Methods and apparatus for biasing a magnetic circuit to reduce audible noise from a switching power supply
Granted: February 15, 2022
Patent Number:
11250984
Presented herein are methods and apparatus for biasing magnetic circuits to reduce audible noise from a switching power supply. A magnetic component (e.g., a magnet) is constructed and provided to a core (e.g., a ferromagnetic core) to offset (i.e., bias) an applied magnetomotive force. By selecting and/or manufacturing the magnetic component based on a circuit operating condition, the offset may be tailored to advantageously shift a frequency of mechanical deformation outside the…
Controller for a semiconductor switch can include a transmitter and receiver that communicate across galvanic isolation using an inductive coupling
Granted: January 11, 2022
Patent Number:
11223391
A controller comprising a driver interface referenced to a first reference potential, a drive circuit referenced to a second reference potential, and an inductive coupling. The driver interface comprises a first receiver configured to compare a portion of signals having a first polarity on the first terminal of the inductive coupling with a first threshold, and a second receiver configured to compare a portion of signals having a second polarity on the second terminal of the inductive…
Method and apparatus for sequencing outputs in a multi-output power converter system
Granted: December 28, 2021
Patent Number:
11211870
Apparatus and methods for sequencing outputs in a multi-output power converter system are disclosed herein. During start-up multiple CC/CV outputs may be sequenced so that energy is first provided to a highest voltage secondary output and subsequently provided to a lowest voltage secondary output. Additionally, control may be exerted so as to concurrently and monotonically increase voltages during at least part of the start-up transient; and concurrent control may be further implemented…
Apparatus and methods for controlling a switch drive signal following mode transitions in a switching power converter
Granted: December 7, 2021
Patent Number:
11196347
A controller for use in a power converter that is configured to operate in a plurality of modes including a first mode and a second mode includes a frequency monitor module coupled to measure a signal characteristic of a switch drive signal coupled to control switching of a switches block of the power converter. The frequency monitor module includes a memory coupled to store a measured signal characteristic of the switch drive signal measured during the first mode. The frequency monitor…
Low common mode noise transformer structure with external float wire mount
Granted: November 2, 2021
Patent Number:
11164696
A transformer structure is disclosed to reduce common mode noise on an output load. The transformer structure includes a bobbin mounted on a magnetic core, a plurality of windings wound around the bobbin. The plurality of windings include a primary winding coupled to receive an input voltage, a secondary winding coupled to an output load; and a floating auxiliary winding located between the primary and secondary winding. The floating auxiliary winding includes a first terminal and a…
Gate stack for heterostructure device
Granted: September 7, 2021
Patent Number:
11114539
A heterostructure semiconductor device includes a first active layer and a second active layer disposed on the first active layer. A two-dimensional electron gas layer is formed between the first and second active layers. A sandwich gate dielectric layer structure is disposed on the second active layer. A passivation layer is disposed over the sandwich gate dielectric layer structure. A gate extends through the passivation layer to the sandwich gate dielectric layer structure. First and…
Method and apparatus for continuous conduction mode operation of a multi-output power converter
Granted: August 31, 2021
Patent Number:
11108331
Methods and apparatus for continuous conduction mode operation in multi-output power converters are described herein. During a switching cycle, secondary current may be delivered via a diode to a secondary output. Prior to beginning a subsequent switching cycle, a diverting current may be provided to a lower voltage secondary output on a parallel path. In this way diode current may be reduced to substantially zero prior to the subsequent switching cycle.
