Charge pump with wide operating range

摘要

A charge pump at least includes a current source, a first switch, a second switch, a level-shift circuit, and a capacitor. The first switch is coupled between the current source and an internal node. The capacitor is coupled between the internal node and the level-shift circuit. The second switch is coupled between the internal node and an output node. The first switch performs a closing-and-opening operation and the level-shift circuit performs a level-shift operation while the second switch is kept open and the internal node is isolated from the output node. The operating range of the charge pump is effectively widened by using the proposed design.

主权项

1. A charge pump, comprising:
a first current source; a first switch, coupled between the first current source and a first node; a first level-shift circuit; a first capacitor, coupled between the first node and the first level-shift circuit; and a second switch, coupled between the first node and an output node, wherein the first switch performs a closing-and-opening operation and the first level-shift circuit performs a level-shift operation while the second switch is kept open; a second current source; a third switch, coupled between the second current source and a second node; a second level-shift circuit; a second capacitor, coupled between the second node and the second level-shift circuit; and a fourth switch, coupled between the second node and the output node; wherein the third switch performs a closing-and-opening operation and the second level-shift circuit performs a level-shift operation while the fourth switch is kept open, wherein the first current source supplies a current to the first node, and the second current source draws a current from the second node.