Digital-to-analog converter
US4727355A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 15, 1986 |
| Grant date | Feb 23, 1988 |
| Priority date | — |
| Expiry date | Apr 15, 2006 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M1/68
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A digital-to-analog converter (DAC) converts digital input data into an analog output signal with less harmonic distortion over an entire signal-level range. An exponent value detector detects from the digital input data the number of bits by which the digital input data is to be shifted to form a mantissa part thereof. A digital shifter shifts the digital input data in accordance with the output of the exponent value detector, and outputs the mantissa part which is then supplied to a mantissa-part DAC. The mantissa-part DAC comprises an R-2R resistor ladder network and outputs the result of DA conversion of the mantissa part to an exponent-part DAC. The exponent DAC shifts the output of the mantissa-part DAC by an amount determined by the output of the exponent value detector, and outputs the shifted signal as the analog output signal of this DAC. A control circuit is provided between the digital shifter and the mantissa-part DAC, which prevents, in accordance with the output of the exponent value detector, the least significant bits of the mantissa-part DAC from operatively functioning to thereby decrease the number of operable bits thereof when the magnitude of the digital input…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.