Asymmetric switch forward converter
Granted: May 14, 2013
Patent Number:
8441815
A switching circuit for use in a power supply includes a first active switch coupled to a first terminal of a primary winding of a transformer. A second active switch is coupled to a second terminal of the primary winding of the transformer. An output capacitance of the first active switch is greater than an output capacitance of the second active switch. A first passive switch is coupled to the second active switch and to the second terminal of the primary winding. A second passive…
Temperature independent reference circuit
Granted: May 14, 2013
Patent Number:
8441309
A temperature independent reference circuit includes first and second bipolar transistors with commonly coupled bases. First and second resistors are coupled in series between the emitter of the second bipolar transistor and ground. The first and second resistors have first and second resistance values, R1 and R2, and third and second temperature coefficients, TC3 and TC2, respectively. The resistance values being such that a temperature coefficient of a difference between the…
Method and apparatus for pulse width modulation
Granted: May 14, 2013
Patent Number:
8441293
An integrated control circuit according to aspects of the present invention includes an oscillator, a capacitor, and a logic gate. The oscillator generates a periodic timing signal that cycles between a first logic state for a first time duration and a second logic state for a second time duration. The capacitor receives a charge current in response to the periodic timing signal transitioning to the first logic state, where a voltage on the capacitor increases for the first time duration…
Method and apparatus for varying a duty cycle of a power supply controller responsive to multiple linear functions over a range of values of a feedforward signal
Granted: May 7, 2013
Patent Number:
8437154
An example power supply controller includes a switch duty cycle controller coupled to receive a feedback signal and a duty cycle adjust signal. The switch duty cycle controller is coupled to generate a drive signal coupled to control switching of a switch, which is coupled to an energy transfer element, to regulate energy delivered from an input of a power supply to an output of the power supply. The power supply controller also includes a gain selector circuit coupled to receive an…
Variable time clamp for a power supply controller
Granted: April 23, 2013
Patent Number:
8427848
An example integrated circuit for use in a power supply includes a feedback terminal and a controller having a variable time clamp (VTC). The feedback terminal is to be coupled to receive a feedback signal and the controller is to be coupled to enable or disable the conduction of a power switch during a switching cycle in response to the feedback signal. The controller includes a current limit comparator coupled to terminate the conduction of the power switch during an enabled switching…
Method and apparatus for maintaining a constant load current with line voltage in a switch mode power supply
Granted: April 23, 2013
Patent Number:
8427124
A method and apparatus of reducing peak current variation with changing input line voltage in a switch mode power supply is disclosed. An example method includes sensing a current through a switching device of the switch mode power supply. A variable current limit threshold is generated, which increases from a first level to a second level during an on time of the switching device. The current is compared to the variable current limit threshold. A feedback signal representative of an…
Power integrated circuit device with incorporated sense FET
Granted: April 23, 2013
Patent Number:
8426915
In one embodiment, a power integrated circuit device includes a main lateral high-voltage field-effect transistor (HVFET) and an adjacently-located lateral sense FET, both of which are formed on a high-resistivity substrate. A sense resistor is formed in a well region disposed in an area of the substrate between the HVFET and the sense FET. A parasitic substrate resistor is formed in parallel electrical connection with the sense resistor between the source regions of the HVFET and the…
Flyback converter with forward converter reset clamp
Granted: April 9, 2013
Patent Number:
8416586
A power supply includes a first power converter having a first transformer coupled to an input of the power supply and to a first output of the power supply. A clamp reset circuit is coupled to the first transformer. The clamp reset circuit includes a capacitor coupled to the first power converter and a Zener diode coupled to the capacitor. A second power converter is coupled to the clamp reset circuit. The second power converter includes a second transformer coupled to the clamp circuit…
Power system with shared clamp reset
Granted: April 9, 2013
Patent Number:
8416585
An example power supply includes a first power converter, a second power converter, and a shared clamp reset circuit. The first power converter is adapted to convert an input to a first output and includes a first transformer having a first primary winding. The second power converter is also adapted to convert the input to a second output and includes a second transformer having a second primary winding. The second primary winding of the second transformer is not the first primary…
Method and apparatus switching a semiconductor switch with a multi-stage drive circuit
Granted: April 2, 2013
Patent Number:
8410829
A multi-stage drive circuit is to be coupled to a semiconductor switch having a drive terminal, a first terminal and a second terminal, to switch the semiconductor switch on and off. The multi-stage drive circuit includes a first drive circuit, a second drive circuit and a selector circuit. The first drive circuit is to be coupled to provide a first drive signal to the drive terminal of the semiconductor switch and the second drive circuit is to be coupled to provide a second drive…
Checkerboarded high-voltage vertical transistor layout
