Showing papers on "Voltage multiplier published in 2007"

Ultra-High-Voltage Charge Pump Circuit in Low-Voltage Bulk CMOS Processes With Polysilicon Diodes

Abstract: An on-chip ultra-high-voltage charge pump circuit realized with the polysilicon diodes in the low-voltage bulk CMOS process is proposed in this work. Because the polysilicon diodes are fully isolated from the silicon substrate, the output voltage of the charge pump circuit is not limited by the junction breakdown voltage of MOSFETs. The polysilicon diodes can be implemented in the standard CMOS processes without extra process steps. The proposed ultra-high-voltage charge pump circuit has been fabricated in a 0.25-mum 2.5-V standard CMOS process. The output voltage of the four-stage charge pump circuit with 2.5-V power-supply voltage (VDD=2.5 V) can be pumped up to 28.08 V, which is much higher than the n-well/p-substrate breakdown voltage (~18.9 V) in a 0.25-mum 2.5-V bulk CMOS process

Development of Long-Range UHF-band RFID Tag chip Using Schottky Diodes in Standard CMOS Technology

Abstract: We present the design of three key building blocks for UHF-band passive RFID tag chip, i.e., voltage multiplier, ASK demodulator, and internal clock generator. An analysis on a simple equivalent circuit of RFID tag chip for long reading range is presented taking into account the finite turn-on voltage of tag chip. The Schottky diodes used in the passive RFID tag chip were fabricated using titanium (Ti/Al/Ta/Al)-silicon (n-type) junction in 0.35 mum CMOS process, and the effect of size of Schottky diode on the turn-on voltage and the input impedance of the voltage multiplier was investigated. For 300 mV RF input voltage, the fabricated voltage multiplier using Schottky diodes generated output voltages of 1.5 V and corresponding voltage conversion efficiency of 45%. In addition, we propose an example circuit for internal oscillator of tag chip with digital calibration, which can generate precise copy of RFID reader timing signals.

Circuit and method for a fully integrated switched-capacitor step-down power converter

Abstract: A circuit and method for providing a fully integrated DC-DC converter using on-chip switched capacitors is disclosed. A switched capacitor matrix is coupled as a digitally controlled transfer capacitor. A pair of non-overlapping, fixed frequency clock signals is provided to a switched capacitor circuit including the switched capacitor matrix and a load capacitor coupled to the output terminal. A DC input voltage supply is provided. A hysteretic feedback loop is used to control the voltage at the output as a stepped-down voltage from the input by digitally modulating the transfer capacitor using switches in the switch matrix to couple more, or fewer, transfer capacitors to the output terminal during a clock cycle. A coarse and a fine adjustment circuit are provided to improve the regulation during rapid changes in load power. A method of operating the regulator is disclosed.

An AA-Sized Vibration-Based Microgenerator for Wireless Sensors

Abstract: This paper deals with the vibration-to-electrical transducer that has an M-size form factor and generates a DC voltage that can power off-the-shelf integrated circuits. Vibration-powered wireless sensors obtain power from machine vibrations, human movement, or other forms of motion. The feasibility of incorporating micro power transducers (MPTs) with a voltage multiplier and rectifier to make a micro power generator (MPG) is demonstrated, that has the same size and shape as an AA battery. The AA-sized module includes a voltage multiplier and a large capacitor to produce the DC output

A robust, input voltage adaptive and low energy consumption level converter for sub-threshold logic

Abstract: A new level converter (LC) is proposed for logic voltage shifting between sub-threshold voltage to normal high voltage. By employing 2 PMOS diodes, the LC shows good operation robustness with sub-threshold logic input. The switching delay of the proposed LC can adapt with the input logic voltage which is more suitable for power aware systems. With a simpler circuit structure, the energy consumption of the LC is smaller than that of the existing sub-threshold LC. Simulation results demonstrate the performance improvement and energy reduction of the proposed LC. Test chip was fabricated using 0.18 mum CMOS process. Measurement results show that our proposed LC can operate correctly with an input at as low as 127 mV and an output voltage at 1.8V.

