Altera Corporation

Vinh Van Ho

Tim Tri Hoang

Tien Duc Pham

Sergey Yuryevich Shumarayev

Thungoc M Tran

Simardeep Maangat

Mei Luo

Leon Zheng

Van Ton-That

Integrated circuits having transceivers capable of high-speed (e.g., 1 Gbps) operation without dedicated phase-locked loop circuitry are provided. One such integrated circuit device may include one or more transceivers capable of transmitting and receiving serial signals of approximately 1 Gbps or greater, and a multi-purpose phase-locked loop capable of providing a multi-phase clock signal to the one or more transceivers.

Multi-purpose phase-locked loop for low cost transceiver

A phase interpolator circuit includes first and second transistors coupled to form a differential pair, a load circuit, a first set of switch circuits, a second set of switch circuits, and a current source. The first set of switch circuits are coupled between the first transistor and the load circuit. The second set of switch circuits are coupled between the second transistor and the load circuit. The current source provides current for the differential pair.

Multi-phase interpolators and related methods

A level shifting circuit with a thin gate transistor connected to the input of the output stage is presented. The level shifting circuit has an input stage that receives an input that is at first voltage. A transistor with a thin gate oxide has one terminal connected to the input stage and another terminal coupled to an input of the output stage. The output stage of the level shifting circuit is implemented with thick gate oxide transistors.

Level shifter circuit with a thin gate oxide transistor

A phase interpolator circuit can include first and second transistors coupled to form a differential pair, first and second load circuits, a first switch circuit coupled between the first transistor and the first load circuit, a second switch circuit coupled between the second transistor and the second load circuit, a current source circuit, and a third switch circuit coupled between the differential pair and the current source circuit. A phase interpolator circuit can include three differential pairs of transistors. Six periodic input signals having six different phases are concurrently provided to control inputs of transistors in the three differential pairs of transistors. The phase interpolator circuit generates a selected phase in an output signal in response to four of the periodic input signals.

Techniques for phase interpolation

A dynamic flip-flop includes first and second input stages forming a differential input stage adapted to receive differential data. The flip-flop is reset in response to a reset signal. To ensure proper operation, a transistor disposed between the first and second input stages is always maintained active to provide a conduction path between the ground terminal and the nodes that may be charged from the supply voltage. To improve the setup and hold time of the flip-flop, the clock signal is applied to a first transistor disposed in the first input stage and a second transistor disposed in the second input stage.

Leakage compensation and improved setup/hold time in a dynamic flip-flop

In level-shifting circuitry for shifting low-voltage-domain signals to a high-voltage domain, one of two output transistors is driven with one of the low-voltage-domain signals, thereby reducing loading on the output and increasing output speed and bandwidth. The circuitry can be mirrored for differential operation. When included in a serial interface of a programmable logic device, the circuitry can be programmably selectable between single-ended and differential operation.

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San Jose, CA, United States of America

Vinh Van Ho