Split cell bowtie digital to analog converter and method
US6879276B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 18, 2003 |
| Grant date | Apr 12, 2005 |
| Priority date | — |
| Expiry date | Dec 18, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M1/745
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A DAC (10) including an operational amplifier (12) having an input terminal; a plurality of current paths coupled to the input terminal; a plurality of current sources (I1/2 -I4/2); and an arrangement (11) for switchably coupling current from at least two of the cells to a respective one of the paths in response to an input signal. In a specific embodiment, the inventive DAC (10) further includes a first resistive element (2R1-2R4) disposed in each of the current paths, a second resistive element (R1-R4) disposed between the current paths, and a feedback resistor (RF) disposed between an output terminal of the amplifier and the input terminal thereof. In the illustrative embodiment, the coupling arrangement includes a plurality of switches (SW1-SW4); each of the switches is adapted to switch half of the current from a first source and half of the current from a second source into a respective one of the paths. The invention is adapted to lower the distortion of digital to analog converters by improving differential nonlinearities and integral nonlinearities, caused primarily by current source gradient errors, without the need for trimming.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.