ESP12 12v converter

Projects General Guidance
1

Hi Everyone,

I'm looking for a way to convert DC 12v to 3.3v for a new ESP project. All components will be added to a PCB.
The module will be placed in my car, so the input voltage will be 12v.

I don't have much knowledge about power requirements for electronics, so I did some reading.
At first I looked into the AMS1117 which is quite frequently being used with ESPs, but some people pointed out that it's not a good choice when the input voltage is much higher than the output voltage. It would waste a lot of power and create a lot of heat.

A Buck converter would be much better it seems, so I looked around and found two candidates.
One of them is the [AP1509-33](https://nl.mouser.com/datasheet/2/115/diodes inc._ap1509-1163839.pdf) which is very small and SMD. I like that a lot, but it does require an additional heat sink and capacitors.
As I want to keep the PCB as simple as possible the other option might be better. It's the TSR 1-2433.

Can anyone recommend either of these two, or maybe some other DC converter?
Also would I need additional capacitors on the input and output side of the converter?

Cheers!
Luck7

2

I use this DC 12v 24v to 5v Step Down Converter Regulator 5A 25W Power Adapter Reducer for Car Electronics Truck Vehicle Boat Solar System (Accept DC 8-40V Inputs) to run my RPi in my car and I run 2 ESP32's and other electronics on my weather station.

I use, on the weather station a MCP1700 to bring the 5V down to 3.3V, which is used for the ESP32's power.

Works great last a long time.

3

Thanks Idahowalker, appreciate the answer!

I'm looking for something that can be put on a PCB though. Maybe I should have added that in my post. I'll edit it.

4

In all my bare ESP-12 module projects (usually 24volt in) I use the D24V5F3 from Pololu.
With an additional 470uF/6.3volt tantalum cap on the 3.3volt rail, to bridge the ~400mA transmit current spikes.

Chips like the MPM3610, used on the Nano Every etc., could be interesting if you want a bare smd part.
Leo..

5

I have decided to go with the AP1509-33
It requires some extra components on the PCB. I think below setup should work.

1039×330 3.46 KB

  • The Diode on the left is not required. This line is 12v.
  • The TP2 on the far right is a pad to test the connection. Also not required.
  • C1 and C2 are 470uF

Sources I used:
https://nl.mouser.com/datasheet/2/115/diodes%20inc._ap1509-1163839.pdf
https://www.diodes.com/assets/Part-Support-Files/AP1509/AP1509-EVM.pdf

I'll post the results when I receive the PCB.

6

After some testing the AP1509 seems to work perfectly.
It takes some space on the PCB but works well and doesn't get hot, even without a heat sink.
Can recommend it for anyone who needs to convert 12v to 3.3v.

7

This switching converter at Digikey also works well.
https://www.digikey.com/en/products/detail/murata-power-solutions-inc/OKI-78SR-3-3-1-5-W36-C/2259780

8

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