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TXB0102: Level Translator with input of both 5V TTL and 5V CMOS and output of 3.3V CMOS

Rajesh Kaliyaperumal
Intellectual 930 points
Part Number: TXB0102
Other Parts Discussed in Thread: SN74LVC2G07

Hi ,

I am looking for a level translator with the following requirements:

Inputs :5V TTL and 5V CMOS

Output: 3.3V CMOS

Bidirectional type

2 Channels per port

 

It would be great if i can get a two devices with Pin to Pin compatible (for easily replacing the IC if i use 5V TTL  peripheral or  5V CMOS  peripheral)

Is it possible to get an device like this ?

Looking for your reply at the earliest

Regards,

Rajesh

  • 0
    TI__Guru* 96862 points
    Hi Rajesh,
    When you say "bidirectional type" do you mean that you want to be able to change the direction of each channel (5V to 3.3V or 3.3V to 5V) or you need a device that automatically changes direction? I'm confused because you list the inputs as always being 5V TTL/CMOS and the output as always 3.3V CMOS.

    Can you tell me about what you are designing? Will it have just random things attaching to it? Or is it part of a system that utilizes 5V TTL/CMOS?
  • 0 in reply to Emrys Maier
    Intellectual 930 points

    Hi Emrys,

    I m gonna use a sensor which is available in 5V CMOS level and 5V TTL, but my microcontroller I/O logic level is 3.3 V CMOS.

    There are two signals which need to be level shifted :

    1) one is input to sensor from micro controller  and

    2) other one is output from sensor to micro controller.

    I have already selected TXB0102DCUT part which will support 5V CMOS level sensor but it will not be suitable for 5V TTL.

    Hence I am looking for level shifter which is pin to pin compatible for 5V CMOS and 5V TTL such that I could replace the IC in PCB whenever I use 5V CMOS or 5V TTL sensor.

    What I meant to say using " Bidirectional " is that automatic direction change since two signals are in different directions (that would be better to have if it is available or else I have to use separate level shifter for each signal ) 

    Regards,

    Rajesh 

  • 0 in reply to Rajesh Kaliyaperumal
    TI__Guru* 96862 points
    There are compromises with using auto-bidirectional translators. In this case, since the direction isn't changing, I would recommend using unidirectional translation.

    The SN74LVC2G07 can be powered from 3.3V and can meet both requirements -- the supply sets the input thresholds, and the output voltage is set by a pull-up resistor. The inputs are over-voltage tolerant, so 5V is allowed and won't cause any problems.
  • 0 in reply to Emrys Maier
    Intellectual 930 points

    Hi Emrys,

    Thanks for your suggestion.

    I will use this part since open drain output will support both voltage level.

    Since the input 5V tolerant, I am planing to use 3.3 volts as supply voltage for this part.

    And I will be using 3.3 volts as pull up voltage for one signal and 5 volts as pull up voltage for another signal.

    Regards,

    Rajesh K