High output resistance, wide swing charge pump
US7583116B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 3, 2007 |
| Grant date | Sep 1, 2009 |
| Priority date | — |
| Expiry date | Sep 28, 2027 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L7/18
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
Disclosed are current sink and source circuits, a charge pump that incorporates them, and a phase locked loop that incorporates the charge pump. The current sink and source circuits each have a current mirror that biases a transistor connected to an output node. These circuits each further have a two-stage feedback amplifier to sense the current mirror drain voltage and to control the transistor gate voltage in order to stabilize the current mirror drain voltage independent of output voltage at the output node. The amplifier also increases output resistance at the output node. This configuration allows for a wide operation voltage range and ensures good circuit performance under a very low power supply. A charge pump that incorporates these circuits generates highly matched charging and discharging currents. A PLL that incorporates this charge pump exhibits minimal bandwidth shifts and minimal locking speed and jitter performance degradation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.