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ina303a1拉低基准

原理图如上,外围电路什么都没接的情况下给ref供2.5v电压,电流20ma以上,2.5v和5v同时供的情况下,工作一会以后2.5v工作电流会跳变

user5992955:

器件为INA303A1pwr

user5992955:

器件为INA303A1pwr

Kailyn Chen:

参考电流如何跳变的? 2.5V电压降低了是吗?

user5992955:

回复 Kailyn Chen:

如果通过基准供电,电压会被拉低。视频是通过稳压电源供电单击此处播放此视频
(function(id)
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})('v_e6d6851e83044d7d8ea3468e93e7e60f');

user5992955:

回复 user5992955:

单击此处播放此视频
(function(id)
{var v = document.getElementById(id), isSafari = navigator.userAgent.indexOf(‘Safari’) != -1 && navigator.userAgent.indexOf(‘Chrome’) == -1;var op = v.style.position, ol = v.style.left, or = v.style.right, fe = [];var nodeLimit = 50;checkVideo = function() {if (!v.canPlayType || v.error) {var bound = 0;while (v.childNodes.length > 0 && bound 0 && bound < nodeLimit) {bound++;if (v.childNodes[0].nodeName != 'SOURCE') {fe[fe.length] = v.childNodes[0];v.parentNode.insertBefore(v.childNodes[0], v);}}window.setTimeout(checkVideoRendered, 249);} else if (v.readyState == 0) {window.setTimeout(checkVideo, 249);}},checkVideoRendered = function() {if (v.networkState == 1 && v.readyState == 4) {v.style.position = op;v.style.left = ol;v.style.right = or;for (var i = 0; i < fe.length; i++) {fe[i].parentNode.removeChild(fe[i]);}} else {window.setTimeout(checkVideoRendered, 249);}}if (navigator.userAgent.indexOf('iPad') == -1 && navigator.userAgent.indexOf('iPhone') == -1 && navigator.userAgent.indexOf('iPod') == -1) {window.setTimeout(checkVideo, 249);}
})('v_cdf0952cbe6e48559122912d3d83803f');

user5992955:

回复 user5992955:

而且有时候很奇怪,只有一路的时候刚开始还是正常的,当接上两路或者三路的时候电流跳变更快

Kailyn Chen:

回复 user5992955:

电压被拉低,应该是电路哪里耗电,导致电压被拉低。没有输入,那么静态电流正常吗,会不会比datasheet中的值高?
或者您把输出端的容性负载C38去掉试试呢? 我担心是由于layout中的寄生电感和电容组成了LC 滤波电路,导致功耗增加。

user5992955:

回复 Kailyn Chen:

目前是只有焊接ina303和主芯片,其他都是空着。单单对ina303供5v主电源,5v电流是正常的。如果把2.5v基准也供进去,2.5v基准电流就出现异常。5v主供电没给的情况下,只给2.5v基准,2.5v电源的电流也会异常。
目前等待官方评估版到货后再验证下

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