Semiconductor device and electronic apparatus

Abstract

The invention can ensure an external power supply not to be cut off by using initialization of a drive unit, so the control can be finished without being cut off in the process; the solving method comprises the following steps: forming a first internal power supply voltage (VDD) from the first external power supply voltage (IOVCC); forming a second internal power supply voltage (AVDD) from the second external power supply voltage (VSP) with higher voltage absolute value than the first external power supply, setting detection circuits (22, 23) capable of checking abnormal conditions of the external power supply being cut in the power supply circuit, wherein the detection circuits can start the initialization sequence; when the detection circuits detect the first external power supply is abnormal, using the second external power supply as the work power supply and to compensate a dropping auxiliary amplifier (21) and a sample keeping circuit (SH1) of the reference voltage (VRdiv) of the auxiliary amplifier under the first internal power supply voltage, wherein the sample keeping circuit is in the keeping state according to the abnormal detection of the first external power supply voltage.

Description

technical field [0001] The present invention relates to a control technique for coping with unexpected power supply abnormalities in semiconductor devices and electronic equipment, for example, relates to an effective technique applicable to a liquid crystal display driver. Background technique [0002] When the external power supply to the driving semiconductor device such as the liquid crystal driver is cut off, it is necessary to initialize the state of the driven device such as the liquid crystal display panel before the semiconductor device becomes inoperable. This is to prevent undesired charge information from remaining in the pixels of the liquid crystal display panel when the operating power is cut off, for example, in the case of a liquid crystal display driver, resulting in deterioration of the characteristics of the liquid crystal display element. For this purpose, initialization processing called display off sequence processing or the like is performed, such...

AI Technical Summary

Problems solved by technology

In Patent Document 2, it is considered that even if the above-mentioned response processing is intended to be started due to a drop in the voltage of the drive power supply, the response processing cannot be completed due to a drop in the logic power supply in the middle or before it.

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