Charge pump with wide operating range
First Claim
Patent Images
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.
1 Assignment
0 Petitions
Accused Products
Abstract
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.
-
Citations
17 Claims
-
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. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
-
-
15. A method for operation of a charge pump, comprising the steps of:
-
providing the charge pump which comprises a first current source, a first level-shift circuit, a first switch, a second switch, a first capacitor coupled to a first node, a second current source, a second level-shift circuit, a third switch, a fourth switch, and a second capacitor coupled to a second node; supplying a current to the first node by the first current source; changing a logic level of the first capacitor by the first level-shift circuit; coupling the first current source to the first node by the first switch; isolating the first current source from the first node by the first switch; recovering the logic level of the first capacitor by the first level-shift circuit; coupling the first node to an output node of the charge pump by the second switch; isolating the first node from the output node of the charge pump by the second switch; drawing a current from the second node by the second current source; changing a logic level of the second capacitor by the second level-shift circuit; coupling the second current source to the second node by the third switch; isolating the second current source from the second node by the third switch; recovering the logic level of the second capacitor by the second level-shift circuit; coupling the second node to the output node of the charge pump by the fourth switch; and isolating the second node from the output node of the charge pump by the fourth switch. - View Dependent Claims (16, 17)
-
Specification