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US 2017/0083161 A1Published application
Low noise capacitive sensor with integrated bandpass filter
AssigneeTexas Instruments Incorporated
InventorsKaran Singh Jain, Harish Venkataraman
Life of this patent
Estimating the term…
Abstract
A bandpass sense amplifier circuit (FIG. 2A) is disclosed. The circuit includes a capacitor (C0) having a first terminal coupled to receive an input signal (Vin) and a second terminal. A current conveyor circuit (200-206,212) has a third terminal (X) coupled to the second terminal of the capacitor and a fourth terminal (Z) arranged to mirror a current into the third terminal. A voltage follower circuit (214) has an input terminal coupled to the fourth terminal of the current conveyor circuit and an output terminal.
Claims20
A circuit, comprising:
- a capacitor having a first terminal coupled to receive an input signal and having a second terminal;
- a current conveyor circuit having a third terminal coupled to the second terminal of the capacitor and having a fourth terminal arranged to mirror a current into the third terminal;
- and
- a first voltage follower circuit having an input terminal coupled to the fourth terminal of the current conveyor circuit and having an output terminal.
1 more element
A circuit, comprising:
- a capacitor having a first terminal coupled to receive an input signal and having a second terminal;
- a first current conveyor circuit having a third terminal coupled to the second terminal of the capacitor and having a fourth terminal arranged to mirror a current into the third terminal;
- and
- a second current conveyor circuit having an input terminal coupled to the fourth terminal of the first current conveyor circuit and having an output terminal arranged to mirror a current into the input terminal.
1 more element
A touch screen system, comprising:
- a voltage source arranged to produce a drive voltage having a frequency;
- a plurality of first electrodes arranged to selectively receive the drive voltage;
- a plurality of second electrodes proximate the plurality of first electrodes;
- a bandpass sense amplifier, comprising a first current conveyor circuit and a first voltage follower circuit, selectively coupled to the plurality of second electrodes;
- an analog to digital converter (ADC) coupled to receive an output signal from the bandpass sense amplifier;
- and
- a processor coupled to receive an output signal from the ADC.
4 more elements
Dependencies are inferred from the claim text.