Methods and apparatus related to protection of a speaker
Granted: July 3, 2018
Patent Number:
10015608
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…
Remote ground sensing for reduced crosstalk of headset and microphone audio signals
Granted: July 3, 2018
Patent Number:
10015578
Apparatus and methods for reducing crosstalk in personal audio equipment are provided. In an example, a method to reduce headset audio crosstalk can include applying a first signal to a first speaker channel of a headset, coupling a second speaker channel to a first input of a comparator of a crosstalk compensation circuit using a first switch of the crosstalk compensation circuit, the switch and detect circuit including the crosstalk compensation circuit, coupling a first resistor…
Control and current measurement function for battery charging, protection and fuel gauge coulomb counting
Granted: July 3, 2018
Patent Number:
10014695
In a general aspect, a battery pack can include a battery configured to supply power to a connected device and to receive re-charge power from a charger circuit. The battery pack can further include a current modulating circuit configured to modulate current of the battery between first and second supply terminals of the battery pack. The battery pack can also include a controller configured to provide voltage protection of the battery pack and charge current control of the battery using…
Hybrid gate dielectrics for semiconductor power devices
Granted: June 19, 2018
Patent Number:
10002941
In a general aspect, a power semiconductor device can include a silicon carbide (SiC) substrate and a SiC epi-layer disposed on the SiC substrate. The device can also include a first well region, a second well region disposed in the SiC epi-layer, a first source region disposed in the first well region, and a second source region disposed in the second well region. The device can further include a gate structure disposed on the SiC epi-layer and extending between the first source region…
USB interface detector
Granted: June 19, 2018
Patent Number:
10002061
Systems and methods are disclosed, including a USB interface detector, a detection method, a USB connector, and an electronic device. The detection method may be applicable to the USB connector mounted in the electronic device. According to an operation mode of the electronic device, a first pin and a second pin in the USB interface can be pulled up or pulled down. After the pull up or the pull down, a voltage change at the first and second pins are detected. If the voltage changes cross…
Gate pre-positioning for fast turn-off of synchronous rectifier
Granted: June 5, 2018
Patent Number:
9991810
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…
Packaged semiconductor devices with laser grooved wettable flank and methods of manufacture
Granted: May 22, 2018
Patent Number:
9978668
In a general aspect, a packaged semiconductor device can include a semiconductor device and a metal leadframe structure having a signal lead that is electrically coupled with the semiconductor device. The device can also include a molding compound encapsulating at least a portion of the metal leadframe structure. At least a portion of the signal lead can be exposed outside the molding compound. The device can further include a solder plating disposed on exposed portions of the metal…
Audio crosstalk calibration switch
Granted: April 3, 2018
Patent Number:
9936317
Methods and apparatus for calibrating an audio system including headset coupled to an electronic device via an audio dongle. In an example, a circuit configured to couple a Universal Serial Bus (USB) audio dongle with an audio circuit of an electronic device can include a first impedance configured to couple with a first audio channel of the audio circuit, a second impedance coupled in series with the first impedance and configured to couple with a second audio channel of the audio…
Ignition control circuit with current slope detection
Granted: March 20, 2018
Patent Number:
9920736
In a general aspect, a circuit for controlling operation of an ignition circuit including an insulated-gate bipolar transistor (IGBT) device can include a current slope detection circuit configured to detect a slope of a current in a primary winding of an ignition coil included in the ignition circuit and a driver circuit coupled with the current slope detection circuit. The current slope detection circuit can be further configured to, during charging of the ignition coil, if the…
USB adapter protection
Granted: March 20, 2018
Patent Number:
9923358
This document discusses, among other things, a protection system and method configured to detect a parasitic impedance between first and second pins of a standard connector and to remove a current path between a power source and a supply pin of the standard connector if a low-impedance is detected, in certain examples, without adding a current sense resistance to a return path between a ground pin of the standard connector and the power source.
Auxiliary self-protecting transistor structure
Granted: February 20, 2018
Patent Number:
9899370
This document discusses, among other things, an auxiliary self-protecting transistor circuit, system, and method configured to protect a complementary metal-oxide semiconductor (CMOS) transistor. The auxiliary self-protecting transistor circuit can include an ESD device including a gate terminal, a drain terminal, and a source terminal. The ESD device is configured to be coupled to an isolation region of a complementary metal-oxide semiconductor (CMOS) transistor, and can provide a…
Silicon-carbide trench gate MOSFETs
Granted: February 13, 2018
Patent Number:
9893176
In a general aspect, an apparatus can include a silicon carbide (SiC) trench gate MOSFET with improved operation due, at least in part, to a reduced gate capacitance. In the SiC trench gate MOSFET, a thick gate oxide can be formed on a bottom surface of the gate trench and a built-in channel, having a vertical portion and a lateral portion, can be formed to electrically connect a vertical inversion-layer channel, such as in a channel stopper layer, to a vertical JFET channel region and a…
Resonant converter control techniques to manage negative SR current
Granted: February 6, 2018
Patent Number:
9887633
This disclosure provides control techniques for a resonant converter. In one embodiment, a resonant converter controller includes predictive gate drive circuitry configured to generate a predictive gate drive signal indicative of a time duration from a rising edge of a first drive signal for controlling a conduction state of a first inverter switch of a resonant converter system to a synchronous rectifier (SR) current zero crossing instant of a first SR switch of the resonant converter…
Battery charging system including current observer circuitry to avoid battery voltage overshoot based on battery current draw
Granted: January 30, 2018
Patent Number:
9882408
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: January 23, 2018
Patent Number:
9877104
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…
Sealed packaging for microelectromechanical systems
Granted: January 2, 2018
Patent Number:
9856132
One example includes an integrated circuit including at least one electrical interconnects disposed on an elongate are extending away from a main portion of the integrated circuit and a microelectromechanical layer including an oscillating portion, the microelectromechanical layer coupled to the main portion of the integrated circuit, wherein the microelectromechanical layer includes a cap comprising a membrane that extends to the integrated circuit.
Enhanced protective multiplexer
Granted: December 5, 2017
Patent Number:
9838004
Systems and methods are disclosed, including a protection multiplexer circuit configured to receive a control signal and a reference voltage, to provide the reference voltage at an output when the control signal is in a first state, and to isolate the reference voltage from the output when the control signal is in a second state. The protection multiplexer circuit includes cascaded first and second transistors, wherein the first transistor is a native transistor. Control inputs of the…
Apparatus and method for extending analog front end sense range of a high-Q MEMS sensor
Granted: December 5, 2017
Patent Number:
9835647
Apparatus and methods for interfacing with a micro-electromechanical system (MEMS) sensor are provided. In an example, an apparatus can interface circuit including an integrator circuit, a sample switch circuit, a saturation detector and a controller. The saturation detector can be configured to receive a signal indicative of an integration of charge of the sensor, to compare the signal indicative of the integration of charge to an integrator saturation threshold and to modulate a divide…
Adaptive turn-off trigger blanking for synchronous rectification
Granted: November 21, 2017
Patent Number:
9825548
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.
Control of a startup circuit using a feedback pin of a PWM controller integrated circuit chip
Granted: November 7, 2017
Patent Number:
9812976
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…
