What does the open drain mean in I2C bus?
You don’t WANT any of the devices to drive it high because that would completely preclude any communication on the bus. The devices can only communicate if they can pull the bus LOW so that all the other devices on the bus can recognize that activity is taking place. What does the open drain mean in plain English?
What does terminating I2C bus MEAN-Stack Exchange?
The termination resistors in the case of I2C are just the pullup resistors. You don’t need terminators in the normal transmission line meaning of the word, because the bus is very short compared to the operating bandwidth so reflections are not an issue.
How does the MCU work on an I2C bus?
The MCU is just another member of the bus like the rest of the Devices. There is nothing particularly special about how the MCU operates on the I2C bus. The MCU can recognize when either line is high or low, and the MCU can pull on either (or both) of the lines itself in order to communicate with all the other devices on the bus.
When was the I2C data transfer bus invented?
Inter-Integrated Circuit, known as I2C, I2C, or even IIC, is a two-wire data transfer bus. Philips Semiconductor (now NXP Semiconductors) invented the protocol in 1982, and it received widespread use in applications where low costs and ease-of-implementation take priority over lightning-quick speed.
Is there a low capacitance I2C bus cable?
Even though there might be low capacitance cables on the market there is not much one can do about this except to lower the speed and to possible use a lower bus termination. As a general rule, on low voltage I2C systems the cables should be kept as short as possible and ribbon cables are preferable.
What is the voltage of an open drain?
The open collector (BJT) or open drain (FET) is essentially a SPST switch connecting the IC pin to ground. If the switch is closed, then the voltage on the pin (and the I²C line) is about 0 volts. If any switches are closed (if any pins of any ICs are connected to the same SDA or SCL line), the voltage on the line is about 0 volts.
Do you need level shifting devices for I2C?
Since the I2C bus lines are used bidirectionally, interfacing I2C devices with different voltages is not straightforward, special level-shifting devices are necessary for this purpose. Things to consider when working with low voltage I2C systems.