Fairchild Semiconductor Patent Applications

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…

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,…

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.

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.

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…

POWER SUPPLY WITH NEAR VALLEY SWITCHING

Granted: September 8, 2016
Application Number: 20160261201
A switched-mode power supply with near valley switching includes a quasi-resonant converter. The converter includes a switch element that is turned on not only at the valley, but also in a window range of ?tNVW close to the valley, where the voltage across the switch element is at its minimum. This advantageously reduces switching loss and maintains a balance between efficiency and frequency variation.

ADAPTIVE OVERVOLTAGE PROTECTION FOR ADAPTIVE POWER ADAPTERS

Granted: August 18, 2016
Application Number: 20160241016
A power adapter includes a protocol integrated circuit (IC) on a secondary side of a transformer and a controller IC on a primary side of the transformer. The power adapter has an output voltage that changes depending on the charging voltage requirement of an electronic device (e.g., mobile device) connected to receive power from the power adapter. The power adapter includes an adaptive overvoltage protection mode that sets an overvoltage protection threshold to a low level during…

BATTERY CHARGING SYSTEM INCLUDING CURRENT OBSERVER CIRCUITRY TO AVOID BATTERY VOLTAGE OVERSHOOT BASED ON BATTERY CURRENT DRAW

Granted: June 23, 2016
Application Number: 20160181834
According to one aspect of the present disclosure, there is provided a battery charging system. The battery charging system includes battery charging circuitry configured to provide charging current to a battery. The battery charging system further includes feedback circuitry configured to generate a feedback signal indicative of a battery charging condition, wherein the battery charging system is configured to control the battery charging current based on, at least in part, the feedback…

AUDIO SWITCH CIRCUIT WITH SLOW TURN-ON

Granted: June 23, 2016
Application Number: 20160182040
An audio switch circuit includes negative feedback paths and a transistor that serves as a switching component. The negative feedback paths are turned ON to couple a source voltage and a drain voltage of the transistor to the gate of the transistor when the audio switch circuit is turned ON. The negative feedback paths reduce the slew rate of the gate-to-source voltage of the transistor, thereby slowing the turn-ON of the audio switch circuit to prevent or minimize unwanted audible…

SWITCH DEVICE WITH SWITCH CIRCUITS THAT PROVIDE HIGH VOLTAGE SURGE PROTECTION

Granted: June 16, 2016
Application Number: 20160173084
A switch device includes a common node that is connected to end nodes, such as that of computer interface ports. The switch device includes several switch circuits that can be connected in series to form a switch path between the common node and an end node. A switch circuit can include a main switch, such as a transistor that can be configured to withstand a positive or negative voltage surge by automatically changing the connection of its gate.

CHARGE PUMP CIRCUIT FOR PROVIDING VOLTAGES TO MULTIPLE SWITCH CIRCUITS

Granted: June 9, 2016
Application Number: 20160164401
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…

FULL BRIDGE DC/DC CONVERTER CONTROL TECHNIQUES

Granted: December 17, 2015
Application Number: 20150365000
The present disclosure describes full bridge power supply systems and control methods. In at least one embodiment, the full bridge power supply system may be driven utilizing a two-phase continuous conduction switching mode to control the inductor current. In another embodiment, the full bridge power supply system may be driven utilizing variably-configured three-phase continuous conduction modes to control the inductor current when an input voltage is within a window value to the output…

OVERCURRENT DETECTION CIRCUIT AND METHOD, LOAD SWITCH, AND PORTABLE DEVICE

Granted: August 27, 2015
Application Number: 20150244164
The present invention provides an overcurrent detection circuit, an overcurrent detection method, a load circuit, and a portable device. The overcurrent detection circuit comprises: a first overcurrent detection sub-circuit and a second overcurrent detection sub-circuit; wherein: the first overcurrent detection sub-circuit is configured to perform overcurrent detection for a switch circuit when a voltage of an output terminal of the switch circuit is greater than or equal to a preset…