发明授权
US5428639A Two's complement pulse width modulator and method for pulse width
modulating a two's complement number
失效
二进制补码脉宽调制器和脉冲宽度调制二进制补码的方法
- 专利标题: Two's complement pulse width modulator and method for pulse width modulating a two's complement number
- 专利标题(中): 二进制补码脉宽调制器和脉冲宽度调制二进制补码的方法
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申请号: US202060申请日: 1994-02-25
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公开(公告)号: US5428639A公开(公告)日: 1995-06-27
- 发明人: Yair Orbach , Heinrich Iosub , Effi Orian
- 申请人: Yair Orbach , Heinrich Iosub , Effi Orian
- 申请人地址: IL Schaumburg
- 专利权人: Motorola, Inc.
- 当前专利权人: Motorola, Inc.
- 当前专利权人地址: IL Schaumburg
- 主分类号: H03M5/08
- IPC分类号: H03M5/08 ; H03K7/08
摘要:
A pulse width modulator (PWM) (20) receives a two's complement input number and separates a sign bit from remaining less significant bits. The PWM converts these bits into an unsigned number in dependence on the sign bit. A comparator (41) provides a compare output signal in response to an output of a counter (30) equaling the unsigned number. An output circuit (25) provides first and second pulse width modulated signals for a length of time determined by the output of the comparator (41) in dependence on whether the sign bit indicates a positive or negative sign. In one embodiment, the PWM (20) converts a negative two's complement number to the unsigned number by one's complementing the least significant bits, and the output circuit (25) keeps the second pulse width modulated signal active for one additional clock cycle to fully convert to two's complement form, without the need for a carry operation.
公开/授权文献
- US4422840A Venting device for a closed mold 公开/授权日:1983-12-27