Steven D Harris

6794917, Sep 21, 2004

Jul 14, 2003

10/620100

Steven Michael Barrow - Gilbert AZ
Robert Kenneth Oppen - Chandler AZ
Steven Harris - Chandler AZ

National Semiconductor Corporation - Santa Clara CA

H03K 310

327227, 323282

The on-time of a pulse signal is controlled by comparing a ramp signal to an input signal that is dynamically selected from two signals. A first operating mode is active when a clock signal is in a first logic state, where the pulse signal is reset. A second operating mode is initiated when the clock signal changes from the first logic state to a second logic state. During the second operating mode, the ramp signal is compared to the first signal. A third operating mode is initiated when the ramp signal exceeds the first signal during the second operating mode. During the third operating mode, the pulse signal is set and the ramp signal is compared to the second signal. The pulse signal is reset when the when the ramp signal exceeds the second signal in the third operating mode such that the on-time of the pulse signal is controlled.

6828836, Dec 7, 2004

Sep 9, 2003

10/658505

Steven Michael Barrow - Gilbert AZ
Robert Kenneth Oppen - Chandler AZ
Steven Harris - Chandler AZ

National Semiconductor Corporation - Santa Clara CA

H03K 3017

327172, 327174

Two comparators are arranged to generate a pulse-width modulator (PWM) control pulse. The first comparator is arranged to start the PWM control pulse, while the second comparator is arranged to stop the PWM control pulse. The first comparator can be a high speed CMOS comparator that includes a built-in offset. The first and second comparators can be arranged such that the built-in offset of the first comparator dominates the overall operation at the start of the control pulse. The start of the PWM control pulse is initiated by a ramp voltage and a predetermined reference level instead of a clock edge. The PWM control pulse can be linearly varied down to a zero pulse width. The PWM control pulse may be used to control the on-time of the switching element in a switching-type converter.

8193798, Jun 5, 2012

Oct 29, 2009

12/608676

W. David Pace - Phoenix AZ, US
Robert H. Bell - Tempe AZ, US
Steven L. Harris - Chandler AZ, US

Texas Instruments Incorporated - Dallas TX

G05F 1/00

323284, 323288

A method includes generating a drive signal for a transistor in a switching regulator. The drive signal turns the transistor on and off to generate a regulated output voltage. The drive signal is generated based on a clock signal. The method also includes dynamically decreasing a frequency of the clock signal to decrease a dropout voltage of the switching regulator. Dynamically decreasing the frequency of the clock signal can increase a duration of switching periods defined by the clock signal. The dropout voltage could have a first value proportional to T/Tduring shorter switching periods and a second value proportional to T/Tduring longer switching periods. Trepresents a minimum amount of off-time for the transistor during each switching period, Trepresents a maximum amount of on-time for the transistor during shorter switching periods, and Trepresent a maximum amount of on-time for the transistor during longer switching periods.

43520561, Sep 28, 1982

Dec 24, 1980

6/220207

David L. Cave - Tempe AZ
Steven L. Harris - Mesa AZ
Don W. Zobel - Tempe AZ

Motorola, Inc. - DE

G05F 318

323314

A two transistor voltage reference circuit controls the ratio of the current densities of two transistors by a negative feedback loop. A voltage corresponding to the difference in the base-to-emitter voltages of the two transistors is developed which has a positive temperature coefficient (TC) and which is connected in series with the base-to-emitter voltage of one of the two transistors having a negative TC. The circuit parameters are selected so that the resultant combined voltage has a predetermined, composite TC. A zener diode is included in the negative feedback loop and arranged to have a TC which cancels the predetermined composite TC to develop a reference voltage having a high magnitude that has minimal variation with temperature change.