Capacitive charge pump
First Claim
1. A charge pump, comprising:
- an output node;
a first capacitor having a first terminal coupled to a first circuit node; and
a first switch having a first current electrode coupled to the first circuit node, a control electrode coupled to receive a first switch control signal, and a second current electrode coupled to the output node, wherein the first switch control signal controls charge transfer between the first capacitor and the output node.
19 Assignments
0 Petitions
Accused Products
Abstract
A capacitive charge pump that can be implemented in such devices as e.g. a phase locked loop (PLL). The charge pump includes at least one capacitor in the charge path and discharge path for limiting the amount of charge provided to or removed from a filter capacitor of a PLL. In one example, a second capacitor may be provided in the charge path or discharge path to reduce the capacitance (if provided in series) or increase the capacitance (if provided in parallel) to adjust the maximum amount of charge transferred to a filter capacitor. In one example, multiple capacitive stages may be implemented in parallel to increase the maximum amount of charge transferred to a filter capacitor. Each stage is enabled after a delayed period of time from when the previous stage was enabled.
-
Citations
44 Claims
-
1. A charge pump, comprising:
-
an output node;
a first capacitor having a first terminal coupled to a first circuit node; and
a first switch having a first current electrode coupled to the first circuit node, a control electrode coupled to receive a first switch control signal, and a second current electrode coupled to the output node, wherein the first switch control signal controls charge transfer between the first capacitor and the output node. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 31)
-
-
28. A phase locked loop (PLL) circuit comprising:
-
a filter capacitor;
a phase frequency detector circuit having a first input to receive a first clock, a second input to receive a second clock, and a first output to provide a first clock control signal based on the first clock and the second clock;
a voltage controlled oscillator having an input coupled to a first terminal of the filter capacitor and an output to provide an output clock;
a charge pump having a first input to receive the first clock control signal and an output coupled to the first terminal of the filter capacitor and the input of the voltage controlled oscillator, the charge pump comprising;
a first capacitor having a first terminal; and
a first switch having a first current electrode coupled to the first terminal of the first capacitor, a control electrode coupled to receive the first clock control signal, and a second current electrode coupled to the first terminal of the filter capacitor, the first switch selectively coupling the first capacitor to the filter capacitor, based on the first clock control signal. - View Dependent Claims (29, 30, 32, 33, 34, 35)
-
-
36. A charge pump comprising:
-
an output node;
a charge path including a first capacitor;
a first switch including a control electrode coupled to receive a first charge control signal, wherein the first capacitor selectively provides charge, based on the first charge control signal, to the output node via the first switch;
a discharge path including a second capacitor;
a second switch having a control electrode coupled to receive a second charge control signal, wherein the second capacitor selectively receives charge, based on the second charge control signal, from the output node. - View Dependent Claims (37, 38, 39, 40, 41, 42, 43, 44)
-
Specification