Lsi Logic Corporation

Silicon Bridge Inc.

Tae-Song Chung

Hong Hao

Keven Hui

See-Hoi Caesar Wong

The digitally programmable delay circuit to correct timing skew between data and clock is developed. The digitally programmable delay circuit may be built by cascading delay cells. The delay circuit uses delay cells comprising simple digital elements such as inverters and tri-state inverters to eliminate the intrinsic delay and achieves linearity and monotinicity. The delay cell may be used as a building module which is repeatedly used in a serial fashion. The delay range is fully programmable from the delay of one delay cell to infinity if the chip area is available. The delay range can be scaled by adding more delay cells.

High speed fully scaleable, programmable and linear digital delay circuit

An input buffer circuit includes a first differential circuit, a second differential circuit, a pull-up circuit, and a pull-down circuit. An input voltage and a reference voltage are provided to the first and second differential circuits. The first differential circuit detects rising edges of the input voltage and causes the pull-up circuit to quickly drive an output voltage to logic high. The second differential circuit detects falling edges of the input voltage and causes the pull-down circuit to quickly drive the output voltage to logic low.

Input buffer circuit having equal duty cycle

A method and apparatus for optimizing crossover voltage for differential pair switches in a current-steering digital-to-analog converter or the like are disclosed. An array of at least one or more MOSFET switches may be utilized to control the crossover voltage of a differential pair of transistors such that the off time overlap of the differential pair transistors is optimized. In one embodiment, the pull-up and pull-down times of the input for the differential pair transistors are optimized such that the differential pair transistors are not turned off simultaneously. The array of switches may be n-channel MOSFETs when the differential pair are p-channel MOSFETs. Likewise, the array of switches may be p-channel MOSFETs when the differential pair are n-channel MOSFETs. The output of the diflerential pair is free of crossover glitches and is capable of being utilized in a data converter such as a current-steering digital-to-analog converter (DAC).

Growing community of inventors

Danville, CA, United States of America

Tae-Song Chung