High-voltage lateral transistor with a multi-layered extended drain structure
Granted: September 28, 2004
Patent Number:
6798020
A high-voltage transistor with a low specific on-state resistance and that supports high voltage in the off-state includes one or more source regions disposed adjacent to a multi-layered extended drain structure which comprises extended drift regions separated from field plate members by one or more dielectric layers. With the field plate members at the lowest circuit potential, the transistor supports high voltages applied to the drain in the off-state. The layered structure may be…
Method and apparatus for sensing current and voltage in circuits with voltage across an LED
Granted: September 21, 2004
Patent Number:
6795321
Methods and apparatuses to sense current and voltage in circuits with voltage drop. A sense circuit includes a series combination of a diode and a resistor in the path of the current to be sensed, the voltage across this series combination coupled to drive a light emitting diode (LED).
Method of making a high-voltage transistor with buried conduction regions
Granted: September 7, 2004
Patent Number:
6787437
A high voltage insulated gate field-effect transistor includes an insulated gate field-effect device structure having a source and a drain, the drain being formed with an extended well region having one or more buried layers of opposite conduction type sandwiched therein. The one or more buried layers create an associated plurality of parallel JFET conduction channels in the extended portion of the well region. The parallel JFET conduction channels provide the HVFET with a low on-state…
High-voltage vertical transistor with a multi-layered extended drain structure
Granted: September 7, 2004
Patent Number:
6787847
A high-voltage transistor with a low specific on-state resistance and that supports high voltage in the off-state includes one or more source regions disposed adjacent to a multi-layered extended drain structure which comprises extended drift regions separated from field plate members by one or more dielectric layers. With the field plate members at the lowest circuit potential, the transistor supports high voltages applied to the drain in the off-state. The layered structure may be…
Method and apparatus for reducing audio noise in a switching regulator
Granted: August 31, 2004
Patent Number:
6784646
A switching regulator utilizing on/off control that reduces audio noise at light loads by adjusting the current limit of the switching regulator. In one embodiment, a switching regulator includes a state machine that adjusts the current limit of the switching regulator based on a pattern of feedback signal values from the output of the power supply for a preceding N cycles of the drive signal. The state machine adjusts the current limit lower at light loads such that cycles are not…
High-voltage vertical transistor with a multi-layered extended drain structure
Granted: August 24, 2004
Patent Number:
6781198
A high-voltage transistor with a low specific on-state resistance and that supports high voltage in the off-state includes one or more source regions disposed adjacent to a multi-layered extended drain structure which comprises extended drift regions separated from field plate members by one or more dielectric layers. With the field plate members at the lowest circuit potential, the transistor supports high voltages applied to the drain in the off-state. The layered structure may be…
Method and apparatus for maintaining a constant load current with line voltage in a switch mode power supply
Granted: August 24, 2004
Patent Number:
6781357
A power supply including a regulation circuit that maintains an approximately constant load current with line voltage. In one embodiment, a regulation circuit includes a semiconductor switch and current sense circuitry to sense the current in the semiconductor switch. The current sense circuitry has a current limit threshold. The regulation circuit current limit threshold is varied from a first level to a second level during the time when the semiconductor switch is on. One embodiment of…
High-voltage transistor with multi-layer conduction region
Granted: August 17, 2004
Patent Number:
6777749
A high voltage insulated gate field-effect transistor includes an insulated gate field-effect device structure having a source and a drain, the drain being formed with an extended well region having one or more buried layers of opposite conduction type sandwiched therein. The one or more buried layers create an associated plurality of parallel JFET conduction channels in the extended portion of the well region. The parallel JFET conduction channels provide the HVFET with a low on-state…
Method and apparatus for output voltage regulation in primary controlled switched mode power supplies
Granted: August 10, 2004
Patent Number:
6775155
A voltage sense circuit and power supply regulation technique. In one aspect, a voltage sense circuit utilized in a power supply regulator includes a transformer including a sense winding and an output winding. A first diode is coupled to the sense winding, a first resistor is coupled to the first diode and a first capacitor coupled to the first resistor and the first diode. A second diode coupled to the first capacitor, the first resistor and the first diode. A second capacitor coupled…
High-voltage transistor with multi-layer conduction region
Granted: July 27, 2004
Patent Number:
6768172
A high voltage insulated gate field-effect transistor includes an insulated gate field-effect device structure having a source and a drain, the drain being formed with an extended well region having one or more buried layers of opposite conduction type sandwiched therein. The one or more buried layers create an associated plurality of parallel JFET conduction channels in the extended portion of the well region. The parallel JFET conduction channels provide the HVFET with a low on-state…
High-voltage transistor with JFET conduction channels
