Fairchild Semiconductor Patent Applications

INDUCTOR CURRENT EMULATION FOR OUTPUT CURRENT MONITORING

Granted: November 30, 2017
Application Number: 20170346385
A switch mode power supply controller includes a switch terminal adapted to be coupled to an inductor that drives a load, high- and low-side switches a pulse width modulation (PWM) circuit, and a current monitor circuit. The PWM circuit is coupled to a feedback terminal for receiving a feedback signal, and alternatively drives the high-side switch and the low-side switch with a duty cycle set using the feedback signal to regulate an output voltage to a desired level in a work mode, and…

BYPASS CHARGING CIRCUIT AND METHOD

Granted: November 30, 2017
Application Number: 20170346328
In accordance with an embodiment, a bypass charging circuit includes a pair of transistors having current carrying terminals commonly connected to form a node. An input of a comparator is coupled to the node through a switch and to a resistor. Another input terminal of the comparator is coupled for receiving a reference voltage. Optionally, a transistor may be connected to the bypass charging circuit. In accordance with another embodiment a method is provided in which bypass charging…

AVALANCHE-RUGGED SILICON CARBIDE (SIC) POWER DEVICE

Granted: November 30, 2017
Application Number: 20170345889
In at least one general aspect, a silicon carbide (SiC) device can include a drift region and a termination region at least partially surrounding the SiC device. The termination region can have a first transition zone and a second transition zone. The first transition zone can be disposed between a first zone and a second zone, and the second zone can have a top surface lower in depth than a depth of a top surface of the first zone. The first transition zone can have a recess, and the…

RAMP GENERATOR FOR WIDE FREQUENCY RANGE PULSE WIDTH MODULATOR CONTROLLER OR THE LIKE

Granted: November 23, 2017
Application Number: 20170338807
A ramp generator includes a current generator, a current mirror, and a first capacitor. The current generator has an input for receiving a clock signal, and an output for providing a current proportional to a frequency of the clock signal using a first transistor having first and second current electrodes and a control electrode, an amplifier that establishes a reference voltage on the second current electrode of the first transistor, and a variable resistor coupled between the second…

METHODS AND APPARATUS RELATED TO PROTECTION OF A SPEAKER

Granted: October 19, 2017
Application Number: 20170303057
In one general aspect, a method can include calculating, at a calibration temperature of a speaker, a calibration parameter through a coil of the speaker in response to a first test signal, and can include sending a second test signal through the coil of the speaker. The method can also include measuring a parameter through the coil of the speaker based on the second test signal, and calculating a temperature change of the coil of the speaker based on the parameter and based on the…

SEMICONDUCTOR DEVICE AND METHOD THEREFOR

Granted: October 19, 2017
Application Number: 20170302185
In one embodiment, a power supply controller, or alternately a semiconductor device having a power supply controller, may have a first circuit configured to form a sense signal that is representative of a signal from an auxiliary winding of a transformer. A feedback circuit may be configured to allow the sense signal to increase in response to a turn-off of the power switch, to subsequently detect a second increase of the sense signal prior to subsequently turning on the power switch,…

SEMICONDUCTOR DEVICE AND METHOD THEREFOR

Granted: October 19, 2017
Application Number: 20170302184
In one embodiment, a power supply controller, or alternately a semiconductor device having a power supply controller, may have a circuit configured configuring the PWM circuit to form a first signal having a value formed to be representative of a peak value of a primary current through the power switch and having a duration that is representative of a time interval that a secondary current is flowing through a secondary winding wherein the peak value is the peak value during an on-time…

SILICON CARBIDE (SiC) DEVICE WITH IMPROVED GATE DIELECTRIC SHIELDING

Granted: October 5, 2017
Application Number: 20170288048
In one general aspect, an apparatus can include a silicon carbide (SiC) device can include a gate dielectric, a first doped region having a first conductivity type, a source, a body region of the first conductivity type, and a second doped region having a second conductivity type. The second doped region can have a first portion and a second portion. The first portion can be disposed between the first doped region and the body region and the second portion can be disposed between the…

GATE PRE-POSITIONING FOR FAST TURN-OFF OF SYNCHRONOUS RECTIFIER

Granted: August 24, 2017
Application Number: 20170244333
A synchronous rectifier driver pre-positions a gate of a synchronous rectifier to allow for fast turn-off. The synchronous rectifier driver turns ON the synchronous rectifier by driving the gate at a high level for a period of time that is based on a previous conduction time of the synchronous rectifier. The synchronous rectifier driver thereafter drives the gate at a lower level that is sufficient to keep the synchronous rectifier ON. The synchronous rectifier can be quickly turned OFF…

APPARATUS AND METHOD FOR RESTARTING AN ELECTRONIC DEVICE

Granted: August 17, 2017
Application Number: 20170235351
This document discusses, among other things, apparatus and methods for restarting an electronic device configured to receive power from a main power supply and an auxiliary power supply. The electronic device includes a reset circuit a reset circuit configured to provide a first signal indicative of an electronic device failure, and an isolation circuit configured to isolate the main power supply from the auxiliary power supply in response to the first signal so that power is supplied to…

SELF-TUNING ADAPTIVE DEAD TIME CONTROL FOR CONTINUOUS CONDUCTION MODE AND DISCONTINUOUS CONDUCTION MODE OPERATION OF A FLYBACK CONVERTER

Granted: August 3, 2017
Application Number: 20170222569
A flyback converter includes a primary-side switch that controls conduction of current on a primary side of a transformer and a synchronous rectifier on a secondary side of the transformer. A synchronous rectifier driver controls the conduction of the synchronous rectifier by adaptively adjusting a turn-off threshold of the synchronous rectifier.