Modeling and Design of CMOS UHF Voltage Multiplier for RFID in an EEPROM Compatible Process

Abstract: Modeling and design of CMOS ultra-high-frequency (UHF) voltage multipliers are presented. These circuits recover power from incident radio frequency (RF) signal and supply battery less UHF RF identification (RFID) transponders. An analytical model of CMOS UHF voltage multipliers is developed. It permits to determine the main design parameters in order to improve multiplier performance. The design of this kind of circuits is then greatly simplified and simulation time is reduced. Thanks to this model, a voltage multiplier is designed and implemented in a low-cost electrically erasable programmable read-only memory compatible CMOS process without Schottky diodes layers. Measurements results show communication ranges up to 5 m in the U.S. standard.

A Breakdown Voltage Multiplier for High Voltage Swing Drivers

Abstract: A novel breakdown voltage (BV) multiplier is introduced that makes it possible to generate high output voltage swings using transistors with low breakdown voltages. The timing analysis of the stage is used to optimize its dynamic response. A 10 Gb/s optical modulator driver with a differential output voltage swing of 8V on a 50 Omega load was implemented in a SiGe BiCMOS process. It uses the BV-Doubler topology to achieve output swings twice the collector-emitter breakdown voltage without stressing any single transistor

Capacitance measurement systems and methods

Abstract: A first capacitor and a second capacitor are charged until voltage at the second capacitor settles to a settling voltage. While charging, the first capacitor is alternately switched between a current source and ground. When the settling voltage is reached, charging of the first capacitor is halted. The second capacitor continues to be charged until voltage at the second capacitor reaches a reference voltage. The amount of time it takes for the settling voltage to reach the reference voltage corresponds to a measure of capacitance on the first capacitor.

A Step-Up DC–DC Converter With a Resonant Voltage Doubler

Abstract: A step-up dc-dc converter with a resonant voltage doubler is proposed. The proposed converter is composed of an active-clamp circuit and a resonant voltage doubler. The active-clamp circuit, which is controlled by dual asymmetrical pulsewidth modulation of the primary side, reduces the voltage spikes of main switches and limits the voltage stress of the switches as the maximum input voltage. In addition, the resonant voltage doubler of the secondary side provides two resonant-current paths formed by the leakage inductance and the output resonant capacitors, and zero-current-switching turn-off of diodes can be achieved by their resonant current. Thus, the losses of the output diodes due to the reverse-recovery problem can be removed. In addition, the voltage stress of the output diodes is clamped to the output voltage. The operation and analysis of the proposed circuit is presented in detail. To verify the performance of the proposed converter, experimental results are carried out for a 1.2-kW dc-dc converter with a constant switching frequency of 70 kHz.

Charge pump circuit for high voltage generation

Abstract: A circuit and method are given, to realize a high efficiency voltage multiplier for integrated circuits generating an internal and flexible positive or negative high voltage on-chip supply voltage from low external positive or negative supply voltages or ground. Applying multi-phase control signals to voltage boost internal nodes allows for eliminating threshold voltage drop losses and thus improves the voltage pumping gain compared to circuits with diode-configured FETs of prior art. Making use of voltage signals from antecedent stages in order to bias the bulk of MOS transistors fabricated in triple-well technology enables relaxing of the gate oxide stress within high order stage MOS transistors. Such a method, called leap-frog bulk potential tracking method, makes MOS transistors from different stages exhibit about the same body effect, which is very important because MOS transistors of higher order stages now show the same performance as MOS transistors from lower order stages. Important also in terms of efficiency as the charge sharing speed of high order MOS transistors always dominates the total charge pump performance and the driving force of pumped currents, thus also allowing for a greater number of serially connectable stages overall or a smaller number necessary for a certain targeted output voltage.

Dc-dc converter, liquid crystal display device, aging test apparatus of liquid crystal display device, and method thereof

Abstract: A gate-on voltage/LED driving voltage generator includes an inductor boosting an input voltage through a PWM voltage and the input voltage, a diode and capacitor rectifying the boosted voltage, a first output terminal outputting the rectified voltage to supply an LED driving voltage to an LED, and a second output terminal supplying the rectified voltage to a gate driving circuit. Further, an aging test apparatus of an LCD device, which includes a high LED driving voltage generator in an HVS power board, and an HVI power board, may selectively perform an aging test according to a backlight unit of the LCD. Further, a DC-DC converter having the gate-on voltage/LED driving voltage generator, and the LCD including the DC-DC converter are provided.

