Abstract: A drive circuit for a display panel has a D/A conversion circuit which has a unit region serving as a circuit element that is formed in an IC. Contact pads are provided at both ends in a rectangular guard ring region and at the center thereof. Further, a plurality of MOS switch transistors are arranged and formed respectively between these contact pads. The contact pads arranged at both ends in the unit region, respectively receive one of a plurality of analog voltages. The contact pad at the center is connected to a predetermined output, and the respective switch transistors in the unit region are respectively operated as switch circuits. An analog conversion voltage is obtained by selecting ON/OFF of the plurality of switch transistors in the unit region in response to data.

Abstract: A drive circuit for a display panel has a D/A conversion circuit which has a unit region serving as a circuit element that is formed in an IC. Contact pads are provided at both ends in a rectangular guard ring region and at the center thereof. Further, a plurality of MOS switch transistors are arranged and formed respectively between these contact pads. The contact pads arranged at both ends in the unit region, respectively receive one of a plurality of analog voltages. The contact pad at the center is connected to a predetermined output, and the respective switch transistors in the unit region are respectively operated as switch circuits. An analog conversion volta e is obtained by selecting ON/OFF of the plurality of switch transistors in the unit region in response to data.