发明名称 |
Variable-path-length voltage-controlled oscillator circuit |
摘要 |
A variable-path-length voltage-controlled oscillator circuit is provided. The oscillator circuit has a ring oscillator formed from a series of voltage-controlled inverter stages. The path length (i.e., the number of inverter stages) in the ring is selected based on path length configuration data stored in memory. The selected path length determines the nominal or center frequency of operation of the ring oscillator. The output frequency of the oscillator circuit is voltage-tuned about this center frequency by varying the delay of each inverter stage in the ring oscillator path. Various types of voltage-controlled inverter stages may be used, including current-starved inverter stages, variable-capacitive-load inverter stages, and differential-delay inverter stages. The voltage-controlled oscillator circuit may be used in a phase-locked loop on a programmable logic device for frequency synthesis or to eliminate clock skew.
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申请公布号 |
US5847617(A) |
申请公布日期 |
1998.12.08 |
申请号 |
US19970909337 |
申请日期 |
1997.08.11 |
申请人 |
ALTERA CORPORATION |
发明人 |
REDDY, SRINIVAS T.;JEFFERSON, DAVID EDWARD;CLIFF, RICHARD G.;MCCLINTOCK, CAMERON |
分类号 |
H03K3/03;H03L7/099;(IPC1-7):H03B5/24 |
主分类号 |
H03K3/03 |
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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