发明名称 |
Enhanced operational frequency for a precise and programmable duty cycle generator |
摘要 |
A precise and programmable duty cycle adjuster which can produce a user definable duty cycle clock signal comprises a digital to analog converter (DAC), low pass filter (LPF), operational transconductance amplifier (OTA), and a unique voltage controlled duty cycle generator (VCDCG). The circuit has the ability to produce a user programmable duty cycle clock signal with precision over a broad range of operational frequencies. The VCDCG circuit employs a number of delay stages, each of which has a current starved inverter which is immediately followed by a conventional inverter to allow duty cycle corrections to be either additive or subtractive. For a fixed number of delay stages, the range of duty cycle selection is inversely proportional to the frequency of an input clock signal. This frequency range limitation is alleviated by designing the VCDCG with a multiple number of delay taps in conjunction with multiple tap points which are multiplexed at the output.
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申请公布号 |
US6509771(B1) |
申请公布日期 |
2003.01.21 |
申请号 |
US20010017071 |
申请日期 |
2001.12.14 |
申请人 |
INTERNATIONAL BUSINESS MACHINES CORPORATION |
发明人 |
ATALLAH FRANCOIS I.;CORREALE, JR. ANTHONY |
分类号 |
H03K3/017;H03K5/00;H03K5/13;H03K5/156;(IPC1-7):H03K3/017 |
主分类号 |
H03K3/017 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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