High resolution circuit for converting capacitance-to-time deviation
First Claim
1. A high resolution circuit for converting a capacitance difference between a first and second capacitance into a phase difference between two pulse signals, the circuit comprising:
- a capacitance deviation detecting unit configured to generate first and second detection pulse signals having first and second frequencies corresponding to the first and second capacitances of a capacitive sensor, respectively;
a capacitance deviation amplifying unit configured to divide the frequencies of the first and second detection pulse signals to amplify a phase difference between the first and second detection pulse signals; and
a time signal generating unit configured to generate a time signal having a pulse width corresponding to the amplified phase difference,wherein the capacitance deviation detecting unit comprises first and second capacitance detecting units configured to generate the first and second detection pulse signals, respectively, andwherein the first capacitance detecting unit comprises;
a first comparator configured to output the first detection pulse signal having a first logical value when a first input node charged and discharged according to the first capacitance has a voltage level equal to or less than that of a first reference voltage, and otherwise to output the first detection pulse signal having a second logical value;
a first charging switch configured to apply a charging current to the first input node when the first detection pulse signal has the first logical value; and
a first discharging switch configured to discharge the first input node charged according to the first capacitance when the first detection pulse signal has the second logical value.
1 Assignment
0 Petitions
Accused Products
Abstract
There is provided a high resolution circuit for converting a capacitance-to-time deviation including a capacitance deviation detecting unit generating two detection signals having a phase difference corresponding to variations of capacitance of an micro electro mechanical system (MEMS) sensor; a capacitance deviation amplifying unit dividing frequencies of the two detection signals to amplify the phase difference corresponding to the capacitance deviation; and a time signal generating unit generating a time signal having a pulse width corresponding to the amplified phase difference.
29 Citations
19 Claims
-
1. A high resolution circuit for converting a capacitance difference between a first and second capacitance into a phase difference between two pulse signals, the circuit comprising:
-
a capacitance deviation detecting unit configured to generate first and second detection pulse signals having first and second frequencies corresponding to the first and second capacitances of a capacitive sensor, respectively; a capacitance deviation amplifying unit configured to divide the frequencies of the first and second detection pulse signals to amplify a phase difference between the first and second detection pulse signals; and a time signal generating unit configured to generate a time signal having a pulse width corresponding to the amplified phase difference, wherein the capacitance deviation detecting unit comprises first and second capacitance detecting units configured to generate the first and second detection pulse signals, respectively, and wherein the first capacitance detecting unit comprises; a first comparator configured to output the first detection pulse signal having a first logical value when a first input node charged and discharged according to the first capacitance has a voltage level equal to or less than that of a first reference voltage, and otherwise to output the first detection pulse signal having a second logical value; a first charging switch configured to apply a charging current to the first input node when the first detection pulse signal has the first logical value; and a first discharging switch configured to discharge the first input node charged according to the first capacitance when the first detection pulse signal has the second logical value. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
-
-
15. A high resolution circuit for converting a capacitance variation into a phase difference between two pulse signals, the circuit comprising:
-
a capacitance deviation detecting unit configured to generate first and second detection pulse signals having first and second frequencies corresponding to first and second capacitances of a capacitive sensor, respectively; a capacitance deviation amplifying unit configured to amplify a phase difference between the first and second detection pulse signals and including first and second signal frequency dividing units configured to divide the frequencies of the first and second detection pulse signals and generate first and second frequency-divided signals, respectively; and a time signal generating unit configured to generate a time signal having a pulse width corresponding to the amplified phase difference, wherein the first signal frequency dividing unit comprises a plurality of first D flip-flops serially connected in multiple stages, each of the first D flip-flops having an inverted output fed back as an input and receiving an output signal of a D flip-flop of a previous stage as a clock, and wherein the second signal frequency dividing unit comprises a plurality of second D flip-flops serially connected in multiple stages, each of the second D flip-flops having an inverted output fed back as an input and receiving an output signal of a D flip-flop of a previous stage as a clock. - View Dependent Claims (16, 17, 18, 19)
-
Specification