Backlight LED driving chip and TD terminal

Abstract

The invention belongs to the technical field of light emitting diodes (LED), and discloses a backlight LED driving chip and a time division (TD) terminal. The backlight LED driving chip comprises a charge pump, wherein voltage doubling modes of the charge pump comprise the voltage doubling mode of less than 1.5X. A common anode of the 1.33X voltage doubling mode is adopted to output a plurality of paths of constant current sources so as to adjust the charge pump for backlight driving of a liquid crystal display (LCD) parallel white light; the backlight power consumption of the LCD parallel white light is reduced to be over 40mA; and thus the backlight power consumption is greatly reduced, and the utilization ratio of the power source is also improved.

Description

technical field [0001] The invention belongs to the technical field of LEDs, and in particular relates to a backlight LED driver chip and a TD terminal. Background technique [0002] A conventional liquid crystal display (Liquid Crystal Display, LCD) backlight is a white light emitting diode (Light Emitting Diode, LED), which requires a power supply voltage of about 3.2-3.6V to achieve proper brightness control. Among them, most of the LCD backlights below the 3” display screen use about 4 LED lights in parallel to emit light, and the display screens above the 3” screen generally use 6 or more LED lights in series to emit light due to the large screen area. Most mobile phones use lithium-ion batteries as power sources. Lithium-ion batteries are about 4.2 volts after being fully charged, and about 2.8 volts after safe discharge. The general shutdown voltage of mobile phones is about 3.3V. [0003] If the white LED is directly driven by the battery, the brightness of the LED ...

AI Technical Summary

Problems solved by technology

The advantage of this type of charge pump is that the current of each LED is constant and the LCD backlight is uniform; the disadvantage is that in the 1.5X and 2X modes, the constant current source of the charge pump will generate more useless heat loss, resulting in low efficiency

[0013] Because the higher the working voltage of the charge pump, the lower the efficiency, because the voltage drop of the LED is a fixed value. When the charge pump works at a higher double voltage value, the excess voltage drop will be lost in the constant current source and the series circuit.

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