发明授权
- 专利标题: Digital/analog converter
- 专利标题(中): 数字/模拟转换器
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申请号: US689441申请日: 1991-04-22
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公开(公告)号: US5323159A公开(公告)日: 1994-06-21
- 发明人: Akira Imamura , Hajime Obinata
- 申请人: Akira Imamura , Hajime Obinata
- 申请人地址: JPX Kodaira
- 专利权人: Nakamichi Corporation
- 当前专利权人: Nakamichi Corporation
- 当前专利权人地址: JPX Kodaira
- 优先权: JPX2-104586 19900420; JPX2-231218 19900831; JPX2-231219 19900831
- 主分类号: H03M1/68
- IPC分类号: H03M1/68
摘要:
A D/A converter divides an input digital data into at least two overlapping digital ranges. The data in the two ranges are converted separately from digital to analog by a low-range and a high-range DAC. The resulting analog signals are then added with a weighting that maintains the proper loudness relationships in the final combined analog output. In a low range of amplitudes, only the low-range DAC performs D/A conversion. Above a predetermined amplitude threshold, some of the high significant bits to the low-range DAC are frozen, while a remaining low significant bits of the low-range DAC are permitted to vary with the input digital data. Above the predetermined amplitude threshold, a digital value is subtracted from the data fed to the high-range DAC. The subtracted value is equal to the frozen value in the low-range DAC. In some embodiments, one or more supplementary bits are developed to smooth the transition between ranges. In other embodiments, more than two DACs receive overlapping ranges of the input digital data. In some of the embodiments, positive and corresponding negative analog representations of the ranges are connected in push-pull.
公开/授权文献
- US4565418A Insulation displacement terminal for nonmetallic core cable 公开/授权日:1986-01-21
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