Constant voltage circuit and constant current source, amplifier, and power supply circuit using the same

Abstract: A constant voltage circuit is disclosed that includes a constant voltage generator circuit part converting an input voltage into a predetermined constant voltage in accordance with an externally input control signal and outputting the constant voltage; a first capacitor connected to the output end of the constant voltage generator circuit part; a second capacitor charging the first capacitor; and a switch circuit part controlling charging and discharging of the second capacitor in accordance with the control signal. The switch circuit part charges the second capacitor and blocks the discharging of the second capacitor to the first capacitor when the constant voltage generator circuit part is caused to stop outputting the constant voltage by the control signal, and stops applying the input voltage to the second capacitor and charges the first capacitor when the constant voltage generator circuit part is caused to start outputting the constant voltage by the control signal.

Self-supply micro radio sensing network node based on the piezoelectric vibration power generation

Abstract: The related self-powered minimize wireless sensor network node for state monitor based on piezoelectric vibration comprises: a piezoelectric vibration power 1 including a long-term storage capacitor 10, a DC/DC converter 9, a voltage stabilizing tube 8, a voltage multiplier 7, and a piezoelectric transducer 6; a microcontroller 4 to operate the power supply of capacitor 10 to device 3 through a controlling switch 6, a RF transmitting device 3, and a sensor 5. Besides, the microcontroller 4 also processes data from sensor 5 and transmits result and control information together to device 3. This invention minimizes node power consumption.

A Bipolar Cockcroft-Walton Voltage Multiplier for Gas Lasers

Abstract: A bipolar Cockcroft-Walton Voltage Multiplier (CWVM) is proposed as an attractive alternative to the symmetrical Cockcroft-Walton voltage multiplier for continuous wave gas lasers (e.g. carbon dioxide gas laser). The proposed CWVM formed by combining positive and negative voltage multipliers consisting of equal number of stages and driving in parallel by an ac voltage source. The proposed voltage multiplier needs only one ac power source, therefore there was no need of center taped high voltage transformer, unlike symmetrical voltage multiplier which require center-tape transformer. It possess inherit ability of cancellation of fundamental and higher order odd harmonics of ripple components, unlike the symmetrical CWVM which may generate odd harmonic of ripple in case of any asymmetry of driving voltage. In addition to this the proposed voltage multiplier has faster transient rise and less voltage drop as compared symmetrical CWVM. The experimental and simulation results are presented to show the effectiveness of proposed voltage multiplier.

VLSI Implementation of a 4 x 4-bit Multiplier in a Two Phase Drive Adiabatic Dynamic CMOS Logic

Abstract: An adiabatic logic is a technique to design low power digital VLSI's. This paper describes the design and VLSI implementation of a multiplier using a two phase drive adiabatic dynamic CMOS logic (2PADCL) circuit. Circuit operation and performance have been evaluated using a 4 x 4-bit 2PADCL multiplier fabricated in a 1.2 μm CMOS process. The experimental results show that the multiplier was operated with clock frequencies 800 kHz. The total power dissipation of the 4 x 4-bit 2PADCL multiplier was also 5.19mW at the 1.5 V DC power supply voltage.

A low-voltage, low-power, high-linearity cmos four-quadrant analog multiplier

Abstract: A compact four-quadrant analog multiplier circuit using strong inversion saturated MOSFETs is presented. The circuit is formed by connecting simple 2-input "combiner" and "subtracter" cells in a novel topology. The proposed multiplier features low-voltage operation, very low quiescent power consumption, high-linearity and high operating frequency. In comparison with a previously reported multiplier circuit, simulated results using a 0.35-mum CMOS process show that, under the same static power consumption and supply voltage level of 1.2-V, the proposed circuit exhibits better linearity.

High efficiency charge pump DC to DC converter circuits and methods

Abstract: In one embodiment the present invention includes a voltage converter operable in both buck and boost modes. The voltage converter may only include one switched capacitor. A programmable current source, which may be implemented as a switch array, generates a current into the switch capacitor during a first time period to produce a voltage across the capacitor. During a second time period, the voltage may be transferred to the output of the converter, or boosted by coupling the input voltage to one terminal of the switched capacitor coupling the other terminal of the capacitor to the output. A feedback circuit is coupled to a controller for reprogramming the current into the capacitor to maintain the output voltage at desired levels.

