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PWM (Pulse Width Modulation) circuit and LED drive circuit

一种PWM电路、LED驱动的技术，应用在电光源、电气元件、产生电脉冲等方向，能够解决无法解决动态屏刷新率和解析度等问题，达到保持解析度、提高刷新频率的效果

Inactive Publication Date: 2012-08-08
SUPEC SUZHOU
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] In the dynamic scanning system, the display refresh frequency is required to be above 2KHz. Although the general PWM has a resolution of 16bit, affected by the GCLK frequency, the number of GCLKs required for a 16bitPWM to complete a pulse cycle is 2 16 = 65536, if the frequency of GCLK is 30MHz, then the length of a cycle of 16bitPWM is: 65536 / 30M = 2.19ms; the refresh frequency is 458Hz; if the dynamic scan is 4 sweeps, the refresh rate of the LED display is 458 / 4 = 114.5 Hz; in order to meet the requirements of practical applications and improve the dynamic refresh rate, only the cycle length of PWM can be reduced, that is, the bit length of PWM can be reduced. If the bit length of PWM is 12bit, the refresh rate can be 1824Hz; but the PWM bit length can be reduced long, the resolution will be reduced, and the contradiction between the refresh rate and resolution of the dynamic screen cannot be solved under the traditional solution

Method used

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  • PWM (Pulse Width Modulation) circuit and LED drive circuit
  • PWM (Pulse Width Modulation) circuit and LED drive circuit
  • PWM (Pulse Width Modulation) circuit and LED drive circuit

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Embodiment Construction

[0027] In order to enable those skilled in the art to better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described The embodiments are only some of the embodiments of the present application, but not all of them. Based on the embodiments in this application, all other embodiments obtained by persons of ordinary skill in the art without creative efforts shall fall within the scope of protection of this application.

[0028] The embodiment of the present application discloses a PWM circuit, including:

[0029] PWM counter for counting clock signals;

[0030] The reference value setting register is used to set a comparison reference value for determining the duty cycle of the PWM signal;

[0031] A frequency multiplier to increase the frequency of the...

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Abstract

The invention discloses a PWM (Pulse Width Modulation) circuit which comprises a PWM counter, a reference value setting register, a frequency multiplier and a comparator, wherein the frequency multiplier is used for increasing the frequency of a clock signal and outputting the frequency to the PWM counter. The invention also discloses an LED drive circuit. By increasing the frequency of the PWM input clock signal by N times through the frequency multiplier, the counting period of the PWM counter is shortened to 1 / N of the original period. In a dynamic LED display screen, the refreshing frequency can be increased by N times, and the original resolution can be maintained.

Description

technical field [0001] The application belongs to the field of LED display screens, and in particular relates to a PWM circuit and an LED driving circuit. Background technique [0002] Pulse Width Modulation (PWM) is a very effective technique for controlling analog circuits using the digital output of a microprocessor. It is widely used in many fields from measurement, communication to power control and conversion. [0003] ginseng figure 1 As shown, in the prior art, the PWM circuit 10 generally includes: a PWM counter 11, which is used to perform up / down counting of the clock signal; a reference value setting register 12, which is used to set the duty cycle (duty cycle) comparison reference value; the comparator 13 is used to compare the count value of the PWM counter with the comparison reference value of the reference value setting register, and generate an effective PWM signal. [0004] In the LED display, in order to improve the display resolution, PWM technology is...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H03K3/017G09G3/32H05B44/00
CPCH03K3/017H03K7/08H05B45/325H05B47/16Y02B20/30
Inventor 范立新
Owner SUPEC SUZHOU
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