Adjustable Low EMI Switching Power Supply

[Hesambook]

A power supply is an essential tool on every electronics bench. The TPS54202 is a highly efficient 2A synchronous buck converter with a wide 28V input voltage range and low EMI figures, making it suitable for various applications. These features make the TPS54202 an excellent choice for building a power supply.

To achieve a low noise level and ensure high performance, I implemented a variety of input and output filters, along with following several PCB design techniques. The chip operates at a switching frequency of 500KHz and is equipped with internal loop compensation. Setting up the power supply is simple—just connect the input to a step-down AC transformer (e.g., 220V to 15V) and use a multiturn potentiometer to adjust the output voltage to your desired level.

For the schematic and PCB design, I utilized Altium Designer 23 and shared the project with my friends for feedback and updates using Altium-365. The fast component search engine, Octopart, proved invaluable in quickly obtaining component information and generating the Bill of Materials (BOM). To ensure high-quality fabricated boards, I sent the Gerber files to PCBWay.

I tested the circuit for output noise and load step response using Siglent SDS2102X Plus oscilloscope and Siglent SDL1020X-E DC load. I am confident that this circuit will meet your requirements for a compact and efficient power supply, providing reliable performance on your electronics bench.

References

Schematic + PCB + Gerber: https://bit.ly/3WLFtRZ

[1]: TPS54202: https://octopart.com/tps54202ddct-texas+instruments-71538129?r=sp

[2]: 470uF-35V: https://octopart.com/eee-fk1v471aq-panasonic-44406255?r=sp

[3]: 22uH-3A: https://octopart.com/etqp5m220yfm-panasonic-24904108?r=sp

[4]: 5K Potentiometer: https://octopart.com/ss34a-multicomp-18903924?r=sp

[5]: SS34: https://octopart.com/ss34a-multicomp-18903924?r=sp

 

[D.A.(Tony)Stewart]

Looks nice BUT what were your Design specs for EMI, noise, load regulation, step response, overshoot and your DVT results? Make a list. Otherwise they are just pretty pictures. Judging by the quality of video and layout , I expect high quality results.

But to teach others, it is most important to have detailed design specs and a test plan with a table of results with conditions. Then a summary of things that improved from previous design and for next iteration (if). Also what was the reference for your design? octopart? I doubt.

--- Updated Jun 1, 2023 ---

Octopart has good prices Digipart has even better prices and worse. Of course you need volume to reduce delivery costs.

e.g. 0.25 https://www.digipart.com/part/TPS54202DDCT

 

[Hesambook]

Octopart has good prices Digipart has even better prices and worse. Of course you need volume to reduce delivery costs.

octopart is not a sales website, just provides information. I think its business model is through ads.
please watch the content, I hope you get your answers. it is not a deep test like a test department, but it gives an insight into this design

 

[D.A.(Tony)Stewart]

octopart is not a sales website, just provides information. I think its business model is through ads.
please watch the content, I hope you get your answers. it is not a deep test like a test department, but it gives an insight into this design

Both sites are info only, not distributors.