Analog Devices,inc.

Roger B Huntley, Jr

Reuben Pascal Nelson

David T Crook

Charles D Lane

Ken Gentile

Thomas E Tice

Jon T Baird

Synthesizers are provided to generate synthesizer signals in response to primary digital signal representations that are created by a signal generator. In an important feature, the synthesizers further include a signal corrector that inserts correction digital signal representations to at least partially cancel a corresponding spurious component in the primary digital signal representation and thereby provide synthesizer signals with reduced spurious content.

Synthesizer structures and methods that reduce spurious signals

A new differential ladder/comparator circuit reduces settling time delays in parallel analog to digital converters. A parallel analog-to-digital converter (ADC) includes a pair of differential resistor ladders having their taps connected to a group of comparators. The comparators produce digital 'thermometer' scale outputs corresponding to analog signals impressed upon the differential ladders. By employing double-value resistors to form the 'rungs' of the ladders and by connecting the comparators to the ladder taps in a way that increases the number of comparator inputs connected to the ladders' lower-order taps and decreases the number of comparator inputs connected to the ladders' higher order taps, the input impedance presented by the ladder/comparator combination is reduced in comparison with conventional differential ladder parallel ADCs. Additionally, input signals are superimposed upon the ladders by drivers which, in a preferred embodiment, present lower output impedances to the ladders than prior art drivers, further improving the bandwidth of the ADC.

High bandwidth parallel analog-to-digital converter

Growing community of inventors

Colfax, NC, United States of America

Roger B Huntley, Jr