Qualcomm Incorporated

Guangming Yin

Wenjun Su

Chiewcharn Narathong

Chulkyu Lee

Aristotele Hadjichristos

Le Od Zhang

Quanqing Zhu

Le Zhang

A feed-forward bias circuit biases body bias terminals of transistors of another circuit to compensate for PVT variations in the other circuit. In some aspects, the feed-forward bias circuit compensates for transistor process corners in a circuit by enabling the generation of different bias signals under different corner conditions. In some implementations, the feed-forward bias circuit is used to bias a delay circuit so that the delay circuit exhibits relatively constant delay characteristics over different PVT conditions.

Feed-forward bias circuit

An integrated circuit device () includes a first and second differential I/O pins (TRXP/TRXN) and a surge protection circuit. The surge protection circuit includes a protection transistor, a positive surge detection circuit, and a negative surge detection circuit. The protection transistor is connected between the first and second I/O pins and has a gate to receive a control signal (CTRL). The protection transistor is turned on to connect the I/O pins together if the positive surge detection circuit detects a positive surge energy on either of the I/O pins and/or if the negative surge detection circuit detects a negative surge energy on either of the I/O pins. The surge protection circuit provides increased protection for Ethernet device against undesirable energy in a manner that does not adversely affect the performance of the device.

Surge protection for differential input/output interfaces

Techniques for generating bias voltages for a multi-cascode amplifier. In an aspect, a multi-cascode bias network is provided, each transistor in the bias network being a replica of a corresponding transistor in the multi-cascode amplifier, enabling accurate biasing of the transistors in the multi-cascode amplifier. In another aspect, a voltage supply for the multi-cascode amplifier is provided separately from a voltage supply for the replica bias network, to advantageously decouple variations in the amplifier voltage supply from the bias network voltage supply. In yet another aspect, the bias voltages of transistors in the multi-cascode amplifier may be configured by adjusting the impedance of resistive voltage dividers coupled to the transistor gate biases. As the gain of the amplifier depends on the bias voltages of the cascode amplifiers, the gain of the amplifier may be adjusted in this manner without introducing a variable gain element directly in the amplifier signal path.

Multi-cascode amplifier bias techniques

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Newport Coast, CA, United States of America

Guangming Yin