O2 Micro, Incorporated

O2micro International Limited

02 Micro International Limited

02micro Inc.

Serban Mihai Popescu

Laszlo Lipcsei

ChengHwa Teh

Marius Padure

Guoyong Guo

Sorin Hornet

Marian Udrea Spenea

Vlad Mihail Dan Popescu-Stanesti

Christian Andreev

Cristian Andreev

A converter circuit includes a converter and a controller. The converter converts an input voltage to an output voltage. The controller receives a reference voltage, generates a slew voltage having a substantially constant first slew rate if the reference voltage changes from a first level to a second level, and controls the converter based on the slew voltage to cause the output voltage to change from a third level to a fourth level at a substantially constant second slew rate.

Circuits and methods for controlling a DC/DC converter

A controller for a DC/DC converter includes multiple signal generators and a control circuit. The signal generators generate multiple pulse signals, each signal generator generating a corresponding pulse signal of the pulse signals and controlling the corresponding pulse signal to have a predetermined pulse width by counting a same preset number of cycles of a same oscillating signal. The control circuit selectively activates the signal generators according to an output of the DC/DC converter to generate the pulse signals.

Controllers for DC/DC converters

A controller includes an input selector, multiple cores and a multiplexer. The multiplexer is operable for multiplexing control signals to multiple output channels to provide multiple output signals. Each output channel can output a respective output signal, and each output signal represents a cyclic rotation of the control signals. The input selector is operable for enabling the cores to operate in a standby state alternately to control a multiplexing sequence of the control signals.

Controllers, systems and methods for implementing multi-phase control

A controller for a power converter includes a first amplification stage and a second amplification stage coupled to the first amplification stage. The first amplification stage generates a first amplified signal at a first terminal of an energy storage element according to an output signal the power converter. The second amplification stage generates a second amplified signal at a second terminal of the energy storage element and varies the second amplified signal in response to a change in the output signal. The second amplification stage further decreases the variation of the second amplified signal based on the first amplified signal.

Controllers for controlling output signals of power converters

A circuit includes a first resistor, a second resistor, a voltage follower and a current mirror. The first resistor converts a current flowing through the first resistor to a voltage drop between positive and negative sides of the first resistor. The second resistor is coupled to the negative side of the first resistor. The voltage follower is coupled to the positive side of the first resistor via a non-inverting terminal, and coupled to the negative side of the first resistor through the second resistor via an inverting terminal to cause a voltage at the inverting terminal to follow a voltage at the non-inverting terminal. The current mirror is coupled to the voltage follower to provide a sensing current proportional to the current flowing through the first resistor.

Circuits and methods for current sensing

A current sensing circuit includes a first resistor, a second resistor and a sense amplifier. The first resistor converts a current flowing through the first resistor to a voltage drop between positive and negative sides of the first resistor. The second resistor is coupled to the negative side of the first resistor. The sense amplifier is coupled to the positive side of the first resistor via a first pin of the sense amplifier, and coupled to the negative side of the first resistor through the second resistor via a second pin of the sense amplifier. The sense amplifier employs a negative feedback to generate a sensing current proportional to the current flowing through the first resistor.

A power regulator for converting an input voltage to an output voltage includes a pass device, a reference signal circuit and an error amplifier. The pass device receives the input voltage and provides the output voltage at an output terminal of the power regulator. The reference signal circuit coupled to the output terminal is powered by the output voltage to provide a reference signal. The error amplifier coupled to the pass device is powered by the output voltage to compare the reference signal with a feedback signal indicative of the output voltage. The error amplifier can generate a control signal according to a result of the comparison to drive the pass device.

Power regulator

A transistor comprises a substrate of a first conductivity type, a drain region and a source region of a second conductivity type, a gate, a gate oxide layer, an adjustment implant region of the first conductivity type and a planar junction. The drain region and the source region are disposed in the substrate. The gate is placed over the substrate between the source region and the drain region. The gate is separated from the substrate by the gate oxide layer. The adjustment implant region is disposed under the gate oxide layer and in the substrate. A second doping concentration of the adjustment implant region is higher than a first doping concentration of the substrate. The adjustment implant region and the drain region in a predetermined shape form the planar junction with a surface curvature pointing towards the drain region to relax electrical field intensity at a location of the planar junction.

Metal oxide semiconductor (MOS) transistors with increased break down voltages and methods of making the same

An amplifier that receives an input signal and outputs an amplified output signal includes an integration stage, a comparison stage, and a full bridge circuit. The integration stage is be used for receiving a constant common mode voltage, for receiving a first signal representing the input signal of the amplifier, and for generating a ramp signal. The comparison stage coupled to the integration stage is used for generating a pulse width modulation signal according to the ramp signal and according to a hysteretic signal. The full bridge circuit coupled to the comparison stage is used for receiving a power supply and the pulse width modulation signal, and for generating the output of the amplifier.

Class-D amplifier

Circuits and methods for controlling a converter are disclosed. A first switch within the converter can be turned off, and a second switch within the converter alternately can be turned on and off in response to a switch control signal while the first switch is turned off. By turning the second switch alternately on and off, energy stored in the converter can be recovered to a power source of the converter.

Circuits and methods for controlling a converter

A buck topology that provides voltage step up and polarity change is disclosed. In one embodiment a converter includes an input for receiving an input voltage, a switching circuit coupled to the input for receiving a first driving signal, a floating voltage source coupled to the switching circuit for producing an offset voltage, and an output coupled to the floating voltage source for generating an output voltage. The output voltage exhibits a voltage level that is directly proportional to a duty cycle of the first driving signal.

Buck topology allowing step-up and polarity change

A switching resistance linear regulator. The regulator comprises an output terminal producing a regulated output voltage, a first comparator, a second comparator, a first sourcing circuit coupled to the output terminal, and a first sinking circuit coupled to the output terminal. The first comparator compares a feedback signal representative of the output voltage and a first sourcing reference signal that is less than a reference signal. The second comparator compares the feedback signal and a first sinking reference signal that is greater than the reference signal. The first sourcing circuit is configured to be responsive to the first comparator by sourcing a first current to the output terminal. The first sinking circuit is configured to be responsive to the second comparator by sinking a second current from the output terminal.

Growing community of inventors

San Carlos, CA, United States of America

Serban Mihai Popescu