Methods and circuits for measuring mutual and self capacitance
First Claim
1. A capacitance measurement circuit, comprising:
- a first electrode capacitively coupled with a second electrode;
a first plurality of switches coupled with the first electrode; and
a second plurality of switches coupled with the second electrode, wherein, during a first operation stage, the first plurality of switches is configured to apply a first initial voltage to the first electrode and the second plurality of switches is configured to apply a second initial voltage to the second electrode, and wherein, during a second operation stage, the first plurality of switches is configured to connect the first electrode with a measurement circuit, and the second plurality of switches is configured to connect the second electrode with a constant voltage.
6 Assignments
0 Petitions
Accused Products
Abstract
A capacitance measurement circuit for measuring self and mutual capacitances may include a first electrode capacitively coupled with a second electrode, a first plurality of switches coupled with the first electrode, and a second plurality of switches coupled with the second electrode, wherein, during a first operation stage, the first plurality of switches is configured to apply a first initial voltage to the first electrode and the second plurality of switches is configured to apply a second initial voltage to the second electrode, and wherein, during a second operation stage, the first plurality of switches is configured to connect the first electrode with a measurement circuit, and the second plurality of switches is configured to connect the second electrode with a constant voltage.
-
Citations
19 Claims
-
1. A capacitance measurement circuit, comprising:
-
a first electrode capacitively coupled with a second electrode; a first plurality of switches coupled with the first electrode; and a second plurality of switches coupled with the second electrode, wherein, during a first operation stage, the first plurality of switches is configured to apply a first initial voltage to the first electrode and the second plurality of switches is configured to apply a second initial voltage to the second electrode, and wherein, during a second operation stage, the first plurality of switches is configured to connect the first electrode with a measurement circuit, and the second plurality of switches is configured to connect the second electrode with a constant voltage. - View Dependent Claims (2, 3, 4, 5)
-
-
6. A capacitance measurement method, comprising:
-
applying a first initial voltage to a first electrode during a first operation stage, wherein the first electrode is capacitively coupled with a second electrode; applying a second initial voltage to the second electrode during the first operation stage; connecting the first electrode with a measurement circuit during a second operation stage; and connecting the second electrode to a constant voltage during the second operation stage. - View Dependent Claims (7, 8, 9, 10)
-
-
11. A capacitance measurement circuit, comprising:
-
a first electrode capacitively coupled with a second electrode; a first plurality of switches coupled with the first electrode; a second plurality of switches coupled with the second electrode, wherein the first plurality of switches is configured to generate a current by connecting the first electrode to a first node during a first operation stage and a second node during a second operation stage, and wherein the second plurality of switches is configured to minimize a voltage difference between the second electrode and the first electrode during the first operation stage and during the second operation stage; and a measurement circuit configured to generate an output signal based on the current generated by the first plurality of switches. - View Dependent Claims (12, 13, 14)
-
-
15. A capacitance measurement method, comprising:
-
generating a net current by connecting a first electrode to a first node during a first operation stage, wherein the first electrode is capacitively coupled to a second electrode; connecting the first electrode to a second node during a second operation stage; and minimizing a voltage difference between the second electrode and the first electrode during the first operation stage and the second operation stage; and generating an output signal based on the net current. - View Dependent Claims (16, 17, 18, 19)
-
Specification