Micro-controllers DC/DC Step-down 6-42V to 12V/5V

In my pursuit of a suitable power solution for my ESP32, which required an input voltage of 42V, I undertook the task of conceptualizing and designing a compact PCB. The primary objective was to create a reliable device capable of efficiently transforming the high voltage input to a stable output voltage of 12V or 5V, thereby ensuring optimal performance and compatibility with the ESP32 microcontroller. This endeavor stemmed from the imperative need for a reliable and tailored power supply solution to meet the specific requirements of my project.

List of components used:

• BD9G101G_EVK (DC/DC Converter)
• D1 Schottky Barrier Diodes
• L1 6.8uH
• R10 680R
• R11 3.9K
• C1 100nF/0402/16V
• C2 4.7u/0805/50V
• C3 10uF/0603/10V
• C4 15nF/0402/50V

In the image above, you can see the schematic used to create the PCB. Additionally, I have also provided the detailed list of the components used BOM with the JLCPCB codes to buy them.

For those who would like to support my work can purchase the board directly at the following links:

https://thesavbaz.etsy.com/listing/1554505978

https://www.tindie.com/products/saveriop/microcontroller-dcdc-stepdown-upto-42v-to-12v5v/

The image above explains exactly how the converter works. The operation of the output voltage regulation is essentially based on the choice of two resistors and a capacitor.

For example, based on the component datasheet, ROHM Semicon suggests:

For an output of 5V/500mA: R1=3.9kΩ R2=0.68kΩ and a of Csp = 0.1uF or 0.22uF

For an output of 12V/500mA: R1=7.5kΩ R2=0.51kΩ Csp = 0.1uF

Obviously, based on your needs, it is possible to calculate the appropriate resistances and CSP capacity to have the desired output voltage, based on the following formulas:

Vout = ((R1+R2)/R2)x0.75[V]

Csp = (4.7K/R1)x0.15

The outcome of the extensive design efforts manifests as an exceptionally compact printed circuit board (PCB) measuring a mere 17x9mm. Remarkably, this achievement has been realized with minimal components, yielding a product of utmost reliability. I extend my sincere gratitude to JLCPCB, whose invaluable support and collaboration not only facilitated the testing of the designed board but also enabled its successful realization.

JLCPCB stands as a prominent and esteemed Asian enterprise renowned for its unparalleled proficiency in the production of top-tier PCBs. This company has consistently demonstrated an unwavering commitment to delivering PCBs of superior quality while maintaining cost-effectiveness, solidifying its position as a leader in the industry.