Abstract: A bias current control method for an operational amplifier is disclosed, which includes detecting a slew rate operating signal, determining signal period length of the slew rate operating signal to generate a determination signal, and generating a high bias modulation signal or a low bias modulation signal to the operational amplifier according to the determination signal and the slew rate operating signal.

Abstract: This disclosure provides systems, apparatus, and methods for switching a portion of a power amplifier on and off during different modes of operation. In one aspect, a control circuit can include separate switches to provide bias currents to different portions of a power amplifier. The control circuit can include another switch to electrically connect outputs of the separate switches in a first mode of operation (for example, a high power mode) and electrically isolate the outputs of the separate switches in a second mode of operation (for example, a low power mode). In some implementations, a circuit element, such as a field effect transistor or a diode, can turn off one of the separate switches in the second mode. Alternatively or additionally, another circuit element, such as a field effect transistor or a diode, can prevent a power amplifier portion from turning on in the second mode.

Abstract: An amplifying device which amplifies a signal, includes: an amplifier which amplifies an input signal by a power supplied from a power node; a first power source which supplies a fixed voltage to the power node; a second power source which supplies a variable voltage to the power node based on an envelope signal relating to the input signal and voltage of the power node; an active short device which reduces impedance of the power node when the first power source supplies the power to the power node and the second power source does not supply the power to the power node; a synthesizer which synthesizes the envelope signal and a cancel signal so that the second power source does not supply the power to the power node according to voltage variation of the power node by the active short device.

Abstract: A digital pre-distortion (DPD) power amplifying apparatus and a method for digitally controlling synchronization of the DPD power amplifying apparatus, which includes a power amplifier, a bias shifter and a DPD unit, are provided. The method includes acquiring a DPD path delay time at a path along which an input signal is fed back to the DPD unit; delaying an input signal incoming to the power amplifier by the DPD path delay time and acquiring synchronization by delaying a bias signal a predetermined number of times until the bias signal and the delayed input signal are synchronized with each other; and in response to synchronization between the bias signal and the delayed input signal being established, pre-distorting the input signal according to a feedback signal output from the power amplifier.

Abstract: A radio device includes an amplifier and first and second independently operable variable voltage supply inputs to the amplifier, providing a consistent output power range for the radio device across widely varying temperature conditions.

Abstract: A circuit method includes periodically increasing a tail current of a differential stage of a comparator to periodically power on the differential stage to a power-on state, and periodically decreasing the tail current of the differential stage to periodically power down the differential stage to a low-power state. The periodically increasing of the tail current and the periodically decreasing of the tail current are asynchronous operations for powering on the differential stage to the power-on state and powering down the differential stage to the low-power state. Periodically increasing the tail current and the periodically decreasing the tail current asynchronously for powering on the differential stage to the power-on state and powering down the differential stage to the low-power state provide for low noise and high speed during signal comparison.

Abstract: There is provided an amplifier circuit, comprising: an input, for receiving an input signal to be amplified; a power amplifier, for amplifying the input signal; a switched power supply, having a switching frequency, for providing at least one supply voltage to the power amplifier; and a dither block, for dithering the switching frequency of the switched power supply. The dither block is controlled based on the input signal. Another aspect of the invention involves using first and second switches, each having different capacitances and resistances, and using the first or second switch depending on the input signal or volume signal. Another aspect of the invention involves controlling a bias signal provided to one or more components in the signal path based on the input signal or volume signal.

Abstract: A wireless transceiver may include a power amplifier that uses an envelope tracker. The envelope tracker may include stacked buck switching supply modulators, each having two different supply voltages. In one embodiment, the two different supply voltages are higher and lower supply voltages, which relaxes the voltage head room on the switching regulator and allows the use of thin gate fast transistors in some embodiments.

Abstract: Amplifier circuitry (10) includes a driver amplifier (11) and an integrator amplifier (AH) producing an output signal (VAH) that controls a pass transistor (Q2) coupled to a pump capacitor (CH). Input circuitry (16) controls the direction of ramping of the output signal during a first interval to boost a supply voltage (V12) of the driver amplifier via the pump capacitor, and also controls the direction of ramping to recharge the pump capacitor following a second interval. In one embodiment, pump capacitor recharging circuitry (Q75,R76,ICCH) completes the recharging of the pump capacitor following the second interval after it has been partially recharged by the integrator amplifier.

