Bi directional level conversion means that the chip can automatically adjust the level conversion according to the direction of the control signal. Of course, it corresponds to unidirectional level conversion, which requires a person to control the level conversion direction.

    Level conversion chips are often used in multi master and multi slave protocols, such as IIC and SMbus. Automatic bidirectional voltage converters are used because they can automatically detect the emission direction of devices and change the direction accordingly.

     TI‘s three automatic bidirectional voltage converter series: TXB, TXS and LSF. As can be seen from the figure below, the products of these three series are both complex and simple. The pins of TXB and TXS are identical, but LSF is slightly different.

    These three series can automatically detect direction in bidirectional voltage level conversion applications. The LSF series has the highest data rate of 200 megabits per second. The data rate of TXB is in the middle. TXS is usually used for slow applications. LSF and TXS can be flexibly used for open drain and push-pull interfaces. The TXB can only be used with push-pull drives. The LSF utilizes a switch based passive signal. TXS is similar to LSF, but circuit is added to improve signal integrity. The TXB is similar to a buffer and has excellent signal integrity.

    For applications, such as IIC, TXB cannot be used to convert the level, but only TXS or LSF series can be selected.

    For the same product, there are many packaging forms of chips, which can be well applied to various occasions.