Hybrid pulse width-pulse rate digital-to-analog converter method and apparatus
US4095218A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 30, 1976 |
| Grant date | Jun 13, 1978 |
| Priority date | — |
| Expiry date | Aug 30, 1996 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M1/86
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A digital-to-analog converter method and apparatus is disclosed which utilizes a hybrid technique of combined pulse width and pulse rate modulation to achieve improved performance with reduced logic and circuitry requirements. Lower order bits of an N-bit digital data input for conversion to a corresponding analog output voltage level are treated in a manner similar to pulse rate modulation approaches utilized previously. High order bits are handled together in a variant form of pulse width (duration) modulation in which the pulse width required to generate the given analog voltage level corresponding to the high order digital bit inputs is divided into a fixed number of slices in a given sample time, each slice having a width or duration of pulse output which is variable in itself in correspondence to a function of both the high and low order bit value inputs. A low pass filter or integrator combines all of the pulses in a given sample to produce the analog voltage level output.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.