A control method for line scan chip for improving plasma display emi low frequency exceeding standard

Abstract

The invention provides a technical scheme related to a row scanning chip control method for improving plasma display EMI low frequency excess. According to the scheme, packet control performed on the output end of a row scanning chip is used, meanwhile, a clamper tube and a PN junction capacitor are added to the input end of a low-voltage tube, and therefore EMI radiation caused by high voltage power supply large current brought by punchthrough can be effectively reduced in a high-voltage concurrent movement process of the row scanning chip.

Description

technical field [0001] The present invention relates to a control method for reducing the influence of display low-frequency radiation, especially a control method for row-scanning chips to improve plasma display EMI low-frequency exceeding the standard. Background technique [0002] In the prior art, the known technology is that in the three-electrode driven plasma display module, the PDP line scanning chip is used to drive the Y electrodes of the display unit of the plasma module, and output addressing high-voltage pulses. Cooperate with the addressing A electrode in rows or interlaced rows to form a voltage greater than 200V to discharge the display unit to obtain wall charges, and then conduct cyclic discharge through the X and Y electrodes to form a certain duration to determine the gray level, through the gray level and silver light The color combination of powder forms a colorful picture. [0003] Taking a plasma display with 768 lines as an example, 8 line scanning ...

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Problems solved by technology

If the high voltages of 768 lines are all converted from low level to high level during concurrent actions, the superposition of about 300mA current in each line will result in a current of about 230A. If the output of the line scanning chip is not controlled concurrently, it will be impossible. Realize the high-voltage concurrent operation of the line scanning chip; since the output stage of the line scanning chip uses LIGBT (Lateral Insulated Gate Bipolar Transistor), the closing process is much slower than the opening process due to the high minority carrier injection concentration of LIGBT itself during the closing process , the turn-on process of the power tube is affected by the driving ability of its gate electrode. The gate of the power tube can be regarded as a capacitor. When the charge reaches the threshold voltage, the channel region of the power tube is opened, and the current at the moment of turn-on is relatively large. Its di / dt can cause serious EMI problem, and this is the deficiency that existing technology exists

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