Michael E Broach

US Patent:

6806695, Oct 19, 2004

Filed:

Mar 31, 2003

Appl. No.:

10/404225

Inventors:

Michael Eugene Broach - San Mateo CA
Barry James Culpepper - Sunnyvale CA

Assignee:

National Semiconductor Corporation - Santa Clara CA

International Classification:

H03K 2100

US Classification:

323513

Abstract:

Optimization of a parameter can be achieved by a servo loop having a temperature sensor, a temperature change detector, and a parameter adjuster. The temperature sensor monitors the temperature of an electronic device while the parameter is varied. The temperature change detector detects whether the electronic device temperature is increasing or decreasing. The parameter has a value associated with minimum power consumption when the monitored temperature reaches a minimum. The parameter is adjusted dynamically to a new preferred value as operating conditions of the electronic device change.

US Patent:

6934779, Aug 23, 2005

Filed:

Apr 21, 2003

Appl. No.:

10/420996

Inventors:

Michael Eugene Broach - San Mateo CA, US

Assignee:

National Semiconductor Corporation - Santa Clara CA

International Classification:

G06F013/12

US Classification:

710 69, 341155

Abstract:

An integrated circuit is configured to receive encoded digital data from a system controller over a single signal line. The system controller encodes the digital data into a singular analog quantity such as a voltage, a current, a sine wave frequency, a sine wave amplitude, a pulse train frequency, or a pulse train duty cycle. The encoded digital data is transmitted to the signal line. The integrated circuit decodes the digital data from the signal line. The decoded digital data is employed by the integrated circuit to adjust one or more parameters of the integrated circuit. In one example, one or more parameters may be adjusted to select various operating modes for the integrated circuit. The singular analog quantity encoding/decoding methodology may be extended to more than one signal line when desirable.

US Patent:

6952093, Oct 4, 2005

Filed:

Feb 17, 2004

Appl. No.:

10/780207

Inventors:

Michael Eugene Broach - San Mateo CA, US
Frank John De Stasi - San Leandro CA, US

Assignee:

National Semiconductor Corporation - Santa Clara CA

International Classification:

G01R001/04
G01R027/28
G05F001/40

US Classification:

3241581, 324654, 323282

Abstract:

A system, method, and apparatus are arranged to provide small-signal compensation in a switching regulator that includes an inductor. A zero adjustment circuit is included in the system to introduce at least one zero in the closed-loop transfer function associated with the regulator. The zero adjustment circuit is responsive to a measurement signal, which is associated with one or more measured parameters associated with the inductor. By changing the location of at least one zero in response to the measurement signal it is possible to dynamically change the compensation based on variations in the inductance of the inductor. The zero adjustment circuit may be provided as a portion of the controller block of the regulator, or as a separate feedback circuit. The zero adjustment circuit can be implemented digitally as a portion of a DSP block, or as an analog function as may be desired in a particular system.

US Patent:

6969976, Nov 29, 2005

Filed:

Jun 4, 2004

Appl. No.:

10/861872

Inventors:

Michael Eugene Broach - San Mateo CA, US
Frank John De Stasi - San Leandro CA, US

Assignee:

National Semiconductor Corporation - Santa Clara CA

International Classification:

G05F001/10
G05F001/656

US Classification:

323222, 323284, 323901

Abstract:

A system, method, and apparatus are arranged to provide for current limit adjustments in a switching regulator that includes an inductor. A switched voltage divider circuit is selectively activated according to the actuation of various switching circuits in the regulator. The output of the switched voltage divider circuit is compared to a reference signal from a reference circuit to determine when a current limit is reached. At least one of the voltage divider ratio and the reference signal is adjustable in response to measurements related to the inductor saturation such that the current limit is changed to match inductor characteristics.

US Patent:

7000128, Feb 14, 2006

Filed:

Dec 30, 2002

Appl. No.:

10/334691

Inventors:

Michael Eugene Broach - San Mateo CA, US

Assignee:

National Semiconductor Corporation - Santa Clara CA

International Classification:

G06F 1/26

US Classification:

713320, 713300, 323271, 323275, 323283, 323285, 327108, 327109

Abstract:

The present invention increases power efficiency in power FET applications with varying loads. A constant frequency mode can be used without detracting from efficiency. This is accomplished by reducing repetitive gate charge power losses. The present invention controls the channel impedance of the FET using a timed tri-state driver to drive a level of charge associated with the gate of the FET that is appropriate to the load requirements. When the voltage level at the FET gate reaches the appropriate level, the driver is tri-stated, so that the gate does not continue to charge.

US Patent:

7042207, May 9, 2006

Filed:

Nov 7, 2003

Appl. No.:

10/703960

Inventors:

Michael Eugene Broach - San Mateo CA, US

Assignee:

National Semiconductor Corporation - Santa Clara CA

International Classification:

G01R 15/18

US Classification:

324117R

Abstract:

A system and method measures parameters associated with an inductor such as in a switching converter. The inductance value can be determined by monitoring voltages and currents associated with the inductor when a measurement mode is activated. In one example, the measurement is provided by a signal processing system that includes an analog differentiator. In another example, the measurement is provided by a signal processing system that converts the analog measurement voltages into digital quantities that are analyzed in the digital domain. The value of the inductance value is determined by calculating of ΔVand ΔI/Δt. The saturation point in the inductance is located by measuring the change in slew rate of the inductance during the measurement mode. Average values for the inductor and the slew rate can be determined using digital techniques. Other parameters such as current limit and on-time of the inductor can be adjusted by this methodology.

US Patent:

7265530, Sep 4, 2007

Filed:

Feb 17, 2004

Appl. No.:

10/780375

Inventors:

Michael Eugene Broach - San Mateo CA, US
Frank John De Stasi - San Leadro CA, US

Assignee:

National Semiconductor Corporation - Santa Clara CA

International Classification:

G01R 15/20

US Classification:

324117R

Abstract:

A system, method, and apparatus are arranged to provide adaptive slope compensation in a switching regulator that includes an inductor. A control loop of the switching regulator is responsive to a ramp signal. A ramp generator that includes a capacitor circuit and a current source provides the ramp signal, where at least one of the current level of the current source and the value of the capacitor circuit are adjusted to vary the slope of the ramp signal. The adjustment of the ramp signal is responsive to at least one of: a set point for the output voltage of the switching regulator, a feedback voltage that is related to the output voltage, and a measured parameter associated with the inductor in the switching regulator. By dynamically adjusting the slope of the ramp signal, slope compensation is provided for a range of inductor values that can dynamically change during operation.

US Patent:

7307412, Dec 11, 2007

Filed:

Mar 10, 2006

Appl. No.:

11/372567

Inventors:

Michael Eugene Broach - San Mateo CA, US

Assignee:

National Semiconductor Corporation - Santa Clara CA

International Classification:

G01R 15/18

US Classification:

324117R

Abstract:

A system and method measures parameters associated with an inductor such as in a switching converter. The inductance value can be determined by monitoring voltages and currents associated with the inductor when a measurement mode is activated. In one example, the measurement is provided by a signal processing system that includes an analog differentiator. In another example, the measurement is provided by a signal processing system that converts the analog measurement voltages into digital quantities that are analyzed in the digital domain. The value of the inductance value is determined by calculating of ΔVand ΔI/Δt. The saturation point in the inductance is located by measuring the change in slew rate of the inductance during the measurement mode. Average values for the inductor and the slew rate can be determined using digital techniques. Other parameters such as current limit and on-time of the inductor can be adjusted by this methodology.