Abstract: A method generates a reference voltage by steps including: generating a reference signal from a voltage source; generating a comparison signal of the reference signal with a voltage reference; sampling the comparison signal; adjusting a numerical value as a function of the result of the comparison and of the numerical value; and converting the current numerical value into a voltage corresponding to the reference voltage.

Abstract: An automatic gain control circuit is provided for an input signal in the form of a dc reference level and a superposed amplitude modulated ac data signal. A feedforward AGC loop has a low pass filter for deriving the level of attenuation from the attenuated dc reference level. A multiplier value (G) is based on the reciprocal of the level of attenuation (?) and this multiplier enables an output signal to be generated comprising a constant multiple (DG) of the input signal.

Abstract: A transistor resistor and an associated method are provided to improve the resistance linearity of the transistor resistor. The transistor resistor includes a transistor operating in the resistive region, where the drain and source of the transistor receive an input signal and an output signal respectively. The transistor resistor also includes a compensating circuit for generating a compensating signal according to the input signal. The compensating signal is provided to the gate of the transistor such that the voltage difference between the gate and source of the transistor approximates to a constant.

Abstract: An audio amplifier having a variably configurable housing, which may be mounted to an interior surface of a motor vehicle. The housing is formed in two complementing housing sections mutually joined by a hinge, tether, or other connector. A power supply is contained in one housing section and an audio output module is contained in the other housing section. The power supply and audio output module may be connected by flexible signal conductors to accommodate pivot of the two housing sections relative to one another. A heat sink comprising cooling fins and communications and power terminals may be disposed on the exterior of the housing sections to enable conventional connection to an associated audio system. The hinge may incorporate a fixing element which releasably holds the two housing sections at a selected degree of pivot.

Abstract: An apparatus for controlling a power amplifier configured to amplify radio frequency (RF) signal includes a detector and a controller. The detector is configured to detect a power level of the RF signal with respect to a predetermined power threshold and to generate a corresponding detection signal. The controller is configured to provide a control voltage to an output transistor of the amplifier based on the detection signal. The control voltage has a low voltage value, which is substantially the same as a value of a supply voltage, when the detection signal indicates that the power level is below the power threshold, and the control voltage has a high voltage value when the detection signal indicates that the power level is above the power threshold. The controller generates the high voltage value by boosting the supply voltage.

Abstract: A radio frequency amplifier system is disclosed in which the amplifier bias supply and power supply voltages are instantaneously modulated with signals derived from the envelope voltage of the input signal. Separate non-linear mapping functions are used to derive the supply and bias voltages. The two mapping functions are optimised jointly to achieve particular system performance goals, such as optimum efficiency, constant gain, constant phase, or minimum spectral spreading. An optimisation of particular interest is that which achieves best RF amplifier power added efficiency subject to achieving constant amplifier gain. In this way the need for pre-distortion linearization may be reduced or eliminated.

Abstract: A radio frequency amplification stage comprising: an amplifier for receiving an input signal to be amplified and a power supply voltage; and a power supply voltage stage for supplying said power supply voltage, comprising: means for providing a reference signal representing the envelope of the input signal; means for selecting one of a plurality of supply voltage levels in dependence on the reference signal; and means for generating an adjusted selected power supply voltage, comprising an ac amplifier for amplifying a difference between the reference signal and one of the selected supply voltage level or the adjusted selected supply voltage level, and a summer for summing the amplified difference with the selected supply voltage to thereby generate the adjusted supply voltage.

Abstract: When an output voltage from the amplifying circuit includes a positive DC voltage, an electric current continuously flows in a power source voltage, a load, and a reference voltage in this order. As a result, the reference voltage increases so as to be a first threshold voltage or more. The detecting section detects that the reference voltage is the first threshold voltage or more. When the output voltage from the amplifying circuit includes a negative DC voltage, an electric current continuously flows in the reference voltage, the load, a grounding potential in this order. As a result, the reference voltage reduces so as to be a second threshold voltage or less. The detecting section detects that the reference voltage is the second threshold voltage or less.

Abstract: A method and apparatus for a power amplifier module is described. The module includes a power amplifier and a power supply modulator coupled to the power amplifier. In addition, the module includes an inverter coupled between the power amplifier and the power supply modulator. The inverter provides a predistorted signal to the power amplifier to cancel distortion in the power amplifier provided by the power supply modulator. In addition, the module can include a driver coupled between the power amplifier and the inverter wherein the driver supplies the predistorted signal to the power amplifier.

