Variable feedback signal based on conduction time
Granted: October 18, 2016
Patent Number:
9473031
A controller for a power converter includes conduction detection circuitry and a variable reference generator. The conduction detection circuitry is coupled to generate a conduction signal representative of conduction times that an input signal is above a threshold value. The variable reference generator is coupled to receive the conduction signal and configured to generate a count value in response to a first conduction time of the conduction signal. The variable reference generator is…
Deposit/etch for tapered oxide
Granted: October 18, 2016
Patent Number:
9472630
A process for fabricating a tapered field plate dielectric for high-voltage semiconductor devices is disclosed. The process may include depositing a thin layer of oxide, depositing a polysilicon hard mask, depositing a resist layer and etching a trench area, performing deep silicon trench etch, and stripping the resist layer. The process may further include repeated steps of depositing a layer of oxide and anisotropic etching of the oxide to form a tapered wall within the trench. The…
Controller IC with zero-crossing detector and capacitor discharge switching element
Granted: September 27, 2016
Patent Number:
9455621
An integrated circuit (IC) for controlling the discharge of a capacitor coupled across first and second input terminals of a power converter circuit, wherein the first and second terminals for receiving an ac line voltage. The IC includes a switching element coupled across the first and second input terminals and a detector circuit. The detector circuit including first and second comparators that produce first and second output signals responsive to a zero-crossing event of the ac line…
Load responsive jitter
Granted: September 20, 2016
Patent Number:
9450478
A controller for a power converter that may sense whether the power converter is in a light load condition. If the power converter is a light load condition, the switching frequency may be within the audible noise range. Once the controller senses the light load condition, the controller may modulate the switching frequency of the power switch such that the switching frequency is no longer within the audible noise range. The controller comprises of a current limit generator coupled to…
Active reduced voltage switching using secondary switch
Granted: September 13, 2016
Patent Number:
9444357
A controller includes a primary controller and a secondary controller to control switching of a power switch and a secondary switch, respectively, coupled to an energy transfer element of a power converter. A first drive circuit is coupled to generate a first drive signal to enable a first ON section of the secondary drive signal after an ON section of the primary drive signal. A second drive circuit is coupled to generate a second drive signal to enable a second ON section of the…
USB charging with data communication
Granted: September 13, 2016
Patent Number:
9444278
A process is disclosed for communicating digital data between a powered device and a charging device via a universal serial bus (USB). The process includes conducting a handshaking period between the powered device and the charging device via the USB. The powered device initiates a mode of normal operation of the charging device after an end of the handshaking period. The charging device communicates digital data (e.g., available power levels) between the powered device and the charging…
Phase angle detection module for power converter
Granted: September 6, 2016
Patent Number:
9438122
A power converter controller asserts a leading edge signal when a leading edge of a voltage signal is detected. The voltage sense signal is representative of an input voltage of the power converter. A trailing edge signal is asserted when a trailing edge of the voltage signal is detected. A first state of a threshold signal is generated when the voltage sense signal is at or above an upper threshold and generating a second state of the threshold signal when the voltage sense signal is at…
High-quality GaN high-voltage HFETs on silicon
Granted: September 6, 2016
Patent Number:
9437688
A GaN HFET includes a silicon substrate with an Al2O3 layer above the silicon substrate. The Al2O3 layer has voids formed therein. A plurality of alternating GaN and AlN layers are above the Al2O3 layer. The GaN and AlN layers are under continuous compressive stress.
