US 2014/0210751 A1 · SEMICONDUCTOR DEVICE

Abstract

A semiconductor device including a display driving circuit that drives a display panel, a touch detection signal driving circuit that applies a touch detection signal to a touch sensor, and a touch state detection circuit that receives a signal obtained by observing the touch sensor is configured as follows. A connection switching circuit that switches connection between a terminal and an internal circuit is included therein. The connection switching circuit switches connection with the terminal by selecting one of at least two of the display driving circuit, the touch detection signal driving circuit and the touch state detection circuit. A protection circuit which is capable of changing a protection voltage level is connected to the terminal, and the protection voltage level varies depending on the signal amplitude of the circuit selected by the connection switching circuit.

Claims15

Dependent claims

A semiconductor device which is capable of being connected to a display panel including a touch sensor comprising:

a terminal;
a display driving circuit that drives the display panel;
a touch detection signal driving circuit that applies a touch detection signal to the touch sensor;
a touch state detection circuit that receives a signal obtained by observing the touch sensor;
a connection switching circuit;
a protection circuit, connected to the terminal, which is capable of changing a protection voltage level;
and
a protection voltage setting circuit which is capable of performing control for changing the protection voltage level,
wherein the connection switching circuit is capable of switching connection with the terminal by selecting one of at least two of the display driving circuit, the touch detection signal driving circuit and the touch state detection circuit, and
the protection voltage setting circuit is capable of setting the protection voltage level of the protection circuit in accordance with a signal amplitude of the circuit selected by the connection switching circuit.

7 more elements

A semiconductor device which is capable of being connected to a liquid crystal display panel, including a touch sensor to which a touch detection signal is input and which outputs a touch sensing signal, and including a display panel source terminal group to which a voltage to be applied to a liquid crystal is input and a display panel gate terminal group to which a signal for specifying a position of the liquid crystal to be supplied with the voltage is input, the semiconductor device comprising:

a host interface terminal group;
a source output terminal group that outputs a signal for driving the display panel source terminal group;
a first terminal group;
a display panel driving circuit that drives the display panel source terminal group and the display panel gate terminal group on the basis of display data which is input from the host interface terminal group;
a touch detection signal driving circuit that transmits the touch detection signal;
a first connection switching circuit;
a first protection circuit, connected to the first terminal group, which is capable of changing a first protection voltage level;
and
a protection voltage setting circuit which is capable of performing control for changing the first protection voltage level,
wherein the first connection switching circuit includes a level shift circuit which is capable of setting a converted voltage level, and is capable of being connected to the first terminal group by converting a signal amplitude level by the level shift circuit in which the converted voltage level is set, in accordance with a signal amplitude to be output by any one selected out of a circuit that outputs a signal for driving the display panel gate terminal group of the display panel driving circuit and the touch detection signal driving circuit, and
the protection voltage setting circuit is capable of setting the first protection voltage level in accordance with the signal amplitude of the circuit selected by the first connection switching circuit.

8 more elements

Dependencies are inferred from the claim text.

Semiconductor device

Life of this patent

Semiconductor device

Life of this patent

Abstract

Claims15