Á½¼¶LCÂ˲¨Æ÷Éè¼Æ
05-08
• Á½¼¶Â˲¨Æ÷Éè¼ÆµÄһЩעÒâÊÂÏÒÔÇ°¶¼Ã»ÓйØ×¢¹ý£¬Ð´µÃ·Ç³£ºÃ¡£Á½¼¶LCÂ˲¨Æ÷µÄDesign Rules ³Ï·Ò룬Ïêϸ¿´Ô°æ¡£
• Design Rule #1:Don't think of the filter as ¡°Main filter followed by Noise filter¡±, that can get your design in trouble. It's an integral filter which you won't separate that way when you design it properly.
• ¹æÔò1£º²»Òª½«Â˲¨Æ÷¿´³ÉÊÇ¡°Ò»¸öÖ÷Â˲¨Æ÷ºó¸úËæÒ»¸öÔëÉùÂ˲¨Æ÷¡±£¬Õâ»á¸øÄãµÄÉè¼Æ´øÀ´Âé·³¡£ÄãÏëÕýÈ·Éè¼Æ¾Í²»Äܽ«Â˲¨Æ÷Ç°ºó¼¶·Ö¿ª¿´´ý£¬ËüÊÇÒ»¸öÍêÕûµÄÂ˲¨Æ÷¡£
• Design Rule #2: Make the first capacitor the smaller of the two. Then you'll have a second filter resonance which is fixed¡ª it won't be affected by capacitive loading. Typically, the first capacitor will be 2-20 times smaller than the output capacitor.
• ¹æÔò2£ºÇ°¼¶µçÈݱȺ󼶵çÈÝС¡£ÕâÑùµÄÂ˲¨Æ÷Á½¸öгÕñµã¹Ì¶¨£¬¶ø²»»á±»ÈÝÐÔ¸ºÔظı䡣ǰ¼¶µçÈݵĵäÐÍÖµ±ÈÊä³öµçÈÝС2-20±¶¡£
• Design Rule #3: Make the second inductor much smaller than the first¡ª typically about 10% of the main inductor value.
• ¹æÔò3£ºÊ¹µÚ¶þ¸öµç¸Ð±ÈµÚÒ»¸öµç¸ÐСºÜ¶à£¬µäÐÍֵΪǰ¼¶Ö÷µç¸ÐµÄ10%¡£
• Design Rule #4: Put the second filter resonance about 3 times higher than the loop crossover frequency.
• ¹æÔò4£ºÊǵڶþ¼¶Â˲¨Æ÷гÕñƵÂÊ´ó¸ÅΪ»·Â·´©Ô½ÆµÂʵÄ3±¶¡£
• Design Rule #5: Damp the second filter resonance properly. That means carefully choosing the ESR of the second inductor and the filter capacitors.
• ¹æÔò5£º´Î¼¶Â˲¨Æ÷гÕñ×èÄáÊʵ±¡£ÕâÒâζ×ÅÐèҪСÐÄÑ¡È¡´Î¼¶µç¸ÐºÍÁ½¸öµçÈݵĵÈЧ´®Áª×迹(ESR)Öµ¡£
• Design Rule #1:Don't think of the filter as ¡°Main filter followed by Noise filter¡±, that can get your design in trouble. It's an integral filter which you won't separate that way when you design it properly.
• ¹æÔò1£º²»Òª½«Â˲¨Æ÷¿´³ÉÊÇ¡°Ò»¸öÖ÷Â˲¨Æ÷ºó¸úËæÒ»¸öÔëÉùÂ˲¨Æ÷¡±£¬Õâ»á¸øÄãµÄÉè¼Æ´øÀ´Âé·³¡£ÄãÏëÕýÈ·Éè¼Æ¾Í²»Äܽ«Â˲¨Æ÷Ç°ºó¼¶·Ö¿ª¿´´ý£¬ËüÊÇÒ»¸öÍêÕûµÄÂ˲¨Æ÷¡£
• Design Rule #2: Make the first capacitor the smaller of the two. Then you'll have a second filter resonance which is fixed¡ª it won't be affected by capacitive loading. Typically, the first capacitor will be 2-20 times smaller than the output capacitor.
• ¹æÔò2£ºÇ°¼¶µçÈݱȺ󼶵çÈÝС¡£ÕâÑùµÄÂ˲¨Æ÷Á½¸öгÕñµã¹Ì¶¨£¬¶ø²»»á±»ÈÝÐÔ¸ºÔظı䡣ǰ¼¶µçÈݵĵäÐÍÖµ±ÈÊä³öµçÈÝС2-20±¶¡£
• Design Rule #3: Make the second inductor much smaller than the first¡ª typically about 10% of the main inductor value.
• ¹æÔò3£ºÊ¹µÚ¶þ¸öµç¸Ð±ÈµÚÒ»¸öµç¸ÐСºÜ¶à£¬µäÐÍֵΪǰ¼¶Ö÷µç¸ÐµÄ10%¡£
• Design Rule #4: Put the second filter resonance about 3 times higher than the loop crossover frequency.
• ¹æÔò4£ºÊǵڶþ¼¶Â˲¨Æ÷гÕñƵÂÊ´ó¸ÅΪ»·Â·´©Ô½ÆµÂʵÄ3±¶¡£
• Design Rule #5: Damp the second filter resonance properly. That means carefully choosing the ESR of the second inductor and the filter capacitors.
• ¹æÔò5£º´Î¼¶Â˲¨Æ÷гÕñ×èÄáÊʵ±¡£ÕâÒâζ×ÅÐèҪСÐÄÑ¡È¡´Î¼¶µç¸ÐºÍÁ½¸öµçÈݵĵÈЧ´®Áª×迹(ESR)Öµ¡£
Ïà¹ØÎÄÕ£º
- Â˲¨Æ÷Éè¼ÆµÄ³£¹æ (05-08)
- ¶Ì·֦½Ú³¬¿í´ø´øͨÂ˲¨Æ÷Éè¼Æ£¬ÔËÓÃAWR (05-08)
- LCºÏ·Æ÷Çë´óÏÀÖ¸µã (05-08)
- MWOÔÚÓÃlcÉè¼ÆÁËÒ»¸ö´øͨÂ˲¨Æ÷ÒÔºóÔõôµÃµ½pcb°æͼ (05-08)
ÉäƵרҵÅàѵ½Ì³ÌÍƼö
- ¸ß¼¶ÉäƵ¹¤³ÌʦÑø³ÉÅàѵ½Ì³ÌÌ××°
- È«·½Î»Ñ§Ï°ÉäƵרҵ֪ʶ£¬ÌáÉýÑз¢¹¤×÷ÄÜÁ¦£¬ÖúÄú¿ìËٳɳ¤ÎªÓÅÐãµÄÉäƵ¹¤³Ìʦ...
- Öм¶ÉäƵ¹¤³ÌʦÑø³ÉÅàѵ½Ì³ÌÌ××°
- ¾«Ñ¡30¶àÃÅÉäƵÅàѵ¿Î³Ì£¬×¨¼ÒÊڿΣ¬ÖúѧԱ¿ìËÙ´ïµ½Ò»¸öºÏ¸ñÉäƵ¹¤³ÌʦµÄÒªÇó...