学习了,谢谢
1871啊…难度还中啊…我用风枪差点没把手给烤了…-_-b
抢在天狼前问你:“不要松香和焊锡?”{:1_217:}
ckvlhf 发表于 2009-7-7 21:40 http://shoudian.org/images/common/back.gif
板子上的喷锡够了。烙铁只起加热作用,不用松香{:1_246:}
资料详细。支持一下
1871啊…难度还中啊…
本来想写高的,后来想想比1700简单不少。。。有空改成高吧{:1_217:}
顶YZX……收藏慢读……
有了方针目标和行动指南了,点亮一盏明灯,照亮。。。。。。。。。
这个要支持!
待机模式 不叫(跳周期) 应该是PFM模式,或者你写个skipping,跳周期有点那个意思。没听过啊~~孤陋寡闻了~~
{:1_251:}TPS申请不到
看来还是1700好,MAX1703也不错
好贴要顶
待机模式 不叫(跳周期) 应该是PFM模式,或者你写个skipping,跳周期有点那个意思。没听过啊~~孤陋寡闻了~~
不是FPM,实际61030工作波形,用最小的占空比连续工作10个周期左右,把电容的电充到5.2V左右,然后休眠
直到电容的电又降回5V,然后再触发工作,一般1秒触发一次,所以才能得到惊人的微功耗,uA表都很难测出!
LT和TPS的原始DataSheet都写的是跳周期,或是英文Burst Mode
Burst Mode Operation
The LTC1700 can be enabled to go into Burst Mode
operation at low load currents simply by connecting the
SYNC/MODE pin to a voltage of at least 1.2V. In this mode,
the peak current of the inductor is set as if VITH = 0.36V (at
low duty cycles) even though the voltage at the ITH pin is
actually at a lower value. If the inductor’s average current
is greater than the load requirement, the voltage at the ITH
pin will drop. When the ITH voltage goes below 0.12V, the
internal sleep signal goes low, turning off both external
MOSFETs. Now the load current will solely be supplied by
the output capacitor and the output voltage begins to
droop. This drooping of the output voltage results in the
rise of ITH voltage and once it has risen above 0.22V,
switching will then be resumed on the next oscillator cycle.
做移动电源给手机充电,倒底是1700好还是61030好{:1_256:}
给1个手机充电,MP3啥的充电,61030完胜
给3个以上手机同时充电,1700完胜
给牛逼的超级智能手机充电(电流大于2A那种),1700完胜
LM3668,TPS63000等等