Voltage detecting apparatus

Abstract: A voltage detecting apparatus for detecting a voltage of a direct current power source by using a capacitor, which can act processes for an abnormal voltage without elongation of measuring time, is provided. When a voltage between both terminals of the capacitor is over a maximum voltage in normal condition, a micro-computer discharges the capacitor through a third switch and a fourth switch to earth until the voltage between both terminals of the capacitor reduces to be not larger than a voltage corresponding to a maximum rated current of a reset switch. When the voltage between both terminals reaches to be not larger than the voltage corresponding to the maximum rated current, the capacitor is rapidly discharged through the reset switch by controlling the reset switch to be close.

High-dynamic range low ripple voltage multiplier

Abstract: A voltage multiplier ( 10 ) including a first clocked multiplier stage ( 12 ) having an input and an output and a second clocked multiplier stage ( 14, 16 ) having an input and an output is provided. The voltage multiplier further includes an input level regulator ( 18 ) coupled to the input of the first multiplier stage. The voltage multiplier further includes a feedback bias control circuit ( 32 ) coupled to the input level regulator, wherein the feedback bias control circuit is further coupled to receive the output ( 50 ) of the second multiplier stage, and wherein the feedback bias control circuit generates a feedback signal ( 58 ) affecting an output of the input level regulator based on a comparison between a voltage proportional to a voltage at the output of the second clocked multiplier stage and a reference voltage.

Power supply circuit and control circuit for use in the same

Abstract: A power supply circuit comprises a rectifier circuit (2) for converting an AC voltage to a DC voltage, a boost chopper circuit (3) for boosting an output voltage of the rectifier circuit based on a duty ratio signal; a smoothing circuit (4) for smoothing an output voltage of the boost chopper circuit; and a control means (5) for creating the duty ratio signal, the control means (5) is provided with a function for generating a DC voltage ripple information of the smoothing circuit, and correcting or modifying the duty ratio signal based on the DC voltage ripple information.

Capacitive sensor with ratiometric voltage references

Abstract: A capacitive sensor with ratiometric voltage references includes a voltage source, a charge transfer switch, an integrating capacitor, and a comparator. The voltage source is configured to generate a first voltage reference and a second voltage reference in response to a supply voltage, where the first voltage reference changes proportionally to the second voltage reference in response to a change in the supply voltage. The charge transfer switch is coupled to the integrating capacitor to distribute charge between a sensing capacitor and the integrating capacitor, where the charge is accumulated in response to the first voltage reference. The comparator is coupled to the second voltage reference and the integrating capacitor to compare a voltage on the integrating capacitor against the second voltage reference.

Inverter controller and method for operating the same

Abstract: An inverter controller comprising an AC motor as a load A rectifying circuit converts AC power from an AC power source into DC power A smoothing capacitor smoothens a DC voltage from the rectifying circuit An inverter circuit converts DC power supplied via the smoothing capacitor into a desired frequency A current detection circuit detects a output current of the inverter circuit A voltage detection circuit detects a terminal voltage (Vpn) of the smoothing capacitor A voltage command calculation circuit calculates a voltage command to the AC motor A speed command calculation circuit calculates a speed command to be used when it is determined that the AC power source is in a power failure state or when the terminal voltage (Vpn) reaches a certain value

Back-gate voltage generator circuit, four-terminal back gate switching fet, and charge and discharge protection circuit using same

Abstract: A back-gate voltage generator circuit generating a back-gate voltage of a four-terminal back gate switching MOSFET for charge and discharge control is disclosed. The back-gate voltage generator circuit includes first and second n-type MOSFETs connected in series through a common source electrode. A voltage at the common source electrode of the first and second n-type MOSFETS connected in series serves as the back-gate voltage of the four-terminal back gate switching MOSFET, and the back-gate voltage is used as a reference voltage for generating signals for controlling the first and second n-type MOSFETS.

High voltage tank assembly for radiation generator

Abstract: In one embodiment, a voltage rectifier circuit for a radiation generator is provided. The voltage rectifier circuit is configured to be used in a voltage multiplier circuit and a voltage doubler circuit. The voltage rectifier circuit comprises at least one first printed circuit board and at least one second printed circuit board coupled to each other using a plurality of connectors. Further, each printed circuit board comprises, a first terminal, a second terminal, a third terminal, a diode assembly externally connected between the first terminal and the second terminal and a capacitor assembly embedded between the second terminal and the third terminal.

