Input voltage rising time control circuit

Abstract

The invention provides an input voltage rising time control circuit. According to the input voltage rising time control circuit, a voltage control unit is arranged in a panel driving unit; the voltage control unit comprises a voltage rising slope detection unit, a first comparator, a second comparator, a control unit and a capacitor unit; the voltage rising slope detection unit is used for detecting a voltage rising slope of a second end of the capacitor unit and outputting to the first comparator and the second comparator; the first comparator and the second comparator are used for comparing the voltage rising slope with a first slope corresponding to pre-set minimum starting-up time and comparing the voltage rising slope with a second slope corresponding to pre-set maximum starting-up time; a control module is used for changing the capacitance of the capacitor unit according to a comparing result, so that the time of raising the voltage of the second end of the capacitor unit to input voltage is adjusted; the starting-up time of a control panel accords with a normal starting-up time range and the quality of a product is improved.

Description

technical field [0001] The invention relates to the technical field of integrated circuits, in particular to an input voltage rising time control circuit. Background technique [0002] With the development of display technology, liquid crystal displays (Liquid Crystal Display, LCD) and other flat display devices are widely used in mobile phones, televisions, personal Various consumer electronic products such as digital assistants, digital cameras, notebook computers, and desktop computers have become the mainstream of display devices. [0003] Most of the liquid crystal display devices currently on the market are backlight liquid crystal displays, which include a liquid crystal display panel and a backlight module (Backlight Module). The working principle of the liquid crystal display panel is to place liquid crystal molecules between two parallel glass substrates. There are many vertical and horizontal small wires between the two glass substrates. The direction of the liqu...

AI Technical Summary

Problems solved by technology

[0005] With the continuous improvement of consumers' requirements for product quality, the start-up time of the liquid crystal display panel has become one of the focuses of consumers, and the start-up time of the liquid crystal display panel is related to the rise time of the input voltage of the liquid crystal display panel (input voltage from zero to zero) When the rise time of the input voltage is too short, the inrush current (Inrush Current) will be too large, which will impact the integrated circuit on the panel and damage the integrated circuit. When the input voltage rises If the rise time is too long, it will lead to too long boot time and cause customer complaints, so usually the boot time of the LCD panel should be kept between 0.5ms and 10ms

like figure 1 As shown, it is an existing input voltage rise time control circuit, including: a core board 101, a panel drive unit 102 electrically connected to the core board 101, and the panel drive unit 102 is provided with parallel A plurality of capacitors C10, the first ends of the plurality of capacitors C10 are electrically connected to the core board 101, and the second ends are all grounded, and the core board 101 inputs a core board voltage Vin12 to the panel drive unit 102 Output an input voltage Vin1, control the rise time of the input voltage Vin1 by controlling the number of capacitors C10 in the panel drive unit 102, and then control the start-up time of the panel, the more the number of capacitors C10, the longer the rise time of the input voltage Vin1, and the start-up time of the panel The longer the capacitor C10 is, the smaller the number of capacitors C10 is, the shorter the rise time of the input voltage Vin1 is, and the shorter the start-up time of the panel is. This kind of input voltage rise time control circuit cannot guarantee that the panel drive unit 102 can be used with any specification of the core board 101. Make the power-on time of the panel between 0.5ms and 10ms, which will affect the product quality

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