This thread has been locked.
If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.
I've designed a power supply unit on LM2576-adj. There are 27V DC on the input and on the output I've set 20V. There are 3 LM2576's connected parallel after greatz bridge together with 3 electrolitic capacitors 4700u. On the output there is coil 220uH, 3A shottky diode and 1000u electrolitic capacitor. On the PCB there is 3 IC mounted to the heat sink.
The problem which I receive is that when I connect load with more than 1A current, one of the IC's which is in the middle gave me a noise on the otuput approx 60mVp-p and about 3kHz freq (similar to saw shape). I can hear this in speakers in my audio system. On the rest two IC's I doesn't hear anything. Could you advice what can cause this. I've already exchange all the parts and it doesn't help.
The PCB board is already updated according to schematic diagram (the wire layout is old). Below is the diagram and pcb board.
In reply to Prashanth Suvarna:
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.