Small-area power tube-based low-mismatching multi-channel light-emitting diode (LED) constant current source driving circuit

A driving circuit and constant current source technology, which is applied in the field of low-mismatch multi-channel LED constant current source drive circuit structure, can solve problems such as copy mismatch of different channels

Inactive Publication Date: 2011-06-15
PEKING UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] The present invention proposes a low-mismatch multi-channel LED constant current source drive circuit structure based on small-area power tubes

Method used

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  • Small-area power tube-based low-mismatching multi-channel light-emitting diode (LED) constant current source driving circuit
  • Small-area power tube-based low-mismatching multi-channel light-emitting diode (LED) constant current source driving circuit
  • Small-area power tube-based low-mismatching multi-channel light-emitting diode (LED) constant current source driving circuit

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Embodiment Construction

[0016] The technical solutions of the present invention will be further described in detail through specific embodiments below in conjunction with the accompanying drawings.

[0017] figure 2 For the concrete circuit diagram of the structural embodiment that the present invention proposes, as figure 2 As shown, the structure gives a schematic diagram of the two channels. IDGen generates ID, and the current mirror generates Iref, which is provided to different channels. In order to make the replication more accurate and make the power tube work in the linear region, its mismatch is given by the following formula:

[0018] ΔIout Iout = Δ ( W L ) ( W L ) + Δ ( ...

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Abstract

The invention provides a small-area power tube-based low-mismatching multi-channel light-emitting diode (LED) constant current source driving circuit structure, and belongs to the technical field of microelectronics and LED driving. The LED constant current source driving circuit comprises an identity (ID) generation module IDGen, a current mirror and n channels, wherein the ID generation module comprises an operational amplifier and a metal oxide semiconductor (MOS) tube; the current ID of the current mirror generates n equal currents Iref1, Iref2, ..., and Irefn; the n channels have a uniform structure and comprise an operational amplifier and two MOS tubes; and one MOS tube is a power tube, and the width to length ratio of the power tube is m times that of the other MOS tube. The matching design can be performed on the layout so as to reduce mismatching to the minimum extent.

Description

technical field [0001] The invention relates to a low-mismatch multi-channel LED constant current source drive circuit structure based on a small-area power tube, belonging to the technical fields of microelectronics and LED drive. Background technique [0002] With the large-scale application of LED screens, low mismatch and small-area LED drive circuits play a very important role in reducing costs, improving LED screen life and LED screen display quality. Due to the light-emitting characteristics of the LED lamp, a small change in the voltage at both ends can cause a drastic change in the current on it, so a constant current drive is required. In order to obtain the brightness consistency of different pixels, the current between different pixels should be as equal as possible. Moreover, due to the inconsistency between different LED lamp tubes, if the current mismatch between different LEDs is too large, the life of the LEDs may be affected. [0003] A typical LED drive ...

Claims

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Application Information

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IPC IPC(8): H05B37/02
Inventor 鲁文高王钊黄泽陈鸣尹航张雅聪陈中建吉利久
Owner PEKING UNIV
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