Abstract: The present invention discloses a multi-voltage headphone driver circuit comprising: at least one operational amplifier having an output supplied to a headphone speaker, the operational amplifier receiving a first power supply as its high operation voltage; a charge pump receiving a second power supply to generate a negative voltage corresponding to the second power supply in magnitude; and an m-fold circuit multiplying the negative voltage by m and providing the result to the operational amplifier as a low operation voltage thereof, wherein m is a real number.

Abstract: A power amplifying apparatus includes a high-speed low pass filter which inputs an envelope signal included in a transmission signal therein, a low-speed low pass filter which inputs the envelope signal therein, a determination unit which inputs the envelope signal therein and determines rising or falling of the envelope signal, a selecting unit which selects one of the high-speed low pass filter and the low-speed low pass filter according to a determined result of the determination unit, and a voltage supply unit which generates a voltage based on a signal input according to a selection by the selecting unit and supplies the voltage to a power amplifier which inputs the transmission signal therein so as to amplify a power of the transmission signal.

Abstract: An automatic gain control device includes amplifiers cascaded, each having a variable gain; level measurement portions respectively corresponding to the amplifiers, where each of the level measurement portions measures a level of an output signal of a corresponding one of the amplifiers in a level measurement period indicated by a level measurement signal; error calculators respectively corresponding to the level measurement portions, where each of the error calculators compares a level measured by a corresponding one of the level measurement portions with a threshold which is set so that a corresponding one of the amplifiers will not saturate, and outputs a comparison result as an error signal; a gain computation section which updates one of the gains of the amplifiers at a time corresponding to a gain update signal, based on the error signals; and an operation controller which generates the level measurement signal and the gain update signal.

Abstract: A calibration unit calibrates a power amplifier load impedance to achieve a nominal amplifier load impedance after the connection of one or more external elements, e.g., antenna, to improve the accuracy and effectiveness of output power calibration. The calibration unit comprises an adaptive impedance unit and a controller. The adaptive impedance unit includes first and second variable impedance elements connected between the amplifier and the external load, e.g., antenna. The controller independently calibrates the imaginary and real parts of the load impedance by respectively selecting first and second calibration values for the first and second variable impedance elements based on a reference voltage. More particularly, the controller selects calibration values for the first and second variable impedance elements from a plurality of impedance values based on a comparison between a reference voltage and the calibrated voltages produced at the output of the power amplifier responsive to the impedance values.

Abstract: There is disclosed a multi-stage amplifier comprising: a first amplifier stage; a second amplifier stage; a first voltage supply stage arranged to provide a supply voltage to the first amplifier in dependence on an average power of a signal to be amplified; and a second voltage supply stage arranged to provide a supply voltage to the second amplifier in dependence on an instantaneous power of a signal to be amplified.

Abstract: A controller enables the integration of a DC-DC converter in an amplitude modulation power control loop in a mobile handset. The controller includes an input conditioner and an event sensor. The input conditioner uses a peak detector to track the output of a regulator and responds to available baseband input signals. The event sensor controls a switch that connects the DC-DC converter to a battery in response to a bypass event. The controller bypasses the DC-DC-converter when a transmitter is not enabled. The DC-DC converter is enabled prior to a transmission burst. A target voltage is determined from a series of detected peak voltages from the output of the regulator. The controller commands the DC-DC converter to transition to the target voltage until the end of a transmission burst.

Abstract: An apparatus and method amplify a signal for use in a wireless network. The apparatus includes a power amplifier, an envelope modulator, a tunable matching network (TMN), and a controller. The power amplifier outputs the signal at an output power. The envelope modulator controls a bias setting for the power amplifier. The TMN includes a plurality of immittance elements. The controller is operably connected the envelope modulator and the TMN. The controller identifies a desired value for the output power of the power amplifier, controls the output power of the power amplifier by modifying the bias setting of the power amplifier, and sets a number of the plurality of immittance elements based on the bias setting of the power amplifier.

