Method and apparatus for a switch mode power supply that generates a high pulse width modulation gain while maintaining low noise sensitivity
Granted: May 6, 2008
Patent Number:
7369418
A power supply with high pulse width modulation gain and low noise sensitivity has been disclosed. In one embodiment, a power supply includes a regulator circuit controlling a power switch. The regulator circuit includes a control input that receives a current, which is the sum of a consumption current of the regulator and a feedback current. The consumption current of the regulator is varied as a function of the duty cycle of the power switch. The feedback current is the current in a…
Method and apparatus for substantially reducing electrical displacement current flow between input and output circuits coupled to input and output windings of an energy transfer element
Granted: May 6, 2008
Patent Number:
7369026
An energy transfer element with substantially reduced electrical displacement current flow between an input circuit coupled to the energy transfer element input winding and an output circuit coupled to the energy transfer element output winding. In one aspect, an energy transfer element includes an input winding, an output winding, an electrically conductive shield coupled to the input winding and a first cancellation winding coupled to the input winding. The electrically conductive…
Method and apparatus to improve regulation of a power supply
Granted: April 15, 2008
Patent Number:
7359222
Techniques are disclosed to regulate a power supply with a compensation signal generation circuit. One example regulated power supply includes a sense circuit coupled to sense an output voltage of the regulated power supply. The regulated power supply also includes a switching power converter circuit, which includes a switch coupled to be switched in response to a control signal received from the sense circuit to regulate the output voltage of the regulated power supply. The regulated…
Method and apparatus to limit output power in a switching power supply
Granted: April 15, 2008
Patent Number:
7359225
Techniques are disclosed to adjust a current limit in a switching regulator. One example switching regulator includes a switch to be coupled to an energy transfer element of a power supply. A controller to generate a drive signal is coupled to control switching of the switch to regulate an output of the power supply. A current limiter is included in the controller to adjust the drive signal to limit a current though the switch to a variable current limit value. The variable current limit…
Method and apparatus for substantially reducing electrical earth displacement current flow generated by wound components
Granted: April 8, 2008
Patent Number:
7355871
An energy transfer element having an energy transfer element input winding, an energy transfer element output winding and energy transfer element windings that reduce displacement currents. In one aspect, an energy transfer elements includes an energy transfer element core with first and second windings wound around the energy transfer element core. The first winding is capacitively coupled to the second winding. A third winding is wound around the energy transfer element core to…
Method and apparatus for extending the size of a transistor beyond one integrated circuit
Granted: April 1, 2008
Patent Number:
7352232
A technique for extending the size of a power transistor beyond one integrated circuit is disclosed. An example apparatus includes a first integrated circuit chip having a first switch, which includes first, second and third terminals. The first integrated circuit chip further includes a first driver circuit having an input and an output. The first integrated circuit chip also has a first control circuit coupled to output a first control signal. A second integrated circuit chip is…
Method for winding an energy transfer element core
Granted: March 25, 2008
Patent Number:
7346979
Methods for winding energy transfer element cores are disclosed. In one aspect, a method includes winding a plurality of layers of an input winding around an energy transfer element core. One layer of the input winding is wound with a number of turns different than a number of turns included in other layers of the input winding. An output winding is wound around the energy transfer element core with substantially the same number of turns as the number of turns of the one layer of the…
Method and apparatus for trimming current limit and frequency to maintain a constant maximum power
Granted: March 18, 2008
Patent Number:
7345462
A method which regulates a power supply is disclosed. In one aspect of the invention, the method includes sensing an excess control current through a control terminal with a control current sensor circuit. A transistor is switched with a control circuit in response to the control current sensor circuit and an oscillator that is coupled to a trim circuit, which is trimmed during manufacture of a circuit, to regulate the output of a power supply. A current through the transistor is limited…
High-voltage vertical transistor with a multi-gradient drain doping profile
Granted: February 26, 2008
Patent Number:
7335944
A high-voltage transistor includes first and second trenches that define a mesa in a semiconductor substrate. First and second field plate members are respectively disposed in the first and second trenches, with each of the first and second field plate members being separated from the mesa by a dielectric layer. The mesa includes a plurality of sections, each section having a substantially constant doping concentration gradient, the gradient of one section being at least 10% greater than…
Electronic circuit control element with tap element
Granted: February 19, 2008
Patent Number:
7333351
A technique for controlling a power supply with power supply control element with a tap element. In one embodiment, a power supply regulator includes a power transistor having first, second, third and fourth terminals. A control circuit is included, which is coupled to the third and fourth terminals of the power transistor. The power transistor is configured to switch a current between the first and second terminals in response a control signal received from the control circuit at the…
