TLV1704-SEP: Evaluating Comparator Suitability for 3.3V to -7V Logic Level Translation

Dhir Gandhi

Part Number: TLV1704-SEP

Tool/software:

I want to use this comparator for an application where I need to translate 3.3V logic to -7V. I plan to supply this comparator with -7V to Vs- and 0V to Vs+. Is this IC suitable for such an application?

1 month ago

+1 Ron Michallick 1 month ago

TI__Guru**** 165236 points

Hello Dhir,

Supply +3.3V and -7V power to comparator. Output VOL will be -7V and VOH will depend on pull up resistor. Pull up to 0V for this application.

0 Dhir Gandhi 1 month ago in reply to Ron Michallick

Prodigy 190 points

Hi Ron,
Thanks for your help.

Would it be an issue if I apply 0V to Vs+?

I'm a bit unsure about using this IC, as the datasheet doesn't mention whether it's bipolar or not.

Below is the circuit I am planning to implement:

0 Ron Michallick 1 month ago in reply to Dhir Gandhi

TI__Guru**** 165236 points

Gandhi,

Your inputs are now outside the VCM range. So that is bad.

Dhir Gandhi said:
bipolar or not

TLV1704-SEP only has two supply pins. Therefore it doesn't care and can't know if these two pins are bipolar or not.

Only devices with 3 or more supply pins can know or care.

+1 Paul Grohe 1 month ago in reply to Dhir Gandhi

TI__Guru 60786 points

Hi Gandhi,

Place +3.3V on V+ to accept positive voltages and you should be good. Output will still swing between 0V and -7V.

The TLV1701-SEP is on a BiCMOS process, but is mostly bipolar (BJT) with a few MOSFET current sources.

This is covered in the TID and SEE radiation reports available in the "Technical Documentation" section of the TLV1701-SEP product folder. It has passed SEL.

https://www.ti.com/product/TLV1704-SEP#tech-docs

0 Dhir Gandhi 1 month ago in reply to Ron Michallick

Prodigy 190 points

Thanks Ron!

0 Dhir Gandhi 1 month ago in reply to Paul Grohe

Prodigy 190 points

Thanks Paul for clarifying.

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TLV1704-SEP: Evaluating Comparator Suitability for 3.3V to -7V Logic Level Translation