LM3414HV: Schematic review

Hello Kai,

Everything looks okay except when your input voltage is on the high range, 50V.  The minimum on-time:

"7.3.2 Minimum Switch ON-time
As the LM3414 features a 400 ns minimum ON time, it is essential to make sure the ON time of the internal
switch is not shorter than 400 ns when setting the LED driving current. If the switching ON time is shorter than
400 ns, the accuracy of the LED current may not maintain and exceed the rated current of the LEDs. The ratio of
the LED forward voltage to input voltage is restricted by the following restriction, as shown in Equation 1."

At 500 KHz minimum on-time will be around 300 ns with 6V output and 50V input.

Also, TVS1, SMAJ70CA, will not protect the LM3414, the clamping voltage is much too high.  The '70' is the standoff voltage, not clamping voltage.

Best Regards,

Hello Kai,

I haven’t heard back from you, I’m assuming you were able to resolve your issue.
If not, just post a reply below (or create a new thread if the thread has locked due to time-out)

Best Regards,

Hello,

It's not real clear in the picture if that is a ground plane on the bottom and what it covers.  I would added some vias next to the (-) side of CIN to make the GND path shorter, CIN is the source for the high frequency switching current.  Other than that is should work beside the points I made about Vin, Vout and switching frequency plus TVS1 above.

Best Regards,