LSF0204: Asking for the LSF0204RUTR design question

SHH

Part Number: LSF0204

Hi team,

Please help confirm LSF0204RUTR Bidirectional Multi-Voltage Level Translator, We use on UART interface but RX/TX signal have not connect pull-up resistor.

customer want to ask if it affects the output level of the signal

BR,

SHH

over 6 years ago

0 Clemens Ladisch over 6 years ago

Guru 326180 points

An A-side output will be clamped to VCCA, but the rising edge will be very slow.
A B-side output will float when the A-side input is high.

You should have pull-up resistors on all LSF outputs.

(See Voltage-Level Translation With the LSF Family.)

0 Karan Kotadia over 6 years ago in reply to Clemens Ladisch

TI__Genius 16735 points

Hi,

I agree with Clemens's response.

https://training.ti.com/translation-lsf-family-0?context=1134826-1139264-1134794

I also recommend watching the following series on LSF translation. It will help you understand why the output on B side will start to float when A side is high.

Thanks!

-Karan

Logic

Logic forum

LSF0204: Asking for the LSF0204RUTR design question