of the first amplifier stage for regulating the output resistance of the first amplifier stage depending on load conditions of the linear regulator. The voltage-to-current feedback circuit has a transistor and a current limitation circuit to limit the regulation of the output resistance of the first amplifier stage to low load conditions of the linear regulator.

Abstract: The present disclosure provides a low dropout linear voltage regulator, including: an amplifier, configured to have a first input end receiving a reference voltage, a second input end configured to receive a feedback voltage, and an output end connected to a first node; an output transistor, having a control end connected to the first node, a first end connected to a first power source potential, and a second end connected to a second node and configured to provide an output voltage; a feedback circuit, connected to the second node and configured to provide the feedback voltage according to the output voltage; and a compensation circuit, comprising at least one of a first compensation amplifier, a second compensation amplifier and a first variable current source. The compensation circuit detects and suppresses a voltage transient generated when a load switching from light to heavy occurs at the second node.

Abstract: An information collection circuit includes a control circuit, which collects information of a measurement subject from a detection circuit, and a rectification circuit, which rectifies electromotive force. A first switch, coupled between the rectification circuit and the control circuit, becomes conductive based on DC voltage generated by the rectification circuit. A second switch, coupled between the control circuit and a battery, becomes conductive based on a control signal provided from the control circuit. The second switch is non-conductive when the control circuit is inactive. The control circuit is activated by a first power voltage supplied via the first switch to control the second switch to become conductive, and is operated based on a second power voltage supplied from the battery via the conductive second switch.

Abstract: A gray-scale voltage generating circuit includes a ladder resistor circuit and a constant current source. The ladder resistor circuit includes a plurality of resistors connected in series to one another, and is configured to output a plurality of gray-scale voltages with different voltage values from ends of the respective resistors. The constant current source is configured to be connected in series to the ladder resistor circuit.

Abstract: A voltage control device includes an output module and a control module. The output module provides an output current at an output terminal thereof based on a control voltage. The control module includes a comparing circuit, a capacitor, a charging circuit and a discharging circuit. The comparing circuit compares a to-be-compared voltage, which is associated at least with a to-be-controlled voltage at the output terminal of the output module, with a predetermined reference voltage to generate a comparison signal. The capacitor provides the control voltage. The charging circuit is operable to charge the capacitor based on the comparison signal. The discharging circuit is operable to discharge the capacitor based on the comparison signal.