Hi Mark, The maximum value for an I2C pull-up resistor is limited by the line capacitance of the system to ensure the rise time of the signal can support the desired data rate. The first document here calculates the worst-case bus load of 400pF (max allowed by I2C spec), and th...
Other Parts Discussed in Thread:TUSB8020B 请注意,本文内容源自机器翻译,可能存在语法或其它翻译错误,仅供参考。如需获取准确内容,请参阅链接中的英语原文或自行翻译。 https://e2e.ti.com/support/interface-group/interface/f/interface-forum/625426/tusb8020b-i2c-to-flash-pull-up-resistor-value-...
page 32 for the maximum and minimum rise time specifications. Optimum value of pull up resistor ...
So, in this case the calculation is(5.0V – 0.4V) / .003A = 1533Ω. That represents the lowest possible pullup resistor value, commonly designated RPyou can use, because anything less would burn out your I2C pins. The value of the resistor would be larger with a smaller IOL, so the...
4 Example For Fast-mode I2C communication with the following parameters, calculate the pullup resistor value. Cb = 200 pF, VCC = 3.3 V Solution: Taking the values from Table 1: ( ( ) )RP(max) = tr (0.8473 ´ Cb ) = 300 ´10-9 0.8473 ´ 200 ´10-12 = 1.77 kW ( )RP...
Figure 1: Figures for finding pull-up resistor values from NXP spec UM10204 From Fig 41 (in figure 1 above) we can find the maximum pull-up value based on the speed and bus capacitance. You can see that lower bus capacitance means you can use larger resisto...
上述推导过程可以参考 TI的文档《I2C Bus Pullup Resistor Calculation》https://www.ti.com/lit/an/slva689/slva689.pdf 最终在调试的时候,当我们测量SDA或SCL信号并且逻辑LOW上的电压高于0.4V时,我们就知道可以知道灌电流太高了; 当然,这并不意味着每当灌电流超过3mA时,设备就会立即停止工作。但是,在操作超出...
Perhaps, the internal pull-up resistor value = 2k2Ω is affected to the baud rate in the second situation. In the second situation, Could you try to re-test using the resistor value = 200Ω or 10KΩ pull-up VDD for both SDA and SCL? Best regards, Dan 0 Kudos Reply 11-24-...
If I see significant unexpected rounding, I will then go back to first principles (Khan Academy: RC Step Response and Wikipedia: RC time constant) calculate RC, AKA Tau, (the time for rise from 10% to 90% divided by 2.2) followed by dividing by the pull up resistor value. I know i...
122 Rise and fall time parameters vary depending on external factors such as the characteristics of the I/O driver, pull-up resistor value, and total capacitance on the transmission line. HPS Ethernet Media Access Controller (EMAC) Timing Characteristics HPS NAND Timing Characteristics ...