LSF0204: Pull-Ups Needed

Kyle Mehringer

Part Number: LSF0204
Other Parts Discussed in Thread: LSF0102,

Hello,

The LSF0204 has a requirement that VrefB > VrefA+0.8V, correct? LSF0102 has a similar requirement for normal operation and advices that for instances where VrefB < VrefA+0.8V, pull-ups are recommended on the input side. Does the same apply to LSF0204?

Thank you,

Kyle

over 3 years ago

0 Clemens Ladisch over 3 years ago

Guru 316510 points

Those pull-ups are recommended on the output side for down-translation.

VrefB is not required to be the same as the I/O voltage; you can use any higher voltage that happens to be available on your board.

0 Jack Guan over 3 years ago in reply to Clemens Ladisch

TI__Mastermind 39986 points

Hello Kyle,

To further add on to Clemens response, it is not ideal to have the device operate in conditions where VrefB < VrefA +0.8V. Pull ups are also recommended on the input if you are up-translating.

Here is more information regarding device operation, specifically videos 7 in regards to your question.

Regards,

Jack

0 Kyle Mehringer over 3 years ago in reply to Jack Guan

TI__Intellectual 1510 points

Hello Clemens and Jack,

Thank you for the response. I'm just confirming the pull ups will be needed in up translating from 1.2V to 1.8V. I wasn't able to find this information in the datasheet.

Thank you,

Kyle

0 Jack Guan over 3 years ago in reply to Kyle Mehringer

TI__Mastermind 39986 points

Kyle,

More information can be found in the Up Translation of the Logic Minute videos. Pull ups will be needed if device output is open drain, or if input leakage current is greater than 1uA.

Regards,

Jack

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LSF0204: Pull-Ups Needed