We are meeting an application issue of HDC1080, different pull up resistors of SDA/SCL will result of different result. We tested the pull up resistor lower than 2.2Kohm, the communication is error with HDC1080. When changed to 10Kohm, the communication is correct with HDC1080....
In a word, the value of an I²C pull-up resistor must be large enough to reduce unnecessary current consumption and small enough to produce an acceptable rise time. Normally we would choose 10K or 4.7K for I2C pull up resistor, but for some special case we may adjust it smaller. Note...
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...
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...
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...
page 32 for the maximum and minimum rise time specifications. Optimum value of pull up resistor ...
Pullup resistor calculation for I2C A customer's design wants to adjust the pull_ups value for their I2C interface, how to decide to accept their change? Is there a correct resistance value for I2C pull-up resistors? I2C Bus Pullup Resistor Calculation by TI...
the value range of tr and tlow according to the line characteristics of an I2C bus working under a fast mode, and thereby work out the value range of R according to the value range and a calculation formula including the tr and tlow of the resistance R of an I2C pull-up resistor. Th...
Please refer to the NXP I2C Specifications, for choosing the correct pull up resistors based on your data rate, bus capacitance and VDD. These are the limiting factors here. In particular, refer to the Pull-up resistor sizing section from the document. Let us know your results! Happy to he...
Choosing Pullup Resistors I2C requires pullup resistors to provide a logic-high level to data and clock lines. There are tradeoffs between power dissipation and speed, and a compro- mise must be made in choosing pullup resistor values. Every device connected to the bus introduces some ...