Abstract: The embodiments of the present circuit and method disclose an amplification circuit including a voltage regulator, a negative charge pump and an amplifier. The output of the voltage regulator supplies the upper voltage supply of the amplifier and the output of the negative charge pump supplies the lower voltage supply of the amplifier. The voltage regulator and the negative charge pump make the power supply of the amplifier flexible, easy to be fabricated in semiconductor process.

Abstract: A power management system for a radio frequency (RF) power amplifier (PA) load is disclosed. The power management system includes a first switching power supply that is adapted to output a relatively constant voltage, an electronic switch for selectively coupling the first switching power supply to the RF PA load, and a second switching power that is adapted to output a dynamic DC voltage to the RF PA load. The power management system further includes a control system that is adapted to close the electronic switch to supply the relatively constant DC voltage in addition to the dynamic DC voltage to the RF PA load in a first mode and to open the electronic switch wherein the relatively constant DC voltage is not supplied to the RF PA load in a second mode.

Abstract: An electronic circuit is disclosed for driving a switching amplifier. The electronic circuit is configured for generating, when operating in a switch-on mode, a driving signal for driving the switching amplifier. The driving signal carries a plurality of pulses having: an pulse width increasing between contiguous pulses of the plurality of pulses according to a step value having modulus equal to two and odd values; a polarity alternating between the contiguous pulses.

Abstract: A driver circuit for a semiconductor laser diode (LD) is disclosed, in which the driver circuit drives the LD in the differential mode and lowers the power consumption thereof. The driver circuit includes a differential unit to provide the modulation current to the LD, a voltage converter to provide a positive power supply to the differential unit, a detector to detect the common mode voltage of the differential outputs of the unit, and a comparing unit to control the voltage converter dynamically such that the output common mode voltage is set in a preset reference level.

Abstract: A dB-linear voltage-to-current (V/I) converter that is amenable to implementation in CMOS technology. In a representative embodiment, the dB-linear V/I converter has a voltage scaler, a current multiplier, and an exponential current converter serially connected to one another. The voltage scaler supplies an input current to the current multiplier based on an input voltage. The current multiplier multiplies the input current and a current proportional to absolute temperature and supplies the resulting current to the exponential current converter. The exponential current converter has a differential MOSFET pair operating in a sub-threshold mode and generating an output current that is proportional to a temperature-independent, exponential function of the input voltage.

Abstract: This is disclosed an amplification stage including a first amplifier stage, a second amplifier stage, and a power supply unit, in which the output of the first stage provides the input to the second stage, and the power supply unit provides a power supply for both amplifier stages, wherein the voltage of the power supply is continuously varied in dependence of the amplitude of the signal being amplified.

Abstract: A communication device is presented that has different processors and a power amplifier. One of the processors receives a signal from a monitor and indicates that an alarm exists to a diagnostics module. The other processor uses the envelope signal of the input signal to be amplified and either the signal from the diagnostics module, the monitor or the power amplifier to adjust modulation of the power supply of the power amplifier dependent on the type of alarm. The power supply voltage or headroom is maximized or frozen at the value of the last detection cycle if a fault or impairment, respectively, of the power amplifier is detected.

Abstract: A power amplifier controller circuit controls a power amplifier based upon an amplitude correction signal indicating the amplitude difference between the amplitude of the input signal and an attenuated amplitude of the output signal. The power amplifier controller circuit comprises an amplitude control loop and a phase control loop. The amplitude control loop adjusts the supply voltage to the power amplifier based upon the amplitude correction signal. The RF power amplifier system may reduce the corrective action of the amplitude loop during periods of relatively rapid changes in amplitude, and thus distortion can be further reduced.

Abstract: A radio is presented that has a processor, memory, modulator and a power amplifier. An envelope of a signal to be transmitted is used by the processor to control modulation of the voltage of the power amplifier by the modulator between a desired minimum voltage and a desired maximum voltage. Using the memory, the desired minimum voltage is determined from the desired maximum voltage and these voltages are less than nominal minimum and maximum voltage, respectively. The desired minimum voltage is tailored for the radio and takes into account environmental conditions to optimize operating conditions for the radio. If the range of voltages would exceed the dynamic range of the radio, the modulation provided by the modulator is controlled by the processor in steps until the desired minimum and maximum voltages are achieved.

