Direct digital synthesis systems and methods
US10558236B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 26, 2018 |
| Grant date | Feb 11, 2020 |
| Priority date | — |
| Expiry date | Jun 26, 2038 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M1/742
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A direct digital synthesizer (DDS) is controlled by a suitably configured programmable logic device (PLD). The DDS includes a digital analog converter (DAC), and a coupled driver/buffer configured to drive relatively high capacitive loads with substantially rail to rail sinusoidal driver output signals and with little to no waveform distortion. The DAC includes a PMOS and NMOS DACs, and a switch configured to select the PMOS DAC for negative portions and the NMOS DAC for positive portions of an output analog signal generated by the DAC. The driver includes a pair of input differential amplifiers, PMOS and NMOS structures, which may be variable, and a pair of variable current sources. The PLD controls variable elements of the DDS to adjust the achievable positive and negative slew rates of the DDS, independently of one another, to reduce or eliminate risk of signal distortion while maintaining substantially stable rail to rail output.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.