Texas Instruments Corporation

Jingwei Xu

Qingjie Ma

Vijayalakshmi Devarajan

Gianpaolo Lisi

Yang Wayne Wang

Wei Xu

Xianwei Zeng

Andrew Marshall

Ali Djabbari

Erhan Ozalevli

Angelo William Pereira

Mustapha El Markhi

Tuli Luthuli Dake

Gangqiang Zhang

William E Grose

Kosha Mahmodieh

Ruochen Zhang

Dingkun Du

Xiaofan Qiu

Jun Ma

Jian Jim Wang

Eugene G Dierschke

Jian Liang

Thomas A Schmidt

Marius Vicentiu Dina

Zhenghao Cui

Suribhotla Rajasekhar

Zbigniew Jan Lata

Yan He

Xianghao Meng

Kee-Chee Tiew

Ching L Lin

Salman Mazhar

Lindsay Langford

Alvin Xu

Michael Wang

Jianbo Guo

In a described example, an apparatus includes: a first metal oxide semiconductor field effect transistor (MOSFET) coupled between a first input terminal for receiving a supply voltage and an output terminal for coupling to a load, and having a first gate terminal; an enable terminal coupled to the first gate terminal for receiving an enable signal; a first current mirror coupled between the first input terminal and a first terminal of a first series resistor and having an input coupled to the first gate terminal; and a second MOSFET coupled between the first gate terminal and the output terminal, and having a second gate terminal coupled to the first terminal of the first series resistor, the first series resistor having a second terminal coupled to the output terminal.

Adaptive thermal overshoot and current limiting protection for MOSFETs

A wireless power transfer system using a resonant rectifier circuit with capacitor sensing. A wireless power transfer system includes a power receiver resonant circuit and a synchronous rectifier. The power receiver resonant circuit includes an inductor and a capacitor connected in series with the inductor. The synchronous rectifier is configured to identify zero crossings of alternating current flowing through the inductor based on voltage across the capacitor, and control synchronous rectification of the alternating current based on timing of the zero crossings.

Resonant rectifier circuit with capacitor sensing

An example apparatus includes a feedback loop to: change a direction value when a second current value is greater than a first current value, the second current value being obtained after the first current value; and maintain the direction value when the second current value is less than the first current value. When the direction value corresponds to a first direction value, a summer increases a reference signal by a step size. When the direction value corresponds to a second direction value different than the first direction value, the summer decrease the reference signal by the step size.

Methods and apparatus to increase efficiency for wireless power transfer

Systems and methods for wireless power transfer with fractional timing resolution are described. In some embodiments, an electrical power transmitter may include a transistor and a rising edge control circuit configured to control a gate of the transistor to produce a rising edge of a pulse at a time selected with a resolution greater than a full-clock period.

Wireless power transmission with fractional timing resolution

A wireless resonant power transmitter includes a first half-bridge and a second half-bridge adapted to be class D driven that are coupled to drive a series resonant circuit including a primary inductor (L) having a high side terminal and a low side terminal, and primary capacitor (C). A peak voltage sensor that includes a summing block is coupled across the high side terminal and the low side terminal of the primary L, and a peak-to-peak voltage detector is coupled to an output of the summing block to generate a DC voltage signal that is proportional to a peak-to-peak voltage across the primary C.

Peak voltage detection in a differentially driven wireless resonant transmitter

Methods and apparatus for detecting zero-volt crossing in a field-effect transistor. A comparator compares a drain-to source voltage of the transistor to a threshold voltage. A gate voltage signal of the transistor is provided to a clock input of the comparator such that said gate voltage signal is used to latch a result of said comparison to an output of the comparator. A control function with respect to the transistor is performed based on the value of the comparator output.

VDS comparator rise P, fall P, on late, off late outputs for ZVC timing

Methods, apparatus, systems and articles of manufacture to efficiently transfer power wirelessly are disclosed. An example apparatus includes a feedback loop to when a second current value is greater than a first current value, change a direction value, the second current value being obtained after the first current value; when the second current value is less than the first current value, maintain the direction value; and a summer to when the direction value corresponds to a first direction value, increase a reference signal by a step size; and when the direction value corresponds to a second direction value different than the first direction value, decrease the reference signal by the step size.

High-resolution FET VDS zero-volt-crossing timing detection scheme in a wireless power transfer system

Methods, apparatus, systems and articles of manufacture for negative output voltage active clamping using a floating bandgap reference and temperature compensation are disclosed. An example load switch includes a floating bandgap reference circuit to generate a bandgap reference voltage. A resistor divider is to generate a resistor divider voltage. A temperature compensator to apply a temperature compensation current to the resistor divider to create a temperature compensated resistor divider voltage. A power transistor is to be enabled when the temperature compensated resistor divider voltage is less than the bandgap reference voltage. The example load switch can work under negative output voltage clamping and get better accuracy drain to source clamped voltage of power transistor for inductive load condition.

Methods and apparatus for negative output voltage active clamping using a floating bandgap reference and temperature compensation

A gate driver IC for driving an NMOS transistor having a drain coupled through a load to a power supply. A gate driver output drives the gate of the NMOS transistor. A comparator receives the drain voltage of the NMOS transistor and compares it to a reference voltage representative of a short circuit condition between the drain and the power supply. The comparator outputs a first value if the drain voltage is greater than the reference voltage and outputs a second value if the drain voltage is less than or equal to the reference voltage. Control circuitry receives the output of the first comparator and pulls the voltage of the gate driver output low if the comparator output is of the first value. Adaptive masking circuitry is operable, upon an application of an 'on' signal to the gate driver output, to mask the output of the comparator such that a condition of the drain voltage being greater than the reference voltage does not cause the control circuitry to pull the voltage of the gate driver output low. The adaptive masking circuitry detects a Miller plateau in the gate voltage of the external NMOS transistor. The adaptive masking circuitry stops masking the output of the comparator after the end of the Miller plateau.

Masking vd to vref after miller plateau and gate charge

Adaptive blanking timer for short circuit detection

A method for generating an actuation signal for a light source is provided. A random phase delay for each period of an input signal is generated, where each period is a predetermined length. Each phase delay is added to a predetermined actuation period to generate a sum. The sum is compared to the predetermined length. At least one turn-on and at least one turn-off for each period of the input signal is calculated from the comparison of the sum to the predetermined length, and the actuation signal having each turn-on and each turn-off is generated.

Apparatus and method for dimming a backlight with pseudo-random phase delay

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Plano, TX, United States of America

Jingwei Xu