• Resolved

LMR14050-Q1 high ringing voltage at rising and falling edge



Customer of mine intend to use LMR14050-Q1 (LMR14050SSQDDARQ1) in their car audio system however they’re seeing voltage overshoot and undershoot at rising and falling edge causing some interference with the radio frequencies

I’ve attached the material for your reference.


My questions are as below:

- the Rt value in customer schematic is 84K, thus calculated switching frequency is 308KHz. Would this cause the AM interference?

- Also, the value output capacitor is rather huge (3400uF). Would this cause the voltage overshoot/undershoot?

- Is there any way to reduce the ringing voltage effectively?

- could you help to review and comment the schematic and layout?

LMR14050-Q1 Interference issue.pdf