Smsc Holdings Sarl

Microchip Technology Inc.

James Ho

Hongming An

Wei Fu

CongQing Xiong

John Junling Zang

Henry Liang

Congqing Xiong

Circuitry of a physical layer for interfacing with a communication bus of a wired local area network is disclosed. The circuitry includes a variable delay driver operably coupled to a communication bus. The communication bus includes a shared transmission medium. The variable delay driver is configured to control a slew rate of a driven transmit signal at the driver output. The circuitry also includes receiver circuitry operably coupled to the communication bus. The circuitry further includes a common mode dimmer operably coupled to the receiver circuitry and the communication bus. The common mode dimmer is configured to protect the receiver circuitry from common mode interference.

Transceiver and driver architecture with low emission and high interference tolerance

Various techniques are provided to detect a state of a communication signal. In one example, a method of detecting a state of a signal includes receiving a differential communication signal comprising a positive portion and a complementary negative portion. The method also includes generating a common mode voltage signal from the positive portion and the negative portion of the communication signal. The method also includes rectifying the positive portion and the negative portion of the communication signal to provide a rectified signal. The method also includes comparing the common mode voltage, signal with the rectified signal. The method also includes generating a high frequency detect signal in response to the comparing. The method also includes determining whether the communication signal is in an idle state or a high frequency state based on the high frequency detect signal.

High frequency and idle communication signal state detection

Various techniques are provided to detect a state of a communication signal. In one example, a method of detecting a state of a signal includes receiving a differential communication signal comprising a positive portion and a complementary negative portion. The method also includes filtering the positive portion of the communication signal through a first low pass filter to provide a filtered positive portion of the communication signal. The method also includes filtering the negative portion of the communication signal through a second low pass filter to provide a filtered negative portion of the communication signal. The method also includes comparing the filtered positive portion of the communication signal with an internal reference voltage. The method also includes comparing the filtered negative portion of the communication signal with the internal reference voltage. The method also includes generating a low frequency detect signal in response to the comparing operations to indicate whether the communication signal is in a low frequency state.

Low frequency communication signal state detection

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San Diego, CA, United States of America

James Ho