Unlock instant, AI-driven research and patent intelligence for your innovation.

A PWM dimming control method, a control circuit and an LED drive circuit using the same

A dimming control circuit and dimming control technology, applied in the electronic field, can solve the problems of LED current distortion, short effective width time, inaccurate average current, etc., and achieve the effect of simple control circuit, easy control circuit and good effect.

Active Publication Date: 2015-11-25
SILERGY SEMICON TECH (HANGZHOU) CO LTD
View PDF7 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, if the effective width of the PWM dimming signal is very short, such as Figure 1B Another PWM dimming waveform diagram in the prior art, because the effective width time of the PWM dimming signal is very short, the LED current is distorted, resulting in inaccurate average current

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • A PWM dimming control method, a control circuit and an LED drive circuit using the same
  • A PWM dimming control method, a control circuit and an LED drive circuit using the same
  • A PWM dimming control method, a control circuit and an LED drive circuit using the same

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0030] Several preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, but the present invention is not limited to these embodiments. The present invention covers any alternatives, modifications, equivalent methods and schemes made on the spirit and scope of the present invention. In order to provide the public with a thorough understanding of the present invention, specific details are set forth in the following preferred embodiments of the present invention, but those skilled in the art can fully understand the present invention without the description of these details.

[0031] refer to figure 2 , is shown as a circuit block diagram of an embodiment of the PWM dimming control circuit according to the present invention, as figure 2 As shown, the input power drives the LED load through the power stage circuit 205, and the power stage circuit includes a power switch tube (not shown) for controlling energy...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

In one embodiment, a pulse-width modulation (PWM) dimming control method for a light-emitting diode (LED) load, can include: (i) receiving a PWM dimming signal and a clock signal in a control circuit, where the clock signal is used to determine an effective width of the PWM dimming signal; (ii) setting a minimum value of the effective width of the PWM dimming signal; (iii) using the PWM dimming signal as a dimming control signal when the effective width of the PWM dimming signal is greater than the minimum value; (iv) regulating the effective width of the PWM dimming signal as the minimum value, and using the regulated PWM dimming signal as the dimming control signal, when the effective width of the PWM dimming signal is less than the minimum value; and (v) controlling a driving current of the LED load according to the dimming control signal.

Description

technical field [0001] The present invention relates to the field of electronic technology, and more specifically, relates to a novel PWM dimming control method and a control circuit. Background technique [0002] LED backlights are widely used due to their energy saving, environmental protection, light and thin size, etc., but LEDs need a driving circuit that can provide a constant current and a dimming circuit that can adjust their brightness during use. At present, LED dimming technology mainly includes analog dimming and PWM dimming. Among them, PWM dimming has more accurate precision and is widely used in switching power supplies. PWM dimming adjusts the average value of LED current by setting the period and duty cycle. [0003] As we all know, when the LED load is powered on, a large inrush current is often generated, and the magnitude of the inrush current is greater than the driving current value of the LED load, such as Figure 1A In the PWM dimming waveform diagram...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Patents(China)
IPC IPC(8): H05B37/02H05B44/00
CPCH05B33/0815H05B33/0818H05B33/0845Y02B20/42H05B45/3725H05B45/10Y02B20/40
Inventor 张凌栋
Owner SILERGY SEMICON TECH (HANGZHOU) CO LTD