Discharge circuit, power supply and display device

Abstract

The application discloses a discharge circuit, a power supply and a display device. The discharge circuit includes: a voltage divider circuit, used to provide a control signal according to the driving signal; a first resistor, used to receive the input power; and a switch tube, the control end of the switch tube receives the control signal, and the first channel end is connected to the first resistor , the second access end is connected to the reference ground, and the switch tube is used to provide a discharge path from the input power to the reference ground according to the control signal, wherein the resistance value of the first resistor is selected according to the expected discharge time of the input power, and the driving signal is on The voltage value in the power state is less than or equal to zero, and rises when the power is off to make the control signal turn on the switch tube. The discharge circuit provides a discharge path from the input power to the reference ground, and controls the discharge time of the input power by controlling the size of the first resistor, so that the input power can be quickly discharged, the stability of the load is improved, and the problem of afterimage after shutdown is avoided.

Description

technical field [0001] The present invention relates to the field of display technology, and more specifically, to a discharge circuit, a power supply and a display device. Background technique [0002] With the popularity of electronic products, power supplies are used in various electronic products. The response time of the power supply is an important parameter. For example, the Video Electronics Standards Association (VESA) standard requires that the power-off time of the display device be controlled within 10 ms, so as to effectively eliminate afterimages. [0003] In the existing technology, such as figure 1 As shown, the power supply 100 includes a power management circuit 110 and a level conversion circuit 120. The power management circuit 110 is used to receive the logic power Vin and provide the initial signal VGL_P required by the load. The level conversion circuit 120 provides the power management circuit 110 with The initial signal is level converted to obtain...

AI Technical Summary

Problems solved by technology

However, in the actual working process of the power supply, the process of converting the logic power supply Vin from high level to low level takes a certain amount of time, such as Figure 2a As shown, the charge on the equivalent capacitance C of the power supply is released to the reference ground through the circuit resistance R0, and the discharge path is shown in the direction of the arrow in the figure

Figure 2b Taking the power supply of the liquid crystal display module as an example, the discharge sequence diagram of the power supply is shown. The discharge time Δt required for the logic power supply Vin to discharge from 0.9Vin to 0.1Vin is about 470ms, and the discharge time Δt is much greater than the 10ms required by the VESA standard. If the time is too long, and the discharge time is uncontrollable, it will easily cause problems such as after-image after shutdown and reduced load stability.

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