发明名称 |
LEAKAGE COMPENSATION FOR FILTER CAPACITORS IN PHASE-LOCKED LOOPS |
摘要 |
<p>A loop filter of a compensating phase-locked loop contains capacitors formed from transistors with thin gate oxide dielectric layers. Leakage current leaks through the capacitors. To avoid jitter in the output signal of the phase-locked loop that would otherwise be caused by the leakage current, a leakage compensation circuit is provided. The leakage compensation circuit of a first embodiment replicates the leakage current using a replication capacitor and a current mirror. The voltage across the replication capacitor is proportional to the control voltage of a voltage-controlled oscillator of the compensating phase-locked loop. A second embodiment generates the compensation current by controlling the voltage on the gate of a transistor. The gate voltage depends on charge added and subtracted by a charge pump in addition to the charge pumps in the loop filter. A third embodiment applies a leakage compensation circuit to a delay locked loop.</p> |
申请公布号 |
WO2005020438(A1) |
申请公布日期 |
2005.03.03 |
申请号 |
WO2004US25489 |
申请日期 |
2004.08.06 |
申请人 |
RAMBUS INC.;FRANS, YOHAN;NGUYEN, NHAT, M. |
发明人 |
FRANS, YOHAN;NGUYEN, NHAT, M. |
分类号 |
H03L7/081;H03L7/089;H03L7/093;(IPC1-7):H03L7/093 |
主分类号 |
H03L7/081 |
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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