Cypress Semiconductor Corporation

Silego Technology Inc.

Kuang-Yu Chen

Chen Wang

I-Teh Sha

Jie Chen

Albert Chen

Ting-Yen Chiang

Joe Froniewski

Hyunbae Kim

Sen-Jung Wei

Frank Hwang

Trung Tran

Paul Lap Tak Cheng

Hueng-Cheng Eric Chen

A clock driving circuit and a method of driving a plurality of output lines for a PC architecture are disclosed. The clock driving circuit includes a clock generating circuit coupled to an output buffer for the PC having a plurality of output lines connected to a plurality of output loads having output load impedances. The output lines are driven differentially at an output voltage lower than a supply voltage. The circuit includes a voltage node having a voltage node impedance. The voltage node is maintained at substantially the output voltage. The circuit includes a current sinking transistor that sinks current from the voltage node. The current sinking transistor is operated in a linear region characterized by an ohmic resistance determined by the size of the current sinking transistor. The impedance of the voltage node is matched to one of the load impedances by sizing the current sinking transistor.

Reduced power output buffer

An apparatus comprising a circuit configured to generate a spread spectrum clock signal. The circuit may comprise a voltage controlled oscillator with a gain that may be automatically controlled.

Adaptive spread spectrum

An apparatus comprising a circuit that may be configured to (i) change a frequency of one or more first signals in response to a second signal and (ii) generate a third signal in response to either the second signal or a predetermined time period expiring.

Method and apparatus to generate clock and control signals for over-clocking recovery in a PLL

A line driver and a method for driving a line are disclosed. The line driver includes a first current device configured to initiate a change in the state of the line and a second current device configured to substantially complete the change. The first current device provides a first current and the second current device provides a second current that is smaller than the first current.

Line driving circuit

A circuit and method for controlling a spread spectrum transition are presented comprising a first circuit and a second circuit. The first circuit may be configured to generate a clock signal in response to (i) a reference signal, (ii) a sequence of spread spectrum ROM codes, and (iii) a command signal. The second circuit may be configured to synchronize the command signal to a feedback signal. The sequence of spread spectrum ROM codes may be generated according to a predetermined mathematical formula and optimized in accordance with predetermined criteria.

Circuit and method for controlling a spread spectrum transition

A spread spectrum clock generator comprising a spread spectrum modulation circuit and a control circuit. The spread spectrum modulation circuit may be configured to generate a clock signal in response to (i) a sequence of linearity ROM codes, (ii) a sequence of spread spectrum ROM codes, and (iii) a command signal. The control circuit may be configured to synchronize the command signal to a feedback signal. The sequence of linearity ROM codes and the sequence of spread spectrum ROM codes may be generated by predetermined mathematical formulas and optimized in accordance with predetermined criteria.

Circuit and method for linear control of a spread spectrum transition

A circuit comprising a current source, a first amplifier, and a second amplifier. The circuit may be used to provide for crossing point compensation of a CMOS driver as a function of a supply voltage. The current source may be configured to present a reference current. The first amplifier may be configured to (i) receive the reference current as a load, (ii) receive a first voltage, and (iii) present a second voltage responsive to the first voltage. The second amplifier may be configured to (i) receive the second voltage and (ii) change a current at a node responsive to the second voltage.

Output buffer crossing point compensation

An apparatus comprising a first circuit and a second circuit. The first circuit may be configured to generate an output signal having a frequency that varies in response to (i) a voltage signal and (ii) a load. The second circuit may be configured to generate the load by coupling one or more resistive devices to a reference node in response to a control signal.

Voltage control oscillator (VCO) with automatic gain control

A circuit and/or method comprising an oscillator circuit, a pulse detection circuit and a control circuit. The oscillator circuit may be configured to generate an output signal having a frequency in response to (i) a first control signal and (ii) a second control signal. The pulse detection circuit may be configured to generate a detect signal in response to the output signal. The control circuit may be configured to generate the second control signal in response to said detect signal.

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Saratoga, CA, United States of America

Kuang-Yu Chen