Cypress Semiconductor Corporation

Cathal O'Lionaird

Paul M Walsh

Markus Unseld

Oleksandr Hoshtanar

Thorsten Piper

Sean O'Sullivan

A device includes a signal bus to carry a sinusoidal drive signal and receive (RX) sensing hardware, coupled to an electrode of a touch panel, including an attenuator configured to detect a touch signal from the electrode, a multiplexer coupled between an input to the attenuator and the signal bus, and a capacitor coupled between the signal bus and the multiplexer. Control logic is coupled to the RX sensing hardware to perform a self-test, including to disconnect the RX sensing hardware from the electrode, cause the multiplexer to couple the capacitor to the input of the attenuator, determine whether an output of the RX sensing hardware is within a functional operating range.

Self-test for receive and transmit hardware functional safety associated with a touch panel or screen

A sense unit for inductive sensing or capacitive sensing is described. The sense unit may include a first terminal coupled to a first node, a first electrode coupled to the first node, and a second terminal. The sense unit may include a second electrode coupled to the second terminal. In a first mode, a first signal is received at the first terminal and a second signal is output on the second terminal, where the second signal may be representative of a capacitance of the sense unit. The sense unit may include an inductive coil. The sense unit may include a first capacitor. The inductive coil and the first capacitor are coupled in parallel between the first node and ground. In a second mode, a third signal is received at the first terminal and a fourth signal is output on the second terminal.

Combined inductive sensing and capacitive sensing

An apparatus for inductive sensing or capacitive sensing is described. The apparatus may include a signal generator to output on a first terminal a first signal in a first mode and a second signal in a second mode. The apparatus may include a charge measuring circuit to receive on a second terminal a third signal in the first mode and a fourth signal in the second mode. The third signal is representative of an inductance of a sense unit coupled between the first terminal and the second terminal. The fourth signal is representative of a capacitance of the sense unit.

Capacitance sensing and inductance sensing in different modes

An sense unit for inductive sensing or capacitive sensing is described. The sense unit may include a first terminal coupled to a first node, a first electrode coupled to the first node, and a second terminal. The sense unit may include a second electrode coupled to the second terminal. In a first mode, a first signal is received at the first terminal and a second signal is output on the second terminal, where the second signal may be representative of a capacitance of the sense unit. The sense unit may include an inductive coil. The sense unit may include a first capacitor. The inductive coil and the first capacitor are coupled in parallel between the first node and ground. In a second mode, a third signal is received at the first terminal and a fourth signal is output on the second terminal.

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Macroom, Ireland

Cathal O'Lionaird