TI中文支持网Part Number:ISO1540
当前测试ISO1540 可以带到最长 16m, SMBUS协议 烧录成功；
但是无意中，移除ISO1540 B-SIDE端 上拉电阻 SMBC/SMBC 1Kohm 后；可以带到最长 25.2m, SMBUS协议 烧录成功；
本意用逻辑分析仪查看，但目前 尚无法找到原因？
通讯线材 AFS铁氟龙耐高温线材 2芯双绞 0.2平方毫米；长度测试如下 表格；
Taylor：
您好，
已经收到了您的案例，调查需要些时间，感谢您的耐心等待。
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Mike Jin：
I am not sure why B side removed 1kohm would enhance communicaiton capacity?
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Vivian Gao：
The way to calculate the Rpu value would be to use essentially ohm's law, V=IR. V = VCC, I = Io (output current), and R = Rpu. The main paramter to be concerned about would be the output current, as the Rpu would have to be selected in such a way that does not violate the absolute maximum ratings (shown below). Considering this, please use the output current in recommended operating conditions to select an Rpu that is in accordance with recommended operating conditions and within absolute maximum ratings.
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Mike Jin：
Thank Vivian for your inputting data!
But I am confused why it can be enhanced the lenth to 25m if removed 3.2V B pull up R(1Kohm)?
Do you have some good comments for my study?
Or how to measure the relevant parameters?
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Vivian Gao：
We have no further suggestions or support
