Floating output digital to analog converter
US4961045A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 27, 1989 |
| Grant date | Oct 2, 1990 |
| Priority date | — |
| Expiry date | Oct 27, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M1/664
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A digital to analog converter circuit produces an output voltage which includes a small error voltage floating on a larger direct current voltage component. The circuit includes a controlled current supply coupled to the emitter of an NPN transistor to which the direct current voltage component is supplied to the base thereof. The error voltage is generated by modulating the current through the transistor by controlling the current supply, independent of the voltage component supplied to its base, such that the output voltage occurring at the emitter of the transistor is a function of the difference between the direct current component and the natural log of the modulated emitter current.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.