Static discharge system
Granted: August 23, 2016
Patent Number:
9425195
A semiconductor circuit includes a three-terminal high voltage semiconductor device, a charge distribution structure and a static discharge system. The charge distribution structure has a plurality of conductors with a floating potential. The charge distribution structure is capacitively coupled to a first terminal of the semiconductor device. The static discharge system removes charge that accumulates on at least a subset of the conductors. The static discharge system removes the charge…
Trailing edge detector using current collapse
Granted: August 16, 2016
Patent Number:
9419528
A controller for a power converter includes an edge detection circuit including a first circuit coupled to coupled to compare a voltage sense signal representative of an input voltage to a first reference, and a second circuit coupled to compare a current sense signal representative of an input current to a second reference. A slope sense circuit is coupled to measure a slope of the voltage sense signal over time. An edge driver circuit is coupled to generate an edge signal that…
Dimmer detector for bleeder circuit activation
Granted: August 2, 2016
Patent Number:
9408261
A circuit to be utilized for an LED driver bleeder activation. The circuit comprises a circuit block for timing a duration of any removed portion of a rectified line signal. The input of the circuit to be coupled to receive the phase controlled rectified line signal through a voltage divider. Comparing the divided rectified line signal with a threshold voltage and output a comparison result. A timer coupled to the comparator and responsive to the comparison result to time the duration of…
Multi-bleeder mode control for improved LED driver performance
Granted: July 26, 2016
Patent Number:
9402293
Various examples directed to phase-dimming LED driver input circuitry having multiple bleeder circuits activated by a controller with multi-bleeder mode control are disclosed. In one example, the input circuitry may include multiple bleeder circuits controlled by the controller in an open-loop or closed-loop configuration. The controller may selectively activate or deactivate the multiple bleeder circuits based on the input line voltage, the dimming state, and the type of dimming being…
Monolithic AC/DC converter for generating DC supply voltage
Granted: July 26, 2016
Patent Number:
9401660
An integrated circuit (IC) comprises a rectifier/regulator circuit coupled to receive an ac source voltage and output a regulated dc voltage. The rectifier/regulator circuit includes first and second switching elements that provide charging current when enabled. The first and second switching elements do not provide charging current when disabled. A sensor circuit is coupled to sense the regulated dc voltage and generate a feedback control signal coupled to the rectifier/regulator…
Input voltage sensor responsive to load conditions
Granted: July 26, 2016
Patent Number:
9401657
A power converter controller includes a switch driver circuit coupled to generate a drive signal to control switching of a power switch to control a transfer of energy from an input of the power converter to an output of the power converter. An input sense circuit is coupled to receive an input sense signal representative of the input of a power converter. A sense enable circuit is coupled to receive the drive signal to generate a sense enable signal to control the input sense circuit in…
Saturation prevention in an energy transfer element of a power converter
Granted: July 26, 2016
Patent Number:
9401634
A controller for use in a power converter includes logic circuits to turn on and off a switch to regulate an output quantity. A first integrating capacitor is charged with a combination of a first current and a second current while the switch is turned on. The first current is proportional to a reset voltage and the second current is proportional to an input voltage. A reference generation circuit including a second integrating capacitor is charged with the first current during a…
Controller for a power supply with transition region regulation
Granted: July 19, 2016
Patent Number:
9397560
A method for regulating a flow of energy from an input to an output of a power converter includes receiving a first signal representative of an output voltage, and receiving a second signal representative of a current of the power converter. An output current of the power converter is determined in response to at least one of the first and second signals. A power switch of the power converter is switched to regulate the output current of the power converter to a substantially constant…
Controller with constant current limit
Granted: July 12, 2016
Patent Number:
9391523
Methods and apparatuses are disclosed for generating a temperature independent current limit. The value of the temperature independent current limit may be determined based in part on an error signal representative of a difference between an actual output value and a desired output value of a power converter. When the error signal is below a lower threshold voltage, the temperature independent current limit may be set to a first value. When the error signal is above an upper threshold…
Secondary controller for use in synchronous flyback converter
Granted: June 21, 2016
Patent Number:
9374011
A secondary controller for use in a synchronous flyback converter includes a comparator, a drive circuit, and logic circuitry. The comparator is coupled to generate a compare signal in response to a comparison of a threshold to an input signal representative of a secondary winding voltage of the synchronous flyback converter. The drive circuit is coupled to generate a drive signal to control a first switch to be coupled to a primary side of the synchronous flyback converter. The drive…
Overvoltage protection circuit
Granted: June 14, 2016
Patent Number:
9368961
Apparatus and methods for generating an overvoltage signal from a bias winding signal of a power converter transformer are disclosed. In one example, an overvoltage protection circuit may include a current augmentation circuit and a detection circuit. The current augmentation circuit may be coupled to receive the bias winding signal, which may be representative of the power converter output. The current augmentation circuit may include a threshold circuit and a filter circuit that may…
Dimming edge detection for power converter
Granted: June 14, 2016
Patent Number:
9369048
A controller for a power converter includes an edge detection circuit and a drive circuit. The edge detection circuit includes a comparator, a count module, and an edge checking module. The comparator is coupled to output a compare signal in response to comparing an input sense signal and a count signal. The input sense signal is representative of an input voltage of the power converter. The count module is coupled to adjust the count signal to track the input sense signal in response to…
