Important: I will update this page when the improved version is ready.
For now, I will wrap up my Illumina Blast Module post and the intended application of them IRL.

Introduction

This is a buck converter based on the AP64352 IC by diodes incorporated to replace the lm2596 delivering more efficiency and protections.

This is a prototype version to test the concept.

Project function

High reliability step down regulator for moderate power IoT devices.
VRM for IoT devices and projects.
lm2596 Replacement Version 1

Project Parameters

LCSC/C2071665 (AP64352SP-13) Datasheet

Designed according to the datasheet.

The AP64352 is a 3.5A, synchronous buck converter with a wide input voltage range of 3.8V to 40V.

The device fully integrates a 75mΩ high side power MOSFET and a 45mΩ low-side power MOSFET to provide high-efficiency step-down DC-DC conversion. The AP64352 design is optimized for Electromagnetic Interference (EMI) reduction and Frequency Spread Spectrum (FSS) with a switching frequency jitter of ±6%, which reduces EMI by not allowing emitted energy to stay in any one frequency for a significant period of time.

Hardware Design

This circuit comes with over current protection, TVS (transient voltage) protection and reverse polarity protection because "I keep destroying lm2596 modules from reverse polarity and inductive loads."

I also included a low pass PI filter to remove input noise with common values.

Plenty of output of capaictors are used to account for the load which may draw current spikes occasionally. As the indicator light is usually ignored or not seen, a 47K resistor is used to keep it dim.

Voltage is adjusted at R5(+R6)

R5 = R4 * ((VOUT/0.8V) - 1)

For example, 5v is required then R5 = R4 * ((VOUT/0.8V) - 1) ➡ 22100 * ((5/0.8) - 1) ➡ 116025 Ohms, which reduces to 115.8K as it is a resistor that can be purchased.

More info on page 14/21 on the datasheet LCSC/C2071665 (AP64352SP-13) Datasheet

Self Information

Socials

https://www.reddit.com/user/4b686f61/
u/4b686f61
https://www.youtube.com/@4bSix86f61 I will begin uploading asap
YouTube butchered my randomly generated username.

Things to help keep yiur sanity while designing

Music that isn't mainstream

Self

The buck regulators sold on AliExpress lack mounting holes and voltage selection. Also, SOT-23-5 package regulation ICs suffer from poor heat dissipation, They are good for powering an ESP32 though. Start from SOP-8 or flip chip packages for buck converters.
Since this is an old revision, the statement above may be contradicting as there is no potentiometer.

Revisions

With the help of u/F84-5/, I will redesign the converter circuit to have preset values of 3.3, 5, 9 and 12 volts instead of a 3296 trimmer "potentiometer". Although the 3.3v is more like 3.1v due to resistor limitations, You would power an ESP32 with an LDO and 5v source to remove noise and provide a stable voltage. 3.3, 9 and 12 volts are nice to have voltages.

24V PSU -> Protections (fuse/TVS) -> Buck Converter 5v -> 3.3v LDO -> ESP32

I will also cut down the footprint of the circuit while not using "low quality of life" screw terminals. There will be design optimizations to keep it compact, efficient and cut down on BOM. 0805 components are switched out for 0603 and the silkscreen may be omitted so it doesn't trigger my OCD which makes components get placed further apart.

Reddit Post

Reproduction is not prohibited without the author's authorization.

Attatched below is the font. This font was used as it's easy to read on the silkscreen.

https://fonts.google.com/specimen/Jua

Note: Any words wrapped in "quotations" were replaced because the moderation rejected the english slang or term.