Analog Devices,inc.

Ara Arakelian

Piotr Olejarz

Stuart Patterson

Srivatsan Parthasarathy

Daniel Boyko

Sirui Luo

Georges El Bacha

Daniel Saari

Lewis Malaver

Electrostatic discharge protection for high speed transceiver interface is disclosed. In one aspect, an electrical overstress (EOS) protection device includes an anode terminal and a cathode terminal, a silicon controlled rectifier, a second NPN bipolar transistor including a base connected to the anode terminal and an emitter connected to an emitter of the first PNP bipolar transistor, and a second PNP bipolar transistor including an emitter connected to an emitter of the second NPN bipolar transistor and a base connected to a base of the first PNP bipolar transistor. Two or more paths for current conduction are present during a positive overstress transient that increases a voltage of the anode terminal relative to the cathode terminal, including a first path through the silicon controlled rectifier and a second path through the second NPN bipolar transistor and the second PNP bipolar transistor.

Electrostatic discharge protection for high speed transceiver interface

A method is described and in one embodiment includes detecting a transition of a data signal comprising a data packet received at a circuit while the circuit is in a first hysteresis mode; placing the circuit in a second hysteresis mode subsequent to the detecting; and returning the receiver to the first hysteresis mode subsequent to completion of receipt of the data packet to await receipt of a next data packet. In certain embodiments, the first hysteresis mode is a high hysteresis mode and the second hysteresis mode is a standard hysteresis mode. In some embodiments, a level of each of the first and second hysteresis modes is dynamically tunable.

Dynamic hysteresis circuit

A clock alignment detector described herein can detect alignment between clock signals within a defined margin of error, such as a defined margin of phase error. The margin of phase error can be varied to achieve various degrees of lock detection precision. Clock alignment detector can detect alignment between rising edges of the clock signals, falling edges of the clock signals, or both the rising and falling edges of the clock signals. The clock alignment detector can be implemented as a lock detector for a phase-locked loop that is configured to detect and maintain a phase relationship between a reference clock signal and a feedback clock signal, where the clock alignment detector detects alignment between the reference clock signal and the feedback clock signal.

Lock detector for phase-locked loop

A multi-voltage biasing system with over voltage protection has an amplifier with a stage including at least one output device and one cascode protection device having a predetermined maximum recommended voltage; a biasing network is selectively responsive to a plurality of different supply voltages at least one of which is higher than the maximum recommended voltage for providing to the stage a bias voltage to operate the cascode device and output device below their maximum recommended voltages.

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Watertown, MA, United States of America

Ara Arakelian