Signal amplifier with calibrated reference
Granted: August 17, 2021
Patent Number:
11095263
A signal amplifier for use in a power converter includes a variable reference generator coupled to generate a reference signal in response to a dimming control signal. A variable gain circuit is coupled to receive the reference signal, the gain signal, and a feedback signal representative of an output of the power converter. The variable gain circuit is coupled to output a first adjusted signal in response to the reference signal and the gain signal. The variable gain circuit is coupled…
Secondary controller for use in synchronous flyback converter
Granted: August 10, 2021
Patent Number:
11088621
A secondary controller for use in a power converter includes a drive circuit coupled to a secondary side of the power converter. The drive circuit is coupled to generate a first signal to enable a first switch coupled to a primary side of the primary converter. The first signal is generated in response to a feedback signal representative of an output of the power converter. A control circuit is coupled to receive the first signal and an input signal representative of a secondary winding…
Multi zone secondary burst modulation for resonant converters
Granted: August 3, 2021
Patent Number:
11081966
A power converter controller includes a control loop clock generator to generate a switching frequency signal responsive to a burst load threshold, a power signal, and a load signal. A switching frequency of the switching frequency signal is above a mechanical audio resonance range of an energy transfer element and above an audible noise frequency. A burst control circuit generates a burst on signal and a burst off signal in response to a feedback signal and a burst enable signal to…
Output-side controller with switching request at relaxation ring extremum
Granted: August 3, 2021
Patent Number:
11081964
A method of providing an input switching request signal to an input side switch includes determining a switching request window indicative of relaxation ringing during a first switching cycle. It is determined that the input side switch is operating in a discontinuous conduction mode (DCM) mode of operation during a second switching cycle. It is determined that the switching request window is open during the second switching cycle. The input switching request signal is enabled in…
Modulating jitter frequency as switching frequency approaches jitter frequency
Granted: August 3, 2021
Patent Number:
11079778
A controller for use in a power converter including a jitter generator circuit coupled to receive a drive signal from a switch controller and generate a jitter signal. The jitter signal is a modulated jitter signal when the drive signal is below a first threshold frequency. The switch controller is coupled to a power switch coupled to an energy transfer element. The switch controller is coupled to receive a current sense signal representative of a current through the power switch. The…
Protective insulator for HFET devices
Granted: July 27, 2021
Patent Number:
11075294
An HFET includes a first and second semiconductor material. A first composite passivation layer includes a first insulation layer and a first passivation layer, and the first passivation layer is disposed between the first insulation layer and the second semiconductor material. The HFET includes a second passivation layer, where the first insulation layer is disposed between the first passivation layer and the second passivation layer. A gate dielectric is disposed between the second…
Integrated resistor for semiconductor device
Granted: July 27, 2021
Patent Number:
11075196
A heterostructure semiconductor device includes first and second active areas, each electrically isolated from one another, and each including first and second active layers with an electrical charge disposed therebetween. A power transistor is formed in the first active area, and an integrated gate resistor is formed in the second active area. A gate array laterally extends over the first active area of the power transistor. First and second ohmic contacts are respectively disposed at…
Controller with frequency to on-time converter
Granted: June 22, 2021
Patent Number:
11043890
A controller for use in a power converter includes a secondary controller coupled to receive a feedback signal representative of an output of the power converter to generate d a request signal. A primary controller is coupled to receive the request signal to generate a primary drive signal. The primary drive signal is coupled to control switching of a power switch to control a transfer of energy from the input to the output of the power converter. A frequency to on-time converter…
Clamp for a hybrid switch
Granted: June 1, 2021
Patent Number:
11025249
A switch having a drain, a source, and a control. The switch comprising a depletion-mode transistor including a first, a second, and a control terminal and an enhancement-mode transistor including a first, a second, and a control terminal. The first terminal of the depletion-mode transistor is the drain of the switch and the control of the depletion-mode transistor is coupled to the source of the switch. The control of the enhancement-mode transistor is coupled to the control of the…
External adjustment of a drive control of a switch
Granted: May 4, 2021
Patent Number:
10998843
A control system to control a conductivity modulated device of a power switching array. The control system comprises a system controller to sense a power event and to output a command signal to adjust a drive characteristic of the conductivity modulated device in response to the sensed power event and a switch controller configured to receive the command signal and to control energy delivery to the load by controlling the turn on and turn off of the conductivity modulated device. The…
Idle ring detection for a multi-output power converter
Granted: March 30, 2021
Patent Number:
10965219
A controller for use in a power converter with multiple outputs includes a discharge detect circuit coupled to receive a voltage signal from a transformer winding of the power converter to output a discharge signal in response to the voltage signal. A multi-output signal process and interface block is coupled to output request signals to the output selection drive and idle ring visibility logic circuit. An output selection drive and idle ring visibility logic circuit is coupled to…
Active clamp circuit with steering network
Granted: March 30, 2021
Patent Number:
10965218
A power converter, comprising an energy transfer element, an output of the power converter, a power switch, an active clamp circuit, and a first controller. The active clamp circuit comprising a capacitance, a steering diode network coupled to the capacitance and configured to transfer a charge to the capacitance, a clamp switch coupled to the capacitance and configured to transfer the charge stored in the capacitance to the energy transfer element, and an offset element coupled to the…
Closed loop foldback control
Granted: March 16, 2021
Patent Number:
10951121
A controller for use in a power converter comprising a comparator, request control, and foldback control. The comparator configured to receive a feedback signal representative of an output of the power converter and a first regulation reference representative of a target value for the output, and in response to the comparison of the feedback signal and the first regulation reference, generate a first regulation signal. Request control configured to receive the first regulation reference,…
