你好，
根据参考设计的公式，IIC总线的上拉电阻范围由下面公式计算
我的问题是Rp(min)公式中的VCC，VOL,IOL是指那个芯片的电压和电流，MCU还是IIC芯片？是实测值还是手册的典型值或者最大值？
Cb是怎么得到的？是测量还是计算？
谢谢。
Translated to English:
Hello,
The pullup resistance range of the IIC bus is calculated from the following formula according to the reference design
My question is the VCC in the RP(min) formula, VOL,IOL refers to the voltage and current of that chip. MCU or IIC chip? Is it a measured value or a typical or maximum value in the manual?
How was CB obtained? Measure or Calculate?
Thanks.
Hi Chambin,
The output low level voltage (VOL) and output low-level current (IOL) is a characteristic of whichever I2C device is speaking at a particular moment, usually the I2C controller. You can find some of these electrical characteristics in the device data sheet. Usually, worst-case analysis is done using minimum and maximum values, as applicable.
The bus capacitance (CB) value can be estimated based on the characteristics of the bus plus loads attached to it, or it can be measured in application. Either way is valid.
Also, please note that we have a Chinese E2E forum located at e2echina.ti.com, where our experts can communicate in Chinese. This forum is mainly in English. 
Best,
Danny
