David Siek Tam

6522178, Feb 18, 2003

Apr 24, 2001

09/840050

Ajit Dubhashi - Redondo Beach CA
David C. Tam - Manhattan Beach CA

International Rectifier Corporation - El Segundo CA

H03K 300

327108, 326 83

Circuits for communicating between high side devices and low side controllers without using level shifting switches are provided. A low voltage controller with time coding circuitry generates an output, such as a voltage, a current, or a digital signal for controlling a high side switch. A driver is connected to the high side switch and receives the signal from the controller, decodes the signal, and generates on and off time pulses for controlling the high side switch. The communication between the controller and the driver does not require any level shifting circuitry.

6891739, May 10, 2005

Mar 4, 2002

10/090281

Bruno C. Nadd - Lourmarin, FR
David C. Tam - Manhattan Beach CA, US
Mark Pavier - Guildford, GB
Glyn Connah - Glossop, GB

International Rectifier Corporation - El Segundo CA

H02M001/00

363147

A fully protected H-bridge for a d-c motor consists of two high side MOSFETs and a control and logic IC on a first conductive heat sink all within a first package and two discrete low side MOSFETs. The entire bridge is controlled by the IC. Shoot thru protection is provided for each leg, and a PMW soft start sequence is provided through the control of the low side MOSFETs, programed by an external, chargeable RC circuit. Input signals to the high side MOSFETs select the operation modes. Protective circuits are provided for short circuit current and over current conditions. Sleep mode and braking/non braking control is also provided.

7061195, Jun 13, 2006

Jul 24, 2003

10/625958

Eddy Ying Yin Ho - Torrance CA, US
Yong Li - Torrence CA, US
Jun Honda - El Segundo CA, US
David C. Tam - Manhattan Beach CA, US
Toshio Takahashi - Rancho Palos Verdes CA, US

International Rectifier Corporation - El Segundo CA

G05B 5/01
G05F 1/70

318438, 318448, 318456, 363 45

A motor drive system control provides global closed loop feedback to cooperatively operate system components to adaptively reduce noise and provide noise cancellation feedback. An active EMI filter reduces differential and common mode noise on an input and provides a noise level indication to a system controller. Power switches in both a power converter and power inverter are cooperatively controlled with dynamic dv/dt control to reduce switching noise according to a profile specified by the controller. The dv/dt control is provided as an analog signal to a high voltage IC and codified as a pulse width for a level shifting circuit supplying control signals to the high voltage gate drive. A noise extraction circuit and technique obtain fast noise sampling to permit noise cancellation and adaptive noise reduction.

7274241, Sep 25, 2007

Apr 5, 2006

11/398449

Eddy Ying Yin Ho - Torrance CA, US
Yong Li - Torrance CA, US
Jun Honda - El Segundo CA, US
David C Tam - Manhattan Beach CA, US
Toshio Takahashi - Rancho Palos Verdes CA, US

International Rectifier Corporation - El Segundo CA

H03K 17/16

327381, 327387, 327434, 327170

A gate driver for a power switch, comprising a gate drive circuit coupled to the gate of the power switch for at least one of turning on and turning off the power switch; a gate voltage control circuit in the gate drive circuit for controlling a voltage applied to the gate of the power switch during at least one of turning on and turning off the power switch; and a signal supplied to the gate voltage control circuit indicative of a voltage rate of change per unit time to be applied in at least one of turning on and turning off the power switch.

7405528, Jul 29, 2008

Jan 23, 2006

11/337282

Eddy Ying Yin Ho - Torrance CA, US
Yong Li - Torrance CA, US
Jun Honda - El Segundo CA, US
David Tam - Manhattan Beach CA, US
Toshio Takahashi - Rancho Palos Verdes CA, US

International Rectifier Corporation - El Segundo CA

G05B 5/01

31840025, 318448, 318456, 327381

A motor drive system control provides global closed loop feedback to cooperatively operate system components to adaptively reduce noise and provide noise cancellation feedback. An active EMI filter reduces differential and common mode noise on an input and provides a noise level indication to a system controller. Power switches in both a power converter and power inverter are cooperatively controlled with dynamic dv/dt control to reduce switching noise according to a profile specified by the controller. The dv/dt control is provided as an analog signal to a high voltage IC and codified as a pulse width for a level shifting circuit supplying control signals to the high voltage gate drive. A noise extraction circuit and technique obtain fast noise sampling to permit noise cancellation and adaptive noise reduction.

62117068, Apr 3, 2001

Jun 10, 1997

8/872450

Chongwook Chris Choi - Redondo Beach CA
David C. Tam - Redondo Beach CA

International Rectifier Corp. - El Segundo CA

H03K 300

327108

A method and circuit for driving power transistors arranged in series in a half bridge configuration allowing for excessive negative swing of an output node between the transistors in the half bridge configuration. The series transistors are connected between a first voltage source and a common potential. A second voltage reference source is also provided. A terminal is connected to a common point coupled to anodes of intrinsic diodes of driver circuits for the power transistors. The second voltage source is connected between the common potential and the terminal so as to shift the level of the common point such that the intrinsic diodes will not forward bias due to negative output node transients generated by diode forward recovery and stray inductances. The circuit of the invention can also be incorporated in an integrated circuit including a single chip, e. g. , a silicon chip.

55024122, Mar 26, 1996

May 4, 1995

8/433841

Chongwook C. Choi - Redondo Beach CA
David C. Tam - Redondo Beach CA

International Rectifier Corporation - El Segundo CA

H03K 190175

327333

A circuit for driving power transistors in a half bridge configuration from a control signal referenced to any potential between the line voltage for the power transistors and the line voltage return. The circuit includes an input circuit receiving a control signal referenced to any potential between the line voltage and the line voltage return, the input circuit being supplied with two voltage levels floating with respect to a common voltage level, a first level shifting circuit receiving an output of the input circuit which shifts the level of the output of the input circuit so that it is referenced to the common voltage level, a low side driver circuit for the power transistor in the half bridge configuration which functions as the low side power transistor, the low side driver circuit receiving the output referenced to the common voltage level, a second level shifting circuit which shifts the level of the output from the first level shifting circuit to produce a signal referenced to a second higher voltage level than said common level, and a driver circuit receiving the signal referenced to the second higher voltage level for driving the power transistor comprising the high side power transistor in the half bridge configuration. The circuit can be incorporated in an integrated circuit comprising a single chip, i. e. , a silicon chip.

53252586, Jun 28, 1994

Aug 26, 1992

7/936028

Chris Choi - Redondo Beach CA
David Tam - Redondo Beach CA

International Rectifier Corporation - El Segundo CA

H02H 326
G05F 1573

361 87

A circuit and method for driving a power transistor device. The circuit for driving a power transistor device has a driver having an input and an output, the output coupled to a control input of the power transistor device and the input coupled to a primary control voltage source for driving the power transistor device. A current sensing device is coupled to the power transistor device for providing a signal proportional to the current in the power transistor device. An amplifier is coupled to the current sensing device for providing a substantially linear control signal proportional to the current in the power transistor device, the linear control signal being provided to the input of the driver as a secondary drive signal for driving the power transistor device when a current level in the power transistor device greater than a threshold level is detected. A detector is provided for detecting when the current in the power transistor device is greater than the threshold level. The detector is coupled to the current sensing device and to a reference level source, and provides an overcurrent signal to the driver for switching the driver from being driven by the primary control voltage source to the secondary drive signal.