CD4504B for 3.3V to 15V level translation

Chris Donovan

Prodigy 80 points

Other Parts Discussed in Thread: CD4504B, TMS320F28335

I'm planning on using the CD4504B part to level translate from 3.3V to 15V.

The inputs to the CD4504B come from a '28335 DSP (3.3V).

Vcc for the CD4504B will be 5V. Vdd for the CD4504B will be 15V. CD4504B will be in TTL-CMOS mode.

The specs on the '28335 outputs and the CD4504B inputs look like there should be no issue.

Two questions:

1. Is there a better part available to accomplish 3.3V to 15V level translation?

2. Is there an issue or limitation with the CD4504B in this application that I am not aware of?

Thanks,

Chris

over 10 years ago

0 ShreyasRao over 10 years ago

TI__Guru 62080 points

Hi Chris ,

CD4K family is the only family rated for higher voltages beyond 7V I know of .you might need multi level translation since 3.3V to 15V is not possible in single step.

http://www.ti.com/product/CD4504B/technicaldocuments .Good documents to read which can help in your design.

0 Chris Donovan over 10 years ago in reply to ShreyasRao

Prodigy 80 points

I don't think I need multi level translation. The outputs of the 28335 are within the range of the CD4504B inputs (see specs copied below). I'm powering Vcc with 5V. Am I missing something here?

TMS320F28335 outputs
high output: 2.4V to 3.3V
low output: 0V to 0.4V

CD4504B inputs (TTL-CMOS, Vcc=5V and Vdd=15V)
high input: 2V to 5V
low input: 0V to 0.8V

Thanks,
Chris

0 ShreyasRao over 10 years ago in reply to Chris Donovan

TI__Guru 62080 points

Hi Chris ,

I would like to add though that the Vih and Vil levels are w.r.t inputs while the outputs switching level may not necessarily correlate to this but, given the specs I feel that the multi level translation isn't required since you have a good margin .

Logic

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CD4504B for 3.3V to 15V level translation