Analog Devices,inc.

Piotr Olejarz

Ara Arakelian

Srivatsan Parthasarathy

Stuart Patterson

Daniel Boyko

Sirui Luo

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 voltage regulator is provided comprising: a pass transistor that includes a first node coupled to receive an input voltage and a second node coupled to provide a regulated voltage and a control node; an amplifier circuit coupled to produce a control voltage on a control line that is coupled to control a voltage at the control node of the pass transistor, based at least in part upon a reference voltage and the regulated voltage; a switch configured to transition between a first switch state in which the switch couples the control line to a turn-off voltage having a value to turn off the pass transistor and a second switch state in which the switch decouples the control line from the turn-off voltage; and a switch control circuit configured to maintain the switch in the first switch state during a first time interval while the input voltage ramps up and to transition the switch to the second switch state after the first time interval.

Soft start circuit and method for DC-DC voltage regulator

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.

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Watertown, MA, United States of America

Piotr Olejarz