LSF0204: Schematic and Layout Verification

Hi Teja,

The pull-down resistors will cause problems for the LSF0204, so I would recommend removing R5-8, and R13-16 entirely.

As for the layout, I would recommend a few things.

(1) Be sure to provide a solid ground connection to the bypass capacitors. You want those connections to be as short as possible, so I would run a via for each, rather than having the long line between them.

(2) Kinks in traces will cause impedance changes and reductions in signal integrity. Try to keep those traces straight when you can.

(3) The trace just barely hits the edge of the HI04 pin. I would recommend running it straight into the pin on one side, then straight out on the other side.

There's a _lot_ of information out there on how to design a PCB. There are a lot of rules to follow, and I've never run into a group of engineers that does PCB layout exactly the same every time.

For some pointers on high speed signal layout, this application report might help: High-Speed Layout Guidelines

Hi Teja,
There's no magic solution to voltage translation in any situation -- you need to know the parameters of your circuit and design to meet those requirements. The circuit you have shown me will do translation in many applications, but it has limitations.

I cannot design a circuit for you, but I can answer questions regarding a specific device or situation. You must consider how load and transmission line effects will hurt your system's signal integrity, and decide if the translator you choose will meet your system's needs.

Have you watched the Logic Minute series on the LSF translators? It's extremely informative on how passive switch translators operate: training.ti.com/LogicMinute

There are also many application reports and documents on our website that you can use to learn more about voltage translation. You can start here: www.ti.com/.../overview.html

Good luck with your project!