Patent application number | Description | Published |
20100001799 | AMPLIFIER CURRENT DRIVE REVERSAL - A drive current direction between first and second amplifiers can be selected using a received indication of an output current in an at least partially reactive load, and an amplified output signal can be produced using the selected drive current direction and the first and second amplifiers. Further, the first and second amplifiers can be configured to alternate between a pull-up mode and a pull-down mode, each amplifying half of a full wave output signal. | 01-07-2010 |
20110084746 | EDGE RATE CONTROL - This document discusses, among other things, a system and method for reducing electromagnetic interference of a switched signal. In an example, a switched input signal can be received at an input and a transition rate of an edge rate controlled, switched output signal can be controlled in response to the received switched input signal. | 04-14-2011 |
20120206191 | EDGE RATE CONTROL (ERC) PRE-BIASING TECHNIQUE - This document discusses, among other things, apparatus and methods for pre-biasing an edge rate controlled output stage of a switch circuit. In an example, a switch circuit can include an output transistor and a pre-bias circuit coupled to the output transistor. The pre-bias circuit can include a pre-bias transistor configured to selectively couple a control node of the output device to a first voltage, and wherein the pre-bias transistor can include a lower threshold voltage than the output transistor. | 08-16-2012 |
20120262211 | CLASS D PULSE WIDTH MODULATOR WITH DUAL FEEDBACK - This document discusses, among other things, a modulator including a first integrator configured to receive an input signal and a first feedback signal from an output stage, a second integrator configured to receive an output of the first integrator and a second feedback signal, and a comparator configured to be coupled to a regulated supply voltage, to receive an output of the second integrator and a modulation signal, and to provide a pulse width modulated representation of the input signal. The output stage is configured to be coupled to an unregulated supply voltage, and the second feedback signal can include a representation of an output of the comparator configured to reduce artifacts in the pulse width modulated representation of the input signal induced by changes in an amplitude of the unregulated supply voltage. | 10-18-2012 |
20120262230 | AMPLIFIER CROSSTALK CANCELLATION TECHNIQUE - This document discusses apparatus and methods for configuring and providing crosstalk cancellation to maintain channel separation in a multi channel system. In an example, an amplifier circuit can include a crosstalk cancellation circuit configured to reduce crosstalk from a first output to a second load and from a second output to a first load where the first load and the second load share a return path. | 10-18-2012 |
20130016844 | SUBSONIC TEST SIGNAL GENERATION TECHNIQUEAANM Llewellyn; William D.AACI San JoseAAST CAAACO USAAGP Llewellyn; William D. San Jose CA US - An apparatus includes a capacitor, a current generating circuit communicatively coupled to the capacitor, and a current pulse timing circuit communicatively coupled to the current source circuit. The current timing pulse circuit is configured to time durations of a first plurality of current pulses from the current generating circuit for charging the capacitor and a second plurality of current pulses for discharging the capacitor, and step the durations of the current pulses between a minimum duty cycle and a maximum duty cycle. A cycle of providing the first plurality of current pulses and providing the second plurality of current pulses results in generation of a subsonic pseudo-sinusoidal pulse signal at the capacitor. | 01-17-2013 |
20140126730 | METHODS AND APPARATUS RELATED TO PROTECTION OF A SPEAKER - 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 calibration parameter at the calibration temperature. | 05-08-2014 |
20150162834 | Dual-Mode Voltage Doubling Buck Converter With Smooth Mode Transition - Devices and methods provide a voltage regulating device including voltage supply circuitry configured to receive a first voltage, generate at least a second voltage based on the first voltage, and output an output voltage, the output voltage being one of the first voltage and the second voltage based on a voltage selection signal; regulator circuitry configured to switch between the output voltage and a reference potential based on a control signal; and control circuitry configured to generate the control signal, the control signal having a first duty cycle if the output voltage is the first voltage and a second duty cycle if the output voltage is the second voltage, the control circuitry configured to adjust the second duty cycle based on, at least in part, a droop voltage in the regulator circuitry. | 06-11-2015 |