Abstract: A first sampling capacitor 3 is connected between an output terminal of a first analog switch 1 and the ground, and an input terminal of a second analog switch 2 is connected to a node between the first analog switch 1 and the first sampling capacitor 3. A second sampling capacitor 4 is connected between an output terminal of the first analog switch 1 and the ground. A control part turning on the first and second analog switches 1 and 2 in a state in which an input voltage is applied to the input terminal of the first analog switch 1, thereafter turns off the second analog switch 2, subsequently turns off the first analog switch 1 and subsequently turns on the second analog switch 2.

Abstract: A voltage multiplying device of the present invention is provided with: a voltage multiplication level setting circuit for setting a voltage multiplying level which indicates how many times the power source voltage is multiplied; a voltage multiplication pulse signal generating circuit for outputting a plurality of voltage multiplication pulse signals, each having a predetermined period and varying with a predetermined phase difference; a condition decoder circuit and a voltage multiplication pulse selecting circuit for outputting a voltage multiplication controlling signal, which varies in accordance with the determined voltage multiplication level, in synchronization with the pulse signal; and a voltage multiplication level outputting circuit for multiplying the power source voltage step by step to the set voltage multiplication level in accordance with the voltage multiplication controlling signal and for outputting the voltage multiplication level in each of the steps.

Abstract: A liquid crystal display panel 51 of N rows.times.M columns is driven by a segment driver 52 with two different voltages VS1, VS2, and by a common driver 53 with three voltages VC1, VC2, VC3. An output voltage waveform of the segment driver 52 is modulated for gradation display. The two different voltages VS1, VS2 are selected to be low voltages so as not to require high withstand voltage process in the segment driver 52, which makes it easier to integrated to a large scale in the case of realizing the segment driver 52 as a semiconductor integrated circuit.

Abstract: A semiconductor device for driving a liquid crystal panel includes an output unit for generating output signals to drive a liquid crystal panel, a terminal for supplying a voltage from a power supply in the outside of the device, a voltage changing unit connected to the terminal for changing the voltage through the terminal into a voltage necessary for a self burn-in test and for supplying the output unit with the changed voltage, and a control unit for controlling the output unit to conduct the self burn-in test when a predetermined control signal is applied thereto from the outside of the device.