LED恒流驱动应用-L5973系列应用讨论

ST L5973AD 定频500KHz
ST L5973D 定频250KHz

我用L5973D做恒流输出0.35A,阳极BUCK-BOOST回路,输入电压8V-24V,输出9V-15V.发现该芯片很容易震荡,工作不稳定,发热比较严重.后经过调整输出电流波形已基本稳定,但IC发热仍严重,不知道有没有曾经做过的朋友能不吝赐教.谢谢!
PS.附件的文档是原理图和12VDC输入时9V,12V,15V输出的电流波形.现在的工作状态基本正常,但IC仍有近60多度的温升.

864521190102339.doc

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yzx82322

LV.1

2007-09-19 09:18

自己顶一下,有没有用这块芯片做过恒流BUCK-BOOST的高手出来指导一下.
顺便把波形图重新贴一下,这次加入了OUT脚的输出波形.
12Vin-9Vout-Iout waveform

500) {this.resized=true; this.width=500; this.alt='这是一张缩略图，点击可放大。\n按住CTRL，滚动鼠标滚轮可自由缩放';this.style.cursor='hand'}" onclick="if(!this.resized) {return true;} else {window.open('http://u.dianyuan.com/bbs/u/57/864521190164567.jpg');}" onmousewheel="return imgzoom(this);">
12Vin-9Vout-PinOUT waveform

500) {this.resized=true; this.width=500; this.alt='这是一张缩略图，点击可放大。\n按住CTRL，滚动鼠标滚轮可自由缩放';this.style.cursor='hand'}" onclick="if(!this.resized) {return true;} else {window.open('http://u.dianyuan.com/bbs/u/57/864521190164578.jpg');}" onmousewheel="return imgzoom(this);">
12Vin-12Vout-Iout waveform

500) {this.resized=true; this.width=500; this.alt='这是一张缩略图，点击可放大。\n按住CTRL，滚动鼠标滚轮可自由缩放';this.style.cursor='hand'}" onclick="if(!this.resized) {return true;} else {window.open('http://u.dianyuan.com/bbs/u/57/864521190164625.jpg');}" onmousewheel="return imgzoom(this);">
12Vin-12Vout-PinOUT waveform

500) {this.resized=true; this.width=500; this.alt='这是一张缩略图，点击可放大。\n按住CTRL，滚动鼠标滚轮可自由缩放';this.style.cursor='hand'}" onclick="if(!this.resized) {return true;} else {window.open('http://u.dianyuan.com/bbs/u/57/864521190164648.jpg');}" onmousewheel="return imgzoom(this);">
12Vin-15Vout-Iout waveform

500) {this.resized=true; this.width=500; this.alt='这是一张缩略图，点击可放大。\n按住CTRL，滚动鼠标滚轮可自由缩放';this.style.cursor='hand'}" onclick="if(!this.resized) {return true;} else {window.open('http://u.dianyuan.com/bbs/u/57/864521190164670.jpg');}" onmousewheel="return imgzoom(this);">
12Vin-15Vout-PinOUT waveform

yzx82322

LV.1

2007-09-20 12:06

@yzx82322

自己顶一下,有没有用这块芯片做过恒流BUCK-BOOST的高手出来指导一下.顺便把波形图重新贴一下,这次加入了OUT脚的输出波形.12Vin-9Vout-Ioutwaveform[图片]500){this.resized=true;this.width=500;this.alt='这是一张缩略图，点击可放大。\n按住CTRL，滚动鼠标滚轮可自由缩放';this.style.cursor='hand'}"onclick="if(!this.resized){returntrue;}else{window.open('http://u.dianyuan.com/bbs/u/57/864521190164567.jpg');}"onmousewheel="returnimgzoom(this);">12Vin-9Vout-PinOUTwaveform[图片]500){this.resized=true;this.width=500;this.alt='这是一张缩略图，点击可放大。\n按住CTRL，滚动鼠标滚轮可自由缩放';this.style.cursor='hand'}"onclick="if(!this.resized){returntrue;}else{window.open('http://u.dianyuan.com/bbs/u/57/864521190164578.jpg');}"onmousewheel="returnimgzoom(this);">12Vin-12Vout-Ioutwaveform[图片]500){this.resized=true;this.width=500;this.alt='这是一张缩略图，点击可放大。\n按住CTRL，滚动鼠标滚轮可自由缩放';this.style.cursor='hand'}"onclick="if(!this.resized){returntrue;}else{window.open('http://u.dianyuan.com/bbs/u/57/864521190164625.jpg');}"onmousewheel="returnimgzoom(this);">12Vin-12Vout-PinOUTwaveform[图片]500){this.resized=true;this.width=500;this.alt='这是一张缩略图，点击可放大。\n按住CTRL，滚动鼠标滚轮可自由缩放';this.style.cursor='hand'}"onclick="if(!this.resized){returntrue;}else{window.open('http://u.dianyuan.com/bbs/u/57/864521190164648.jpg');}"onmousewheel="returnimgzoom(this);">12Vin-15Vout-Ioutwaveform[图片]500){this.resized=true;this.width=500;this.alt='这是一张缩略图，点击可放大。\n按住CTRL，滚动鼠标滚轮可自由缩放';this.style.cursor='hand'}"onclick="if(!this.resized){returntrue;}else{window.open('http://u.dianyuan.com/bbs/u/57/864521190164670.jpg');}"onmousewheel="returnimgzoom(this);">12Vin-15Vout-PinOUTwaveform[图片]500){this.resized=true;this.width=500;this.alt='这是一张缩略图，点击可放大。\n按住CTRL，滚动鼠标滚轮可自由缩放';this.style.cursor='hand'}"onclick="if(!this.resized){returntrue;}else{window.open('http://u.dianyuan.com/bbs/u/57/864521190164697.jpg');}"onmousewheel="returnimgzoom(this);">

有人做过的么?我顶.