发明授权
- 专利标题: Method of analog/digital conversion
- 专利标题(中): 模拟/数字转换方法
-
申请号: US244552申请日: 1988-09-12
-
公开(公告)号: US4989005A公开(公告)日: 1991-01-29
- 发明人: Yoshihiro Wakiyama , Yoshiro Ohnishi
- 申请人: Yoshihiro Wakiyama , Yoshiro Ohnishi
- 申请人地址: JPX Kyoto
- 专利权人: Horiba, Ltd.
- 当前专利权人: Horiba, Ltd.
- 当前专利权人地址: JPX Kyoto
- 优先权: JPX60-203324[U] 19851228
- 主分类号: G01R19/04
- IPC分类号: G01R19/04 ; H03M1/00 ; H03M1/54
摘要:
An analog/digital converter includes a peak holding circuit for holding a peak voltage of input analog data and a peak time detecting circuit for detecting a point of time when the input analog data reaches a peak voltage. Also included is a constant current discharging circuit for discharging the peak voltage held in the peak holding circuit at a constant current from the peak point of time detected by the peak time detecting circuit. The converter also includes a zero time detecting circuit for detecting a zero point of time when a voltage held in the peak holding circuit is reduced to zero and a time to digital converting circuit for counting a number of pulses in a pulse line obtained by gating clock pulses during a period of time from the peak time detected by the peak detecting circuit to the zero time detected by the zero time detecting circuit, the time to digital converting including a counter to output digital data corresponding to the input analog data. A positive offset analog voltage is added to the input analog data and a digital compensator compensates the digital data obtained by the time to digital converting circuit by providing a negative offset digital value approximately corresponding to the positive offset analog voltage, more correctly, equal to a number of pulses in a pulse line passing through a clock gate of the time-to-digital converting circuit for a period of time during which the input analog data has a value equal to zero.