Derek D TamSanta Ana, CA

6828654, Dec 7, 2004

Dec 27, 2001

10/026470

Derek Tam - Irvine CA
Jasmine Cheng - Irvine CA
Jungwoo Song - Irvine CA
Takayuki Hayashi - Irvine CA

Broadcom Corporation - Irvine CA

H01L 2900

257532, 327157, 327558

In a low-pass filter for a phase locked loop (PLL) circuit, a capacitor formed by an N-type substrate, a P-type region formed on the N-type substrate, a thick oxide formed over the P-type region, a P gate electrode formed over the thick oxide and coupled to a first voltage supply line, and P pick-up terminals formed in the P-type region adjacent the gate electrode and coupled to a second voltage supply line, whereby a gate-to-substrate voltage is maintained at less than zero volts to maintain a stable control voltage for the PLL.

6882189, Apr 19, 2005

Oct 14, 2003

10/683262

Derek Tam - Irvine CA, US
Takayuki Hayashi - Irvine CA, US

Broadcom Corporation - Irvine CA

H03K021/00

327115, 327117, 327176, 377 47, 377 48

A programmable divider includes a synchronous counter configured to process an input clock signal and produce first output signals in response the input clock signal. A number of logic devices are coupled to the synchronous counter and configurable to receive the first output signals and correspondingly produce second output signals. Also included is a multiplexer that is configured to receive the second output signals and has an output coupled to an input of the synchronous counter. In the programmable divider, characteristics of the synchronous counter are selectable based upon a particular number of the logic devices configured.

7005898, Feb 28, 2006

Sep 22, 2004

10/946172

Derek Tam - Irvine CA, US
Takayuki Hayashi - Irvine CA, US

Broadcom Corporation - Irvine CA

H03K 21/00

327115, 327117, 327176, 377 47, 377 48

A programmable divider includes a synchronous counter configured to process an input clock signal and produce first output signals in response the input clock signal. A number of logic devices are coupled to the synchronous counter and configurable to receive the first output signals and correspondingly produce second output signals. Also included is a multiplexer that is configured to receive the second output signals and has an output coupled to an input of the synchronous counter. In the programmable divider, characteristics of the synchronous counter are selectable based upon a particular number of the logic devices configured.

7098738, Aug 29, 2006

Dec 24, 2003

10/744785

Derek Hing-Sang Tam - Irvine CA, US
Ardie Venes - Laguna Niguel CA, US

Broadcom Corporation - Irvine CA

H03G 3/30

330284

A programmable gain amplifier with three stages uses fine steps, has a large gain range, and is monotonic. The first stage comprises several amplifiers, each including a resistive feedback loop. The feedback loop comprises a series of resistors, with each resistor acting as a tap. Since the number of resistors in the loop is unchanging, monotonicity and stability is guaranteed when resistance is increased using successive taps. A switch system connects two taps at a time to an interpolation stage. Each of these taps corresponds to a specific resistor level, and thus a gain level. The interpolation stage uses a plurality of current sources inside a feedback amplifier to control the interpolation, in order to provide fine gain steps.

7547956, Jun 16, 2009

Oct 28, 2004

10/975090

Derek Tam - Irvine CA, US
Jasmine Cheng - Irvine CA, US
Jungwoo Song - Irvine CA, US
Takayuki Hayashi - Irvine CA, US

Broadcom Corporation - Irvine CA

H01L 23/58

257532, 257368, 438307, 438379, 327157, 327558

A circuit with dielectric thicknesses is presented that includes a low-pass filter including one or more semiconductor devices having a thick gate oxide layer, while further semiconductor devices of the circuit have thin gate oxide layers. The low-pass filter semiconductor device includes an N-type substrate, a P-type region formed on the N-type substrate, a thick gate oxide layer formed over the P-type region, a P gate electrode formed over the thick gate oxide layer and coupled to a first voltage supply line, and P pick-up terminals formed in the P-type region adjacent the gate electrode and coupled to a second voltage supply line. The low-pass filter semiconductor device acts as a capacitor, whereby a gate-to-substrate voltage is maintained at less than zero volts to maintain a stable control voltage for the circuit.

7982491, Jul 19, 2011

Apr 8, 2009

12/384793

Joseph Aziz - Irvine CA, US
Andrew Chen - Redondo Beach CA, US
Derek Tam - Irvine CA, US
Agnes Neves Woo - Encino CA, US
Marcel Lugthart - Aliso Viejo CA, US

Broadcom Corporation - Irvine CA

H03K 17/16
H03K 19/003

326 30, 326 34, 326 86

According to one exemplary embodiment, an active termination circuit includes at least one active termination branch, where the at least one active termination branch includes at least one transistor for providing an active termination output. The at least one active termination branch further includes an amplifier driving the at least one transistor, where the amplifier has a non-inverting input coupled to the active termination output via a feedback network. The amplifier controls a current flowing through the at least one transistor so as to provide the active termination output. The active termination output can be provided at a drain of the at least one transistor, where a source of the at least one transistor is coupled to ground through a degeneration transistor and a tail current sink.

8148219, Apr 3, 2012

Jun 15, 2009

12/484652

Derek Tam - Irvine CA, US
Jasmine Cheng - Irvine CA, US
Jungwoo Song - Irvine CA, US
Takayuki Hayashi - Irvine CA, US

Broadcom Corporation - Irvine CA

H01L 21/338

438177, 438307, 257288, 257E21623

A circuit with dielectric thicknesses is presented that includes a low-pass filter including one or more semiconductor devices having a thick gate oxide layer, while further semiconductor devices of the circuit have thin gate oxide layers. The low-pass filter semiconductor device includes an N-type substrate, a P-type region formed on the N-type substrate, a thick gate oxide layer formed over the P-type region, a Pgate electrode formed over the thick gate oxide layer and coupled to a first voltage supply line, and Ppick-up terminals formed in the P-type region adjacent the gate electrode and coupled to a second voltage supply line. The low-pass filter semiconductor device acts as a capacitor, whereby a gate-to-substrate voltage is maintained at less than zero volts to maintain a stable control voltage for the circuit.

8183885, May 22, 2012

Apr 8, 2009

12/384795

Joseph Aziz - Irvine CA, US
Andrew Chen - Redondo Beach CA, US
Derek Tam - Irvine CA, US

Broadcom Corporation - Irvine CA

H03K 19/094

326 86, 326 83, 327109, 341145

In one embodiment, a circuit for providing a tail current for a line driver includes an adjustable current source. The adjustable current source includes a number of current source cells coupled together in a parallel configuration, where the current source cells are configured to provide the tail current for the line driver in response to a digital control signal. The circuit can further include a digital core coupled to the adjustable current source, where the digital core provides the digital control signal. The digital control signal provides a number of bits, where each bit controls one of the current source cells. In one embodiment, a current source cell can comprise a number of current source sub-cells. The current source cells can be configured to provide the tail current for the line driver in response to the digital control signal when the line driver is operating in a class AB mode.