Granted: July 27, 2004
Patent Number:
6768171
A high voltage insulated gate field-effect transistor with multiple JFET conduction channels comprises a first buried layer disposed in a first epitaxial layer formed on a substrate, a second buried layer disposed in a second epitaxial layer formed on the first epitaxial layer, with the first and second buried layers being spaced vertically apart in a substantially parallel configuration such that a JFET conduction channel of the first conductivity type is formed between the first and…
Method and apparatus for substantially reducing electrical earth displacement current flow generated by wound components
Granted: July 13, 2004
Patent Number:
6762946
An energy transfer element having an energy transfer element input winding and an energy transfer element output winding. In one aspect, the energy transfer element input winding is capacitively coupled to the energy transfer element output winding. The energy transfer element is capacitively coupled to electrical earth. One or more additional windings are introduced as part of the energy transfer element. The one or more additional windings substantially reduce capacitive displacement…
Method of fabricating a high-voltage transistor
Granted: July 6, 2004
Patent Number:
6759289
A method for making a high voltage insulated gate field-effect transistor with multiple JFET conduction channels comprises successively implanting a dopant of a first conductivity type in a first substrate of a second conductivity type so as to form a first plurality of buried layers disposed at a different vertical depths. The first substrate is flipped over and then bonded to a second substrate of the first conductivity type. After the first substrate has been thinned, another set of…
Switched mode power supply responsive to current derived from voltage across energy transfer element input
Granted: June 22, 2004
Patent Number:
6754089
A switched mode power supply having a regulated reflected voltage. In one embodiment, a switched mode power supply includes a power supply regulator coupled between a positive input supply rail of the power supply and a primary winding of an energy transfer element. The reflected voltage across the primary winding of the transfer element is related to the output voltage across a secondary winding of the energy transfer element according to the turns ratio of the energy transfer element.…
Method of fabricating a high-voltage transistor with a multi-layered extended drain structure
Granted: June 15, 2004
Patent Number:
6750105
A method for fabricating a high-voltage transistor with an extended drain region includes forming an epitaxial layer on a substrate, the epitaxial layer and the substrate being of a first conductivity type; then etching the epitaxial layer to form a pair of spaced-apart trenches that define first and second sidewall portions of the epitaxial layer. A dielectric layer is formed that partially fills each of the trenches, covering the first and second sidewall portions. The remaining…
Method and apparatus providing final test and trimming for a power supply controller
Granted: June 15, 2004
Patent Number:
6750640
A power supply controller having final test and trim circuitry. In one embodiment, a power supply controller for switched mode power supply includes a selector circuit, a trim circuit, a shutdown circuit and a disable circuit. The trim circuit includes a programmable circuit connection that can be selected by the selector circuit by toggling a voltage on an external terminal such as for example a power supply terminal, a control terminal or a function terminal of the power supply…
Method and apparatus for trimming current limit and frequency to maintain a constant maximum power
Granted: June 8, 2004
Patent Number:
6747443
Methods and apparatuses to trim current limit (Ip) and frequency (f) to maintain a constant maximum power. In one aspect of the invention, a power supply regulator having a peak current limit detection threshold and an operating frequency is disclosed. The peak current limit threshold or the operating frequency are adjusted specifically to maintain the Ipm·fn product substantially constant from one power supply controller to another where m is substantially equal to 2 and n is…
Off-line converter with digital control
Granted: June 8, 2004
Patent Number:
6747444
A DC to DC converter comprising an energy storage element comprising an energy storage element input and an energy storage element output, the energy storage element input coupled to receive a first power level and the energy storage element output providing a second power level. The converter also comprises a feedback circuit comprising a feedback input and a feedback output, the feedback input coupled to the energy storage element output. The converter further comprises a regulator…
Output feedback and under-voltage detection system
Granted: June 1, 2004
Patent Number:
6744645
A switched mode controller for properly handling an under-voltage condition in a power line which includes a current mirror for receiving current from the power line; a reference current source coupled to the current mirror for supplying a reference current; and a power transistor coupled to the reference current source, the power transistor generating a pulse width modulated signal when current from the power line exceeds the reference current, the power transistor being disabled when…
Method and apparatus for balancing active capacitor leakage current
Granted: May 18, 2004
Patent Number:
6738277
A circuit that provides a method and apparatus to actively balance capacitor leakage current from series stacked capacitors and disconnects itself when stacked capacitors are configured for doubler operation. In one embodiment, the active circuit includes high voltage low current transistors, such as for example a PNP bipolar transistor and an NPN bipolar transistor, that are configured in a sink-source voltage follower arrangement with the bases of the transistors connected to a voltage…
