SCPS274B June 2021 – March 2023 TCA39306
PRODUCTION DATA
As with the standard I2C system, pullup resistors are required to provide the logic-high levels on the translator bus. The size of these pullup resistors depends on the system, but each side of the repeater must have a pullup resistor. The device is designed to work with standard-mode and fast-mode I2C devices in addition to SMBus devices. Standard-mode I2C devices only specify 3 mA in a generic I2C system where standard-mode devices and multiple controllers are possible. Under certain conditions, high termination currents can be used. When the SDA1 or SDA2 port is low, the clamp is in the ON state, and a low-resistance connection exists between the SDA1 and SDA2 ports. Assuming the higher voltage is on the SDA2 port when the SDA2 port is high, the voltage on the SDA1 port is limited to the voltage set by VREF1. When the SDA1 port is high, the SDA2 port is pulled to the pullup supply voltage of the drain (VDPU) by the pullup resistors. This functionality allows a seamless translation between higher and lower voltages selected by the user, without the need for directional control. The SCL1-SCL2 channel also functions in the same way as the SDA1-SDA2 channel.