ADAPTIVE TURN-OFF TRIGGER BLANKING FOR SYNCHRONOUS RECTIFICATION

Granted: August 3, 2017
Application Number: 20170222568
A switching converter includes a synchronous rectifier and a synchronous rectifier driver that controls conduction of the synchronous rectifier. The synchronous rectifier driver turns OFF the synchronous rectifier in response to a turn-off trigger. The synchronous rectifier driver prevents the turn-off trigger from turning OFF the synchronous rectifier during a turn-off trigger blanking time that is adaptively set based on a conduction time of the synchronous rectifier.

LOAD CAPACITANCE DETERMINATION CIRCUITRY AND POWER SUPPLY CONTROL

Granted: August 3, 2017
Application Number: 20170222557
Generally, this disclosure provides circuitry and methods for determining the output capacitance of an output load capacitor of a power supply. The output capacitance is generally determined by beginning a calibration period and charging an output capacitor with a current source to generate an output voltage. The output voltage may be compared to a reference voltage, and a time period is determined during which the output voltage is less than the reference voltage. The capacitance value,…

ENABLE AND DISABLE COMPARATOR VOLTAGE REFERENCE

Granted: July 13, 2017
Application Number: 20170201843
This document discusses, among other things, systems and methods to reduce power use of an accessory detection device. The accessory detection device can be configured to be coupled to a mobile device having an audio jack configured to be coupled to a mobile device accessory having a send/end key. In an example, the accessory detection device can include a comparator and a switch. The comparator can be configured to receive mobile device accessory information from the mobile device…

INPUT AC LINE CONTROL FOR AC-DC CONVERTERS

Granted: March 2, 2017
Application Number: 20170063225
An AC-DC converter includes a main switch that is controlled according to an input AC line voltage. The main switch is allowed to be switched when a level of the input AC line voltage is within a regulation band, and is prevented from being switched when the level of the input AC line voltage is not within the regulation band. The regulation band can be dynamically adjusted based on load condition. The AC-DC converter can be a buck, boost, or buck-boost converter.

ADAPTIVE CLAMPING CIRCUITRY

Granted: January 12, 2017
Application Number: 20170012545
The present disclosure provides A DC/DC power supply system that includes a primary side and a secondary side to generate an output DC voltage from an input DC voltage. The power supply also includes adaptive clamping circuitry configured to generate an adjustable clamping voltage and/or current to limit a Vds breakdown voltage for a plurality of switches of the secondary side.

CONTROL OF A STARTUP CIRCUIT USING A FEEDBACK PIN OF A PWM CONTROLLER INTEGRATED CIRCUIT CHIP

Granted: January 5, 2017
Application Number: 20170005583
A power supply includes a control transistor that controls a primary winding of a transformer to induce current on a secondary winding of the transformer to generate an output voltage. A pulse width modulation (PWM) controller integrated circuit (IC) chip drives the control transistor through a gate pin. The PWM controller IC chip has a feedback pin that receives a feedback signal indicative of the output voltage. A high voltage (HV) startup transistor is controlled through the feedback…

CHARGE PUMP CIRCUIT FOR PROVIDING VOLTAGES TO MULTIPLE SWITCH CIRCUITS

Granted: October 27, 2016
Application Number: 20160315534
A charge pump circuit generates a charge pump voltage that powers a bias circuit. The bias circuit generates a reference current and generates switch currents from the reference current. Gate-source voltages are generated from the switch currents and applied to switching components of switch circuits to connect two nodes. The gate-source voltages can be generated in the bias circuit and provided to the switch circuits. The gate-source voltages can also be generated in the switch…

ARTIFICIAL RIPPLE MODULATION CONTROL CIRCUITRY

Granted: September 29, 2016
Application Number: 20160285368
In one embodiment the present disclosure provides a power supply system that includes power switch circuitry configured to switch an input voltage to generate a switched input voltage; output circuitry including an inductor to generate an output voltage from the switched input voltage; and pulse width modulation (PWM) controller circuitry configured to generate a PWM signal to control the power switch circuitry; wherein the PWM controller circuitry is further configured to turn OFF the…

POWER SUPPLY WITH LINE COMPENSATION CIRCUIT

Granted: September 8, 2016
Application Number: 20160261196
A line compensation circuit for a power supply includes a line voltage sense circuit and a current limit adjuster. The line voltage sense circuit senses a slope of an inductor current by way of a compensation capacitor that receives a sense voltage that is representative of the inductor current on a primary side of the power supply. A compensation current that is generated from the compensation capacitor is used by the current limit adjuster to adjust an output current limit of the power…