Abstract: A current control circuit for controlling a bias current of a class AB operational amplifier includes: a low current source, for generating a low bias current; a high current source, for generating a high bias current, which is greater than the low bias current; and a comparing and selecting unit, coupled to an output terminal of the class AB operational amplifier, for selecting one of the low bias current and the high bias current to output as the bias current according to an output voltage of the class AB OP.

Abstract: An apparatus includes an envelope tracking power supply configured to control a power amplifier. The power supply includes a first amplifier configured to receive an input voltage and generate a supply voltage for the power amplifier. The power supply also includes a second amplifier configured to receive a shifted input voltage. An output of the second amplifier is coupled to the first amplifier. The first amplifier is configured to maintain an operational mode of the power amplifier. The power supply could further include a third amplifier. An output of the third amplifier is coupled to an input of the second amplifier, and the third amplifier is configured to receive a second shifted input.

Abstract: A system for controlling amplifier power is provided. The system includes a voltage envelope detector receiving a voltage signal and generating an attenuated voltage envelope signal. A current envelope detector receives a current signal and generates an attenuated current envelope signal. A controller receives power level data and generates attenuation control data for the voltage envelope signal and the current envelope signal. A detector receives the voltage envelope signal and the current envelope signal and generates a control signal based on the greater of the voltage envelope signal and the current envelope signal. A power amplifier level controller receives the control signal and generates a power amplifier level control signal.

Abstract: When switching the mode of a power amplifier between a compressed mode and an uncompressed mode, an accurate transmission power control is realized. A transmission power control method includes calculating an intra-mode output power error from a power setting value in a mode before switching as a comparison standard value error (equal to step ST32), setting a power setting value of a mode to switch to, such that an inter-mode output power error is canceled (equal to step ST33), calculating an intra-mode output power error from a power setting value of a mode to switch to (equal to step ST35), calculating a gain linearity value based on a power setting value of a mode to switch to and the intra-mode output power error (equal to step ST36), and resetting the power setting value of the mode to switch to, that cancels the comparison standard value error in the mode before switching and the output power error in the mode to switch to, based on the gain linearity value (equal to steps ST37 and 38).

Abstract: Green Design is to save the resource and energy for earth. Applying the recycling of energy concept to the electrical and electronic device and circuit, we can save many nuclear power plants to save the earth and human society. Comparing with today power amplifier PA has only 10% efficiency, the high linearity and high efficiency power-managing amplifier PMA and differential power managing amplifier DPMA can have the power efficiency more than 95%. The recycling switch inductor drive power management unit PMUx gets rid of the switch loss and has power efficiency more than 99%. The Xtaless Clock generator based on on-chip gain-boost-Q LC tank and the Spurfree and Jitterless Frequency & Phase Lock Loop FPLL. The DPMA directly supply the power to the plasma light. The charge doped light mirror reduces the voltage swing, increases the power efficiency and operating speed of plasma light, projective TV, LaserCom.

Abstract: The invention relates to a method for amplifying a carrier signal (CS1) by using a power amplifier (PA1), the power amplifier (PA1) is feed with a supply voltage (PASV1) of a power supply (SMPS1). The method comprises the step of adapting a value of the supply voltage (PASV1) to a value related to a mean signal power of an input signal (DS) of a power amplifier system (PAS1).

Abstract: An electronic circuit includes an amplifier that amplifies an input signal, a control circuit configured to generate a control signal by averaging an output signal of the amplifier based on a time constant, a first time constant control circuit configured to generate a first time constant control signal based on the control signal, the first time constant control signal changing the time constant of the control circuit to a second time constant from a first time constant smaller than the second time constant, a second time constant control circuit configured to generate a second time constant control signal by averaging the output signal of the amplifier based on a third time constant between the first time constant and the second time constant, the second time constant control signal changing the time constant of the control circuit to the first time constant from the second time constant, and a bypass circuit bypassing the input signal of the amplifier based on the control signal.

Abstract: An audio amplifier such as for driving headphones. The amplifier includes multiple amplifier devices coupled in parallel. Both a bias generator and a volume control are responsive to a user setting. Under low output signal conditions, one or more of the amplifier devices are disabled in response to the user setting. Disabled amplifier devices do not consume output bias current. Thus the audio amplifier has reduced power consumption, and the system has longer battery life.

