Semiconductor switch

Abstract

A challenge in outputting a voltage near the midpoint potential in a semiconductor switch which operates based on a low voltage power supply is to avoid a decrease in operation speed and a deterioration in accuracy of the output voltage which would be caused due to an increase in ON-resistance or occurrence of current leakage. Thus, a structure including a gray level generation circuit (100), an analog switch circuit (111) and a backgate voltage control circuit (122) is provided wherein the backgate voltage of each of an N-channel MOS transistor (112) and a P-channel MOS transistor (113) of the analog switch circuit (111) to which the voltage of the gray level generation circuit (100) is input is supplied from the backgate voltage control circuit (122) which has an equal structure as that of the gray level generation circuit(100).

Description

technical field [0001] The present invention relates to a semiconductor switch, and more particularly to a semiconductor switch with low on-state resistance, small size, low cost, and excellent switching responsiveness. Background technique [0002] A prior art semiconductor switch will be described with reference to FIG. 6 . The semiconductor switch shown in Fig. 6 is made up of the gray level generation circuit 400 that produces gray level voltage, analog switch circuit 410 and switch control circuit 420, the arbitrary gray level of gray level generation circuit 400 is controlled by analog switch circuit 410. The stage voltage VM is delivered to the output terminal. [0003] As shown in Figure 6, the analog switch circuit 410 is generally composed of a P-channel MOS transistor 412 and an N-channel MOS transistor 411 connected in parallel, and the sources and drains of the P-channel MOS transistor 412 and the N-channel MOS transistor 411 are connected to each other respect...

AI Technical Summary

Problems solved by technology

[0009] In order to avoid the above-mentioned problems, methods of changing the size of MOS transistors, lowering the threshold voltage, and adopting depletion-type MOS transistors can be used, but these methods cause increased leakage current and increased chip cost (see Patent Document 1)

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