Voltage controlled oscillator having temperature detecting circuit

Abstract: A VCO circuit includes a temperature detector circuit, a voltage generator circuit, a switch, a resonance circuit and an oscillator. The temperature detector detects a temperature, and the voltage generator circuit generates a voltage for coarse adjustment corresponding to the detected temperature and outputs the same voltage. The switch selects one of a DC voltage for fine adjustment and the voltage for coarse adjustment. The resonance circuit includes a varactor diode having a capacitance value adjusted based on the voltage selected by the switch, capacitors and an inductor, and has a predetermined resonance frequency. The oscillator generates an oscillation signal having an oscillation frequency corresponding to the resonance frequency by using the resonance circuit and outputs the same signal.

Dc-ac converter

Abstract: A DC-AC converter directly converts DC voltage to AC voltage. A voltage conversion circuit receives DC voltage at a pair of first input terminals, converts the DC voltage to voltage having a polarity corresponding to the AC voltage, and outputs the converted voltage from a pair of first output terminals insulated from the pair of first input terminals. The filter circuit receives the converted voltage at a pair of second input terminals, smoothes the converted voltage, and outputs the smoothed voltage as an AC voltage from a pair of second output terminals. A first switch circuit is arranged between the pair of first output terminals of the voltage conversion circuit and the pair of second input terminals of the filter circuit to operably connect the voltage conversion circuit and the filter circuit. A second switch circuit is arranged between the second input terminals of the filter circuit.

Variable load, variable output charge-based voltage multipliers

Abstract: A charge-based voltage multiplier device comprising a charge-pump circuit and a charge-pump controller is provided. The charge-pump circuit is configured to multiply an input voltage signal (Vin) into an output voltage signal (Vout), the charge-pump circuit includes a plurality of charge-pump stages, wherein at least one of the charge-pump stages includes a weighted capacitor array of pump cells. The charge-pump controller is configured to provide a pump cell select to selectively control the weighted capacitor array of pump cells of the at least one of the charge-pump stages of the charge-pump circuit.

A Wideband CMOS Multiplier for UWB Application

Abstract: This paper describes a novel wideband CMOS differential four-quadrant analog multiplier which is part of a integrated correlator aiming for application in Ultra-Wideband (UWB) transceiver. By combining a conventional Gilbert cell and a gate-source injection multiplier with flipped voltage followers together, wide operation bandwidth is achieved with enhanced conversion gain. Simulation results show that the multiplier can provide a bandwidth of up to 9.2 GHz and a conversion gain of 19 dB. This multiplier is able to operate with a 0.2 ns narrow monocycle pulse. The proposed circuit has been designed and simulated using commercial 0.18-mum CMOS process and the power consumption is 10.8 mW under a 1.8 V DC voltage supply.

Statistical Switched Capacitor Droop Sensor for Application in Power Distribution Noise Mitigation

Abstract: A circuit and a method for detecting noise events in a system with time variable operating points is provided. A switched capacitor filter comprising a plurality of capacitor units, samples a first voltage to determine an average of a set of voltage measurements, forming an average voltage. A filter control unit controls the plurality of capacitor units in the switched capacitor filter. A comparing unit compares the average voltage to the first voltage to form a comparison. A signaling unit generates a signal to instruct circuits in a processor to initiate actions to keep the first voltage from drooping below a threshold level in response to the comparison.

Dc-ac converter and method for protecting dc-ac converter from overcurrent

Abstract: A DC-AC converter for converting DC voltage to AC voltage. The converter includes a conversion circuit for converting DC voltage to voltage having a polarity corresponding to AC voltage. A filter circuit receives the converted voltage, smoothes the converted voltage, and outputs the smoothed voltage as AC voltage. A first switch operably connects the voltage conversion circuit and filter circuit. A second switch is arranged between input terminals of the filter circuit. An output current detection circuit detects overcurrent that is greater than a predetermined first threshold. When overcurrent that is greater than the first threshold is detected, the protection circuit stops the supply of power in the voltage conversion circuit, deactivates the first switch, and activates the second switch.