发明名称 |
Voltage controlled oscillator programmable delay cells |
摘要 |
A delay cell has selectable numbers of parallel load resistance transistors operable in parallel, and a similarly selectable number of bias current transistors connectable in parallel. The delay cell is preferably differential in construction and operation. A voltage controlled oscillator ("VCO") includes a plurality of such delay cells connected in a closed loop series. Phase locked loop ("PLL") circuitry includes such a VCO controlled by phase/frequency detector circuitry. The PLL can have a very wide range of operating frequencies as a result of the ability to control the number of load resistance transistors and bias current transistors that are active or inactive in each delay cell. Such activation/deactivation may be programmable or otherwise controlled. <IMAGE> |
申请公布号 |
EP1294093(A1) |
申请公布日期 |
2003.03.19 |
申请号 |
EP20020256302 |
申请日期 |
2002.09.11 |
申请人 |
ALTERA CORPORATION |
发明人 |
ANDRASIC, STJEPAN WILLIAM;PATEL, RAKESH H;LEE, CHONG H |
分类号 |
H03H11/26;H03K3/03;H03K3/354;H03K5/13;H03L7/099;H03L7/10 |
主分类号 |
H03H11/26 |
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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