Using a CBT Device as a 5V-to-3.3V Level Shifter or Voltage Translator

Mike Combs

Other Parts Discussed in Thread: SN74CB3T3245, PCA9306

The CBT logic family can interface a 5V part of a system with a 3.3V part of a system by adding a diode between the external Vcc and the output-enable terminals.

Please reference application report "Flexible Voltage-Level Translation with CBT Family Devices": http://www.ti.com/lit/scda006 .

over 16 years ago

0 Aleksander Vershinin over 16 years ago

Prodigy 140 points

Is it possible to convert 3.3 V CMOS to 5V CMOS using SN74CB3T3245 and pull up resistors?

0 Chris Cockrill over 16 years ago in reply to Aleksander Vershinin

TI__Mastermind 46480 points

Hi Aleksander

Yes this will work. see appnote page 28. http://focus.ti.com/lit/an/scda008/scda008.pdf

0 Eli Blank over 15 years ago in reply to Chris Cockrill

Prodigy 10 points

Can I connect I2C I/F (with pull-ups to 5V) to the SN74CB3T3245?

Thanks

0 Aleksander Vershinin over 14 years ago in reply to Eli Blank

Prodigy 140 points

You can use SN74CB3T3245 only for 5V-3.3V, 5V,3.3V-2.5V translation. I prefer to use PCA9306 for I2C- it is more flexible.

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Using a CBT Device as a 5V-to-3.3V Level Shifter or Voltage Translator