Charles C Coles

US Patent:

6437638, Aug 20, 2002

Filed:

Nov 28, 2000

Appl. No.:

09/724854

Inventors:

Charles Coles - San Jose CA
Jon R. Roman - Boynton Beach FL

Assignee:

Micrel, Incorporated - San Jose CA

International Classification:

G06G 719

US Classification:

327540

Abstract:

The present invention provides an apparatus and method for regulating an output to stabilize the output without limiting an output current. The regulator includes a stabilizing circuit coupled to a source circuit and a sink circuit. The source circuit is configured to source the output current to the output, and the sink circuit is configured to sink the output current from the output. The stabilizing circuit is configured to transition the source circuit and the sink circuit between a conductive state and a nonconductive state to stabilize the output based on the voltage difference between the output and a reference voltage. The source and sink circuits each include at least one N-channel MOSFET transistor to source and sink output current. The stabilizing circuit includes a first and second amplifier, where the first amplifier couples with the sink circuit to transition the sink circuit between the conductive and nonconductive states, and the second amplifier coupled with the source circuit to transition the source circuit between the conductive and nonconductive states.

US Patent:

6552629, Apr 22, 2003

Filed:

Dec 12, 2000

Appl. No.:

09/735694

Inventors:

Jeffrey M. Dixon - Fremont CA
Charles Coles - San Jose CA
Andrew M. Cowell - San Jose CA

Assignee:

Micrel, Incorporated - San Jose CA

International Classification:

H03H 703

US Classification:

333172, 333175, 333181

Abstract:

In accordance with the teachings of this invention a novel method and apparatus is taught which provides for the stabilizing of an output signal through an output circuit having a compensation circuit coupled with an output capacitor, such that the compensation circuit is configured to compensate for an equivalent series resistance of the output capacitor. The compensation circuit compensates for the equivalent series resistance by providing a shift in a phase of the output signal to stabilize the output signal. The shift in phase is accomplished through the addition of a second zero at a second zero frequency to stabilize the output signal. The second zero is added such that the second zero frequency is closer to a first pole frequency than a first zero frequency, where the first pole frequency is proportional to the equivalent series resistance and the first zero is proportional to the output capacitor. The compensation circuit includes at least a compensation inductor and a compensation resistor, and the output capacitor is a ceramic capacitor.

US Patent:

8350546, Jan 8, 2013

Filed:

Oct 31, 2007

Appl. No.:

11/933402

Inventors:

Richard K. Williams - Cupertino CA, US
Kevin D'Angelo - Santa Clara CA, US
Charles Coles - Milpitas CA, US

Assignee:

Advanced Analogic Technologies, Inc. - Santa Clara CA

International Classification:

G05F 1/10
G05F 1/652
G05F 1/44

US Classification:

323282, 323284, 323222, 323226

Abstract:

A SEPIC converter with over-voltage protection includes a high-side inductor that connects a node Vto a node V. The node Vis connected, in turn to ground by a power MOSFET. The node Vis also connected to a node Vby a first capacitor. The node Vis connected to ground by a low-side inductor. A rectifier diode further connects the node Vand a node Vand an output capacitor is connected between the node Vand ground. A PWM control circuit is connected to drive the power MOSFET. An over-voltage protection MOSFET connects an input supply to the PWM control circuit and the node V. A comparator monitors the voltage of the input supply. If that voltage exceeds a predetermined value Vthe comparator output causes the over-voltage protection MOSFET to disconnect the node Vand the PWM control circuit from the input supply.

US Patent:

20090102440, Apr 23, 2009

Filed:

Oct 23, 2007

Appl. No.:

11/877363

Inventors:

Charles Coles - Milpitas CA, US

Assignee:

Advanced Analogic Technologies, Inc. - Sunnyvale CA

International Classification:

G05F 1/10

US Classification:

323271

Abstract:

A buck-boost switching regulator includes two buck switches and two boost switches. Two ramp voltages VY and VY are generated. The voltage VY is compared to a voltage VEA that is proportional to the output of the switching regulator. This defines the duty cycle of the two buck switches. The voltage VX is compared to a voltage VEA that is inversely proportional to the output of the switching regulator. This defines the duty cycle of the two boost switches. The regulator seamlessly transitions between Buck, Boost and Buck-Boost modes depending on input and output conditions.

US Patent:

20130119955, May 16, 2013

Filed:

Jan 7, 2013

Appl. No.:

13/735940

Inventors:

Richard K. Williams - Cupertino CA, US
Kevin D'Angelo - Santa Clara CA, US
Charles Coles - Milpitas CA, US

Assignee:

Advanced Analogic Technologies Inc. - Santa Clara CA

International Classification:

H02H 3/20
G05F 1/46

US Classification:

323282

Abstract:

A SEPIC converter with over-voltage protection includes a high-side inductor that connects a node Vto a node V. The node Vis connected, in turn to ground by a power MOSFET. The node Vis also connected to a node Vby a first capacitor. The node Vis connected to ground by a low-side inductor. A rectifier diode further connects the node Vand a node Vand an output capacitor is connected between the node Vand ground. A PWM control circuit is connected to drive the power MOSFET. An over-voltage protection MOSFET connects an input supply to the PWM control circuit and the node V. A comparator monitors the voltage of the input supply. If that voltage exceeds a predetermined value Vref the comparator output causes the over-voltage protection MOSFET to disconnect the node Vand the PWM control circuit from the input supply.