Part Number: TPS54540
24V DC to 5V DC just do with reference design in datasheet , the output is ok ,but the wave form in SW pin as attached exceed the range in datasheet ：SW –0.6 45V，the max in the waveform is -2.3V.
So if this is abnormal? if it will lead to a failure in long time? Thanks ~
Saber, Absolute max voltage on SW is 45V. Your ringing appears to go over 40V (not sure exactly how high). This should probably be addressed or the part may fail or have a shortened lifetime. -2.3V is also very low. The low-side FET should clamp this to about -0.6V. Please share your layout. Ringing is often caused by a large loop in the switch-node transient current. Other methods of reducing ringing (once the layout is optimized) is an RC snubber (RC in series connected from SW to GND), a boot resistor (~3-10 ohms in series with Cboot), or gate resistors (resistors in series with the gates of the FETs). These are all at the expense of efficiency so it's best to get as good as you can with layout alone. -Sam
We are glad that we were able to resolve this issue, and will now proceed to close this thread.
If you have further questions related to this thread, you may click "Ask a related question" below. The newly created question will be automatically linked to this question.
All content and materials on this site are provided "as is". TI and its respective suppliers and providers of content make no representations about the suitability of these materials for any purpose and disclaim all warranties and conditions with regard to these materials, including but not limited to all implied warranties and conditions of merchantability, fitness for a particular purpose, title and non-infringement of any third party intellectual property right. TI and its respective suppliers and providers of content make no representations about the suitability of these materials for any purpose and disclaim all warranties and conditions with respect to these materials. No license, either express or implied, by estoppel or otherwise, is granted by TI. Use of the information on this site may require a license from a third party, or a license from TI.
TI is a global semiconductor design and manufacturing company. Innovate with 100,000+ analog ICs andembedded processors, along with software, tools and the industry’s largest sales/support staff.