Abstract: A method for determining pre-distortion of a power amplifier includes the following steps: providing a first power input signal to make the power amplifier generate a first power output signal; receiving a first receiving signal, which is acquired according to the first power output signal; detecting a predetermined gain of the power amplifier by means of the first power input signal and the first receiving signal; providing a second power input signal to make the power amplifier generate a second power output signal; receiving a second receiving signal, which is acquired according to the second power output signal; determining pre-distortion amplitude values and pre-distortion phase values of the power amplifier by means of the predetermined gain, the second power input signal and the second receiving signal.

Abstract: Disclosed are voltage distribution device and method for controlling CMOS-based devices for switching radio frequency (RF) signals. In certain RF devices such as mobile phones, providing different amplification modes can yield performance advantages. For example, a capability to transmit at low and high power modes typically results in an extended battery life, since the high power mode can be activated only when needed. Switching between such amplification modes can be facilitated by one or more switches formed in an integrated circuit and configured to route RF signal to different amplification paths. In certain embodiments, such RF switches can be formed as CMOS devices, and can be based on triple-well structures. In certain embodiments, various bias voltages applied to such a CMOS RF switch can be facilitated by a voltage distribution component.

Abstract: An apparatus for sensing power amplifier current includes a system voltage source that is used to develop a reference voltage, a wire bond structure connected between the system voltage source and a power amplifier, where a sense voltage developed across the wire bond structure is indicative of a current flowing through the power amplifier, and a current source configured to compensate the reference voltage for changes in resistance of the wire bond structure due to a temperature coefficient of the wire bond structure.

Abstract: When switching the mode of a power amplifier between compressed mode and uncompressed mode, accurate transmission power control is realized. A transmission power control method includes setting a power setting value of mode to switch to, such that an inter-mode output power error is canceled (equal to step ST21), calculating an intra-mode output power error from the power setting value of the mode to switch to (equal to step ST23), calculating a gain linearity value based on the power setting value of the mode to switch to and an output power error of the intra-mode (equal to step ST24), and resetting the power setting value of the mode to switch to based on the gain linearity value (equal to steps ST25 and 26).

Abstract: A mobile terminal and method of controlling a driving voltage of a power amplifier therein are provided. The present invention includes a power amplifier module having a plurality of operative modes, the power amplifier module configured to amplify a power strength of an RF signal, a modem configured to deliver the RF signal to the power amplifier module, and to control the operative modes of the power amplifier module, a power detecting unit configured to output a reference voltage by detecting the power strength of the RF signal outputted from the power amplifier module, and a DC/DC converter configured to supply a driving voltage to the power amplifier module by adjusting a detected power value according to a gain corresponding to each of the operative modes of the power amplifier module.

Abstract: Aspects of a method and system for amplitude calibration for polar modulation with discontinuous phase may include amplifying a signal via a plurality of amplifiers such that a combined gain of the plurality of amplifiers comprises a coarse amplitude gain, an amplitude offset gain and a calibration gain. A gain of one or more of the plurality of amplifiers may be adjusted to set the coarse amplitude gain, and a gain of one or more remaining ones of the plurality of amplifiers may be adjusted to set the amplitude offset gain and the calibration gain. The setting of the coarse amplitude gain, the calibration gain and/or said amplitude offset gain may be adjusted dynamically and/or adaptively.

Abstract: In a wireless communication apparatus in a time division duplex system, a transmission signal generation unit generates a transmission signal. A power amplifying device amplifies the generated transmission signal. A control signal generation device generates a drain voltage control signal for control of the drain voltage of the power amplifying device, and a gate voltage control signal for control of the gate voltage of the power amplifying device. The switch unit switches off the drain power supply of the power amplifying device during reception in the time division duplex system according to the drain voltage control signal. In addition, the power amplifying device sets a higher gate voltage during reception in the time division duplex system higher than during transmission according to the gate voltage control signal.

Abstract: An apparatus for controlling a power amplifier configured to amplify radio frequency (RF) signal includes a detector and a controller. The detector is configured to detect a power level of the RF signal with respect to a predetermined power threshold and to generate a corresponding detection signal. The controller is configured to provide a control voltage to an output transistor of the amplifier based on the detection signal. The control voltage has a low voltage value, which is substantially the same as a value of a supply voltage, when the detection signal indicates that the power level is below the power threshold, and the control voltage has a high voltage value when the detection signal indicates that the power level is above the power threshold. The controller generates the high voltage value by boosting the supply voltage.