Low-noise transmitter system and method
US7274915B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 27, 2004 |
| Grant date | Sep 25, 2007 |
| Priority date | — |
| Expiry date | Sep 28, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2200/372
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A low-noise transmitter architecture and method for high linearity, high output-swing systems such as Asymmetrical Digital Subscriber Line (ADSL) systems. The transmitter uses a switched-current DAC having a current source coupled to ground, followed by a resistive transimpedance amplifier (TIA). The resistance of the current source is typically large enough so that noise from an op-amp included in the TIA is not significantly amplified at the output. The current source may be passive and may include at least one resistor connected to ground. With a passive current source, portions of a signal output by the DAC enter either the current source or the resistive transimpedance amplifier, but not both, eliminating noise in the system produced by the current source.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.