I2c Pullup Resistor 33v

- October 03, 2018

I had no problems running it off of 33v although it may have shared the i2c bus with another sensor that probably had 10k pull up resistor. I2c devices have open drain drivers which only pull the scl and sda lines low to 0v.

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I dont think you need any other additional pull up resistors.

I2c pullup resistor 33v. If you are sure to disable pull up on arduino side you are safe as i2c works in open drain mode but the logic level high of arduino is about 32v so it would be unstable. Each i2c line should have a single pull up resistor. Make sure they pull up to 33v and not 5v.

An 18k resistor represents the largest resistor we could use for pullup resistors on the i2c and spi education shield because 18k would work for both buses no need to use two different values. A smaller resistor will. If you are using i2ct3 you might want to slow the i2c bus down.

My i2c communications need to be pulled up to 33v but i dont know what size pull up resistor i should be using. I2c bus pullup resistor calculation 3 speed versus power trade off once the minimum and maximum value of the pullup resistor has been selected the decision for the value of resistor can be made based on trade off between the speed and power budget. Pullup resistor for i2c hey i want your take on the need of pull up resistors for i2c communication with pic18f46j50is it sufficient that using internal pullups will do the job at both 400kbps and 100kbpsi would like your your view on that.

Ask question asked 4 years 11 months ago. Also make sure that each 5v part has a reasonable vih input voltage high threshold. If not how do you decide the value for pullup resistors then for i2c communication.

Rpmin 33v 099v 135ma 171 ohms this is the minimum pull up resistance for an i2c bus composed of efm8lb1 devices. Arduino and raspberry pi 5v33v i2c. Ive read other forum posts that suggest 27k ohm or 47k ohm but that only seem to allow the high to be at 33v and the low to be at 30v.

Lower than this and we cannot guarantee that the device can pull the i2c bus lines below v ol. But im pretty sure i tested first wo anything else connected. Conversely a 1k5 resistor is the smallest value we could use without burning up the i2c pins of our devices.

Arduino and raspberry pi initiate i2c communication as slave. Many 5v chips use ttl vih which is 20v which works.