Philip Robert Cooke

US Patent:

6366070, Apr 2, 2002

Filed:

Jul 12, 2001

Appl. No.:

09/903942

Inventors:

Philip R. Cooke - San Jose CA
Richard Redl - Farvagny-le-Petit, CH

Assignee:

Analog Devices, Inc. - Norwood MA

International Classification:

G05F 144

US Classification:

323284, 323285, 323222

Abstract:

A switching voltage regulator employs a âdual modulationâ scheme to control the regulators switching components. A control circuit indirectly monitors load current. When the load decreases, the control circuit reduces both the duty ratio and the frequency of the control signals which operate the switching transistors, thereby maintaining a high efficiency level over a wider output current range than can be achieved with fixed-frequency control signals. In a preferred embodiment, the regulator employs three operating modes. For heavy loads, the switching components are operated at a constant frequency. For moderate-to-light loads, the dual modulation control scheme is used. For light loads, the regulator enters a âpulse-skippingâ mode which can achieve very low operating frequencies to further improve efficiency. The invention may be used with switching regulators using peak current mode, average current mode, or voltage mode control, as well as buck, buck-boost, and boost power stages.

US Patent:

7772904, Aug 10, 2010

Filed:

Feb 16, 2009

Appl. No.:

12/371799

Inventors:

Philip Cooke - Raleigh NC, US

Assignee:

Infineon Technologies AG - Neubiberg

International Classification:

H03K 3/017

US Classification:

327175

Abstract:

According to an embodiment, a mixed signal controller includes a fine controller, a coarse controller and a digital controller. The fine controller is operable to output an analog modulation signal responsive to an analog control signal and a voltage signal input to the fine controller. The coarse controller is operable to output a digital pulse width modulation (PWM) signal responsive to the analog modulation signal and an analog PWM reference signal input to the coarse controller. The digital controller is operable to program the analog control signal and the analog PWM reference signal responsive to the digital PWM signal so that the fine and coarse controllers together regulate the voltage signal at a predetermined voltage level.

US Patent:

57106975, Jan 20, 1998

Filed:

Mar 26, 1996

Appl. No.:

8/622009

Inventors:

Philip R. Cooke - Nashua NH
John R. Wiggenhorn - Cary NC

Assignee:

Unitrode Corporation - Merrimack NH

International Classification:

H02M 3335

US Classification:

363 21

Abstract:

A power supply controller implementing frequency foldback and volt-second duty cycle clamp features. An oscillator timing capacitor is charged with a fixed current and is discharged with a fixed current when the output voltage is above a predetermined level and with a decreasing current when the output voltage falls below the predetermined level, so as to decrease the power supply operating frequency during short circuit or overload fault conditions. A volt-second duty cycle clamp circuit limits the duty cycle to a maximum value which is independent of the tolerance of a capacitor which sets the maximum duty cycle as a function of the power supply input voltage.

US Patent:

59694980, Oct 19, 1999

Filed:

Nov 19, 1997

Appl. No.:

8/971874

Inventors:

Philip Cooke - Nashua NH

Assignee:

Unitrode Corporation - Merrimack NH

International Classification:

H02P 742

US Classification:

318799

Abstract:

A controller for variable speed three-phase AC squirrel-cage induction motors in accordance with a volts-per-hertz control method is disclosed. Direct current ("DC") link current is employed to compensate for rotor slip. In particular, rotor slip is estimated and added to a speed reference command to compensate for changing loads. A direction input and speed reference command provide complete control over the induction motor.