Granted: April 2, 2013
Patent Number:
8410551
In one embodiment, a transistor fabricated on a semiconductor die includes a first section of transistor segments disposed in a first area of the semiconductor die, and a second section of transistor segments disposed in a second area of the semiconductor die adjacent the first area. Each of the transistor segments in the first and second sections includes a pillar of a semiconductor material that extends in a vertical direction. First and second dielectric regions are disposed on…
Method of fabricating a deep trench insulated gate bipolar transistor
Granted: April 2, 2013
Patent Number:
8410548
In one embodiment, a method comprises forming an epitaxial layer over a substrate of an opposite conductivity type, the epitaxial layer being separated by a buffer layer having a doping concentration that is substantially constant in a vertical direction down to the buffer layer. A pair of spaced-apart trenches is formed in the epitaxial layer from a top surface of the epitaxial layer down at least into the buffer layer. A dielectric material is formed in the trenches over the first and…
Method and apparatus for sensing multiple voltage values from a single terminal of a power converter controller
Granted: March 26, 2013
Patent Number:
8406013
An example controller for a power converter includes a switching control coupled to switch a power switch of the power converter to control a transfer of energy from an input of the power converter to an output of the power converter. A sensor is coupled to sample a single terminal of the controller during a portion of an off time of the power switch to output a signal representative of an output voltage of the power converter. The sensor is further coupled to sample the single terminal…
Power supply with input filter-controlled switch clamp circuit
Granted: March 19, 2013
Patent Number:
8400789
An example power supply in accordance with the teachings of the present disclosure includes a switch, an energy transfer element, a controller, an input filter, and a switch clamp circuit. The energy transfer element is coupled to the switch and the controller is coupled to control the switch to regulate an output of the power supply. The input filter is coupled to receive an input voltage of the power supply and includes a first input filter capacitor coupled to a node and a second…
VTS insulated gate bipolar transistor
Granted: March 19, 2013
Patent Number:
8399907
In one embodiment, a power transistor device comprises a substrate that forms a PN junction with an overlying buffer layer. The power transistor device further includes a first region, a drift region that adjoins a top surface of the buffer layer, and a body region. The body region separates the first region from the drift region. First and second dielectric regions respectively adjoin opposing lateral sidewall portions of the drift region. The dielectric regions extend in a vertical…
High-voltage vertical transistor with a varied width silicon pillar
Granted: March 12, 2013
Patent Number:
8395207
In one embodiment, a vertical HVFET includes a pillar of semiconductor material a pillar of semiconductor material arranged in a loop layout having at least two substantially parallel and substantially linear fillet sections each having a first width, and at least two rounded sections, the rounded sections having a second width narrower than the first width, a source region of a first conductivity type being disposed at or near a top surface of the pillar, and a body region of a second…
Method and apparatus for implementing an unregulated dormant mode with output reset in a power converter
Granted: February 26, 2013
Patent Number:
8385088
An implementation of an unregulated dormant mode with an output reset controller in a power converter is disclosed. An example method for controlling an output of a power converter includes generating a drive signal with a drive signal generator to regulate a flow of energy to one or more loads coupled to an output of the power converter in response to an energy requirement of the one or more loads. The drive signal generator is rendered dormant to cease for a first time period the…
Junction barrier schottky rectifiers having epitaxially grown P+-N methods of making
Granted: February 26, 2013
Patent Number:
8384182
A junction barrier Schottky (JBS) rectifier device and a method of making the device are described. The device comprises an epitaxially grown first n-type drift layer and p-type regions forming p+-n junctions and self-planarizing epitaxially over-grown second n-type drift regions between and, optionally, on top of the p-type regions. The device may include an edge termination structure such as an exposed or buried P+ guard ring, a regrown or implanted junction termination extension (JTE)…
Controller with punctuated switching control circuit
Granted: February 19, 2013
Patent Number:
8379420
An example controller for use in a power supply includes a zero crossing detection (ZCD) circuit and a punctuated switching control circuit. The ZCD circuit is coupled to generate a ZCD signal in response to a zero-crossing of an ac input voltage of the power supply. The punctuated switching control circuit is coupled to the ZCD circuit to generate a switching signal to control a switch to regulate an output of the power supply. The punctuated switching control circuit generates the…
Method and apparatus to regulate an output voltage of a power converter at light/no load conditions
Granted: February 12, 2013
Patent Number:
8374006
An example controller for a primary side control power converter includes a feedback circuit, a driver circuit, and an adjustable voltage reference circuit. The feedback circuit is coupled to compare a feedback signal representative of a bias winding voltage of the power converter with a voltage reference. The driver circuit is coupled to output a switching signal to control a switch of the power converter to regulate an output of the power converter in response the feedback circuit. The…
