Richtek Technology Corporation

Hung-I Wang

Liang-Pin Tai

Jing-Meng Liu

Jian-Rong Huang

Shwu-Liang Hsieh

Jiun-Chiang Chen

Hsin-Hsin Ho

Kuo-Ping Liu

Kent Huang

Yu-Fan Liao

Chung-Lung Pai

Jing-Mong Liu

In a voltage regulator including an error amplifier to generate a first signal related to an output voltage of the voltage regulator, a current sense circuit to generate a second signal related to an inductor current of the voltage regulator, and a PWM comparator to generate a PWM signal in response to the first and second signals to regulate the output voltage, a current feed-through adaptive voltage position control comprises supplying ramp signal and offset signal to modify the PWM signal to thereby eliminate the offset of the output voltage.

Current feed-through adaptive voltage position control for a voltage regulator

In a voltage regulator including an inductor current flowing through a sense element with a first temperature coefficient, and a current sense circuit for generating a current sense signal related to the first temperature coefficient by sensing the inductor current from the sense element, a temperature compensation device and method determines a second temperature coefficient according to the first temperature coefficient and temperature variation, and produces a compensation signal with the second temperature coefficient to compensate variations in the current sense signal caused by the first temperature coefficient.

Temperature compensation device and method for a voltage regulator

A DC-to-DC converter comprises a sense circuit to sense the output voltage of the converter to generate a feedback signal, a transconductive amplifier to amplify a difference between the feedback signal and a threshold signal to generate a first current and to generate a second current in response to a load transient, a charging circuit connected with the first current to generate a charging voltage, a driver to compare the charging voltage with two reference signals to generate a pair of low-side and high-side driving signals, and a fast response circuit to compare a load transient signal corresponding to the second current with a third reference signal to generate a bypass signal to drive the output stage of the converter in the load transient.

DC-to-DC converter with fast load transient response and method thereof

To turn on a JFET, a two-stage turn-on current control is employed in a JFET driver circuit and a JFET driving method, by which a shortly pulsed high sourcing current is provided to turn on the JFET rapidly and efficiently, and a continuous low sourcing current is provided after the JFET turns on for reducing the power dissipation. After the JFET turns off, a negative charge pump is also employed to promise the JFET at a turn-off state. A special power sequence is further employed to ensure the JFET could be turned off during the power supply coupled to the JFET starts up.

JFET driver circuit and JFET driving method

A switching mode voltage regulator comprises a pulse width modulator and an adjustable one-shot circuit to generate an adjustable signal based on an input voltage, an adjustable voltage, and a PWM signal from the pulse width modulator at light loading to switch a high-side switch of an output stage in the voltage regulator. The ON duty of the adjustable signal is controlled by the adjustable voltage, such that it will be larger than that of the PWM signal and as a result, the number of switching the switch of the output stage is decreased, thereby reducing the switching loss and improving the efficiency of the voltage regulator.

Switching mode voltage regulator and method thereof

In a time-sharing current sense circuit for a multi-phase converter, a common transconductive amplifier is selectively connected to the channels of the converter power stage by a plurality of first switches under the control of a set of control clocks to detect the channel current of a selected channel among the channels so as to generate a sense current, and a sense current generated by the common transconductive amplifier from the sensed channel current is switched by a plurality of second switches under the control of the same control clocks to connect to one of a plurality of sampling-and-holding circuits each corresponding to one of the channels to generate a current sense signal to modulate the channel current of the selected channel.

Time-sharing current sense circuit for a multi-phase converter

A delta-sigma DC-to-DC converter comprises a pair of high-side and low-side switches switched to convert an input voltage to an output voltage, a sense circuit to sense the output voltage of the converter to generate a feedback signal, a transconductive amplifier to amplify a difference between the feedback signal and a threshold signal to generate a differential current, a charging circuit connected with the differential current to generate a charging voltage, and a driver to compare the charging voltage with two reference signals to generate the pair of low-side and high-side driving signals.

Delta-sigma DC-to-DC converter and method thereof

In a switching mode DC-to-DC power converter including a high-side transistor connected between an input voltage and an output node, a low-side transistor connected between the output node and a reference potential, and an inductor connected to the output node to derive an output voltage and an output current, a current sense apparatus and method employs a ramp signal generator to generate a ramp signal with a slope proportional to the difference between the input and output voltages, a DC signal generator to generate a DC signal proportional to the DC component of the current through the low-side transistor, and a summing circuit for combining the ramp and DC signals.

Current sense apparatus and method using a combination of a simulation and a real sense for a switching mode power converter

A current sense apparatus and method comprises a common drain DMOSFET and a MOSFET connected in series between a high voltage and a low voltage to serve as an output stage. The DMOSFET produces a phase output current, a mirror current mirrored from the phase output current, and a sense voltage. A servo amplifier is connected with the mirror current and sense voltage to produce a current sense signal. Due to the mirror current from the DMOSFET proportional to the phase output current, the current sense apparatus senses the phase output current in a temperature independent manner.

Current sense apparatus and method

A two-step ripple-free multi-phase buck converter and method thereof comprises a first-stage voltage regulator to convert an input voltage to an intermediate voltage and a second-stage voltage regulator with a phase number not less than two to further convert the intermediate voltage to an output voltage by a split phase control, in which the ratio of the intermediate voltage to the output voltage is intended to the phase number such that the steady state output current of the converter approaches to be ripple-free, and hence the drivers and MOSFETs for the second-stage voltage regulator are lower cost, the efficiency of the second-stage voltage regulator is improved, and a higher slew rate current is obtained for transient driving capabilities.

Two-step ripple-free multi-phase buck converter and method thereof

To balance the current of individual channel as well as regulate the output voltage for a multi-phase DC-to-DC buck converter, the converter output voltage is sensed and compared with a reference signal to produce a first error signal serving as first control signal for PWM signals of the converter and the channel currents are sensed, summed, averaged and subtracted to produce second error signals that are further modified by saw-tooth wave signal to produce second control signals for the PWM signals. Moreover, the reference signal is controlled by the summed channel currents for adjustable load regulation.

Multi-phase DC-to-DC buck converter with multi-phase current balance and adjustable load regulation

An apparatus and method for current balance in a multi-phase DC-to-DC converter with a converter output voltage and a plurality of channel currents employs for each channel a multi-input pulse width modulator or an ordinary pulse width modulator in conjunction with a multi-input comparator to produce a respective PWM signal to regulate the corresponding channel current. In addition to the comparison of the converter output voltage with a reference signal to produce an error signal, the apparatus and method compares the error signal with a ramp signal and the corresponding channel current with each of the other channel currents with the multi-input pulse width modulator. Alternatively, a ramp signal is compared by the ordinary pulse width modulator with a signal derived from the multi-input comparator which subtracts the corresponding channel current from each other channel current and sums the error signal.

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Changhua, Taiwan

Hung-I Wang