Backlight chip and screen fill light circuit

Abstract

The invention provides a backlight chip and a screen supplementary light circuit, including: a logic control module, a current sampling / slope compensation circuit, an error amplifier, a compensation network module, a boost control logic module, a voltage selection module and a switch tube; the logic control module sends First, second and third logic control signals; when the current sampling / slope compensation circuit receives the first logic control signal, it outputs a compensated sampling current signal; the error amplifier adjusts the gain according to the second logic control signal, and outputs the adjusted gain And the first voltage signal determined by the reference voltage signal and the minimum voltage signal; the compensation network outputs the second voltage signal obtained after adjusting the capacitance multiplication factor according to the third logic control signal; the boost control logic module outputs the sampled current signal and the first voltage The duty cycle signal is obtained by signal comparison, and the switching tube is boosted according to the duty cycle signal. The backlight chip provided by the invention does not need an external capacitor, which reduces the area of ​​the chip and reduces the cost.

Description

technical field [0001] The invention relates to the technical field of integrated circuits, in particular to a backlight chip and a screen supplementary light circuit. Background technique [0002] With the continuous optimization of electronic devices, more and more electronic devices are equipped with various applications and accessories. For example, many electronic devices are equipped with cameras to meet the needs of users for taking pictures. With the improvement of camera performance, the function of taking pictures is becoming more and more perfect. For example, a flash is usually configured for the rear camera, and is used to compensate the light when the user takes pictures in a low-light environment, so as to obtain clear pictures. [0003] Compared with using the rear camera to take pictures, users prefer to use the front camera in the electronic device to take selfies. However, the front camera is not equipped with a fill light device, so when the user takes p...

AI Technical Summary

Problems solved by technology

[0003] Compared with using the rear camera to take pictures, users prefer to use the front camera in the electronic device to take selfies. However, the front camera is not equipped with a fill light device, so when the user takes pictures in an environment where the light is insufficient, the exposure will be insufficient. resulting in unclear photos

In order to solve the above problems, an external compensation capacitor is usually added outside the backlight chip of the electronic device, and the capacitance value of the added external compensation capacitor is usually large, and the external compensation capacitor has a large volume and needs to occupy a large area. Increase the area of ​​the PCB board where the backlight chip is located and the volume of the electronic equipment, and increase the application cost of the electronic equipment

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