| 摘要 |
PROBLEM TO BE SOLVED: To improve nonlinear operating characteristics of a charge pump when operated at low current levels.SOLUTION: The charge pump comprises an UP current mirror circuit 182 and a DN current mirror circuit 181. The UP current mirror circuit is controlled by an input UP signal 151 and the DN current mirror circuit is controlled by an input DN signal 146 and supplies or draws charge onto or from an output node 193.To prevent disturbances on bias nodes 214 and 198 of the UP current mirror circuit and the DN current mirror circuit, replica circuits 184 and 183 are provided. The replica circuits 184 and 183 are coupled to the bias nodes 214 and 198 and controlled by input signals 145 and 150 of opposite polarities to the input signals 151 and 146 which control the current mirror, so that the replica circuits create disturbances that tend to counteract disturbances created by switching of the current mirror. |
