UC3875出现的驱动异常问题,请各位分析,解释

我用UC3875做控制,驱动直接采用驱动变压器,图1是没加MOSFET时驱动变压器一个副边的驱动波形,但是驱动MOSFET时,测得的驱动波形如图2很怪,不知是怎么回事.我感觉是不是死区太小,刚刚测得的波形更不稳定,有时候正半周也出现两个波峰,还夹杂着相反方向的电压过冲,自藕调压器8A的保险丝总是烧,我怀疑是直通了.请各位帮忙分析,解释一下.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/57/931831190771068.bmp');}" onmousewheel="return imgzoom(this);">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/57/931831190771173.bmp');}" onmousewheel="return imgzoom(this);">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/57/931831190786085.png?x-oss-process=image/watermark,g_center,image_YXJ0aWNsZS9wdWJsaWMvd2F0ZXJtYXJrLnBuZz94LW9zcy1wcm9jZXNzPWltYWdlL3Jlc2l6ZSxQXzQwCg,t_20');}" onmousewheel="return imgzoom(this);">