LSF0102: VrefB on the LSF0102DQER.

Sky Kao

Part Number: LSF0102

Tool/software:

I would like to ask about the usage of VrefB on the LSF0102DQER.

From the datasheet, VrefB and EN are connected together first and then pulled up through a 200K resistor.

In my current design, only EN is pulled up to 3.3V through a 200K resistor, while VrefB is directly shorted to 3.3V. Is this design acceptable?

6 months ago

0 Clemens Ladisch 6 months ago

Guru 316690 points

This will not work; the output voltage on A1/A2 will be about 2.7 V.

The EN voltage must not be much larger than Vref_A; the biasing circuit ensures this. Connecting EN directly to the lower supply voltage would also work.

See [FAQ] How do the LSF translators work?

0 Tyler Townsend 6 months ago

TI__Mastermind 47328 points

Hi Sky,

The engineer who supports these devices is currently ooo. Allow us to get back to you Tuesday of next week.

Regards,

Tyler

0 Jack Guan 6 months ago

TI__Mastermind 40136 points

Hi Sky,

I agree with Clemens' answer here, you may also see the LSF Logic Minute Videos for additional clarification. Phttps://www.ti.com/video/series/understanding-the-lsf-family-of-bidirectional--multi-voltage-lev.html

lease let us know if you have any additional questions.

Regards,

Jack

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LSF0102: VrefB on the LSF0102DQER.