TXB0106 Drive strength

Hello Sushruta,

Thanks for the question.

The TXB device has a 4K series resistor, which limits the drive strength of the translator. This translator was designed for use with small loads of about 20 uA.

Would you mind sharing what you are trying to do with the device and for what interface? If you need something that can drive a slightly larger load, and still be auto bi directional, I would suggest looking at our TXS family.

Could you please suggest any auto bi directional translator in between 12 to 16 mA drive strength?

Thanks
Sushruta

Hello Sushruta,

An auto direction sensing translator will have a weaker drive strength. This is due to the requirements in order to make it auto direction sensing. If the driver is too strong, the device connected won't be able to over come the drive strength to force its own signal onto the bus. The translators look for their drive strength being overcome by a device and use that to detect which side is propagating to the other.

However, our TXS series offers rise time accelerators to make it behave like it has a stronger drive strength, while the static drive strength is much lower (~1mA) and allows for the part to be used as an I2C translator.

We do not have a TXS0106, but we do have a TXS0108, which features edge accelerators for both rising and falling.

I'm not sure what interface you're using this for, or what speeds you're looking at.

Hello Jonathan

We are using TXB0106  in between Xilinx FPGA Zynq IO pins and external interface.

I understand that for proper operation, the device driving the data I/Os of the TXB0106 must have drive strength of at least ±2 mA.

I wanted to know if TXB0106 will be able to drive FPGA IOs when above condition is met?

Thanks and Regards

Sushruta

Hello Sushruta,

I do not know the input characteristics of yoru Xilinx FPGA, but I will assume this interface you're referring to a unidirectional push-pull setup, similar to SPI or UART. In this case ,the TXB0106 should be able to drive the IOs of the FPGA so long as your traces are short. I also do not know which frequency you're wishing to operate at. So I am assuming you are operating within the devices specifications.

In order to have the driver of another device let the TXB0106 know that it is transmitting, it must be able to drive at least +/-2mA. Once the TXB0106 realizes that a device is driving a signal, it will transmit this signal to the other side of the device.

Thanks for the information provided.

Does this mean, if the current of the input signal is more than 2mA (which is guaranteed in our case), the device will simply pass the input signal to output port?

 

That is correct. If your driver which is transmitting the signal is more than 2mA, then you will be able to over come the TXB's input driver easily, and the device will pass the input signal to the output port.

Thanks,
Jonathan