Method and apparatus to reduce maximum power from a power supply with transition region regulation
Granted: February 19, 2008
Patent Number:
7332900
Techniques are disclosed to regulate the output power of a power supply. An example regulator circuit includes a feedback circuit coupled to generate a feedback signal in response to an output of a power supply. The feedback circuit includes a voltage regulation circuit, a current regulation circuit and a transition region regulation circuit coupled to sense the output of the power supply and generate first, second and third regulation signals, respectively. The feedback signal is…
Methods for trimming electrical parameters in an electrical circuit
Granted: December 18, 2007
Patent Number:
7308754
Power supply switching regulator electrical circuit trimming methods. A trimming method includes assembling one or more components of a power supply switching regulator electrical circuit onto a printed circuit board having one or more electrical connections coupled to the said one or more components. An electrical parameter of the power supply switching regulator electrical circuit is then trimmed after the assembling of the one or more components of the power supply switching regulator…
Method and apparatus for sensing a current in a circuit
Granted: December 18, 2007
Patent Number:
7310048
Techniques are disclosed to sense a current in a circuit. For instance, current sense circuit according to the teachings of the present invention includes a current sense resistor coupled to an input of the current sense circuit. The current sense resistor is coupled to receive a current to be sensed from the input of the current sense circuit. The current to be sensed is converted to a current sense voltage. A first PN junction diode is coupled to the current sense resistor. A light…
Method and apparatus to improve frequency stability of an integrated circuit oscillator
Granted: December 4, 2007
Patent Number:
7304547
An apparatus providing a simple low cost integrated circuit oscillator with improved frequency stability over a range of selected frequencies by reducing the impact of process and temperature variations on a base current of bipolar transistor of the integrated circuit oscillator. A circuit includes a capacitor coupled to be alternatingly charged and discharged by first and second current sources. A first voltage follower circuit including a first bipolar transistor having a base is…
Methods and apparatus for maintaining an approximate constant current output characteristic in a switched mode power supply
Granted: November 27, 2007
Patent Number:
7301319
A regulator circuit maintaining an approximate constant current output characteristic. In one aspect, a disclosed regulator controls a switch that has a current limit threshold. A supply terminal and feedback terminal of the regulator are connected together as a control terminal such that a shunt regulator current is the control terminal current in excess of the internal supply current consumed by the regulator. The current limit threshold of the switch is changed as a function of the…
Method and apparatus for substantially reducing electrical earth displacement current flow generated by wound components
Granted: October 2, 2007
Patent Number:
7276999
An energy transfer element having windings. In one aspect, the energy transfer element includes a first winding wound around a core, the first winding has a first end and a second end. A second winding is wound around the core. The second winding has a first end and a second end. The first winding is capacitively coupled to the second winding to provide a transfer of energy from the first winding to the second winding. A third winding is wound around the core. The third winding has a…
Method and apparatus to control either a regulated or an unregulated output of a switching power supply
Granted: September 18, 2007
Patent Number:
7272025
Techniques are disclosed to control output power from a switching power supply. For example, a switching regulator according to aspects of the present invention includes a switch to be coupled to an energy transfer element of a power supply. A controller is coupled to the switch to control a switching of the switch to regulate an output voltage and an output current at an output of power supply output. A feedback circuit is coupled to the controller. The feedback circuit is coupled to…
Method of fabricating a high-voltage transistor with an extended drain structure
Granted: August 7, 2007
Patent Number:
7253042
A method for fabricating a high-voltage transistor with an extended drain region includes forming in a semiconductor substrate of a first conductivity type, first and second trenches that define a mesa having respective first and second sidewalls; then partially filling each of the trenches with a dielectric material that covers the first and second sidewalls. The remaining portions of the trenches are then filled with a conductive material to form first and second field plates. Source…
Method of forming an integrated circuit with multi-length power transistor segments
Granted: August 7, 2007
Patent Number:
7253059
A monolithic power integrated circuit fabricated on a semiconductor die includes a control circuit and a first output high voltage field-effect transistor (HVFET) having source and drain segments substantially equal to a first length. A second output HVFET has source and drain segments substantially equal to a second length. At least one of the first and second output HVFETs is coupled to the control circuit. It is emphasized that this abstract is provided to comply with the rules…
Method and apparatus providing a multi-function terminal for a power supply controller
Granted: August 7, 2007
Patent Number:
7253997
A power supply controller having a multi-function terminal. In one embodiment, a power supply controller for switched mode power supply includes a drain terminal, a source terminal, a control terminal and a multi-function terminal. The multi-function terminal may be configured in a plurality of ways providing any one or some of a plurality of functions including on/off control, external current limit adjustments, under-voltage detection, over-voltage detection and maximum duty cycle…