Vehicle power supply

I’m currently working on a project that plugs LED strips into a car. I have all of the control circuitry figured out (I think) but the power supply is giving me trouble.

I need three voltage levels: 12v @ ~4A max to drive the LEDs (WS2811s, 1.2A/m, roughly 3 meters), 5v @ ~1A for some additional LEDs and a few ICs and 3.3v @~1A for the microcontroller and accessories.

I’m planning on powering this out of the cig socket: Usually fused at 10A, but the voltage is anywhere from 10-15 volts.

So, I’m thinking I need a boost/buck that can output 12V at 6A to smooth the incoming power and then some 12v-5v/3.3v regulators for the rest. Haven’t decided on switch mode or linear yet.

Is there any suggestions for a good boost/buck converter for this application? Looking around, most of the parts are only on “Evaluation Boards” like TPS55288 (which, I think is overkill but it would handle my requirements).

Any help is appreciated.

Haven't decided on switch mode or linear yet.

That bit is easy, don't even think about linear, all they do is waste power as heat. In an case, the can only lower the voltage, they can't produce 12V from 10V

No specific recommendations, but your favourite retail web site is full of them.

johnnywycliffe:
I'm currently working on a project that plugs LED strips into a car. I have all of the control circuitry figured out (I think) but the power supply is giving me trouble.

I need three voltage levels: 12v @ ~4A max to drive the LEDs (WS2811s, 1.2A/m, roughly 3 meters), 5v @ ~1A for some additional LEDs and a few ICs and 3.3v @~1A for the microcontroller and accessories.

I'm planning on powering this out of the cig socket: Usually fused at 10A, but the voltage is anywhere from 10-15 volts.

So, I'm thinking I need a boost/buck that can output 12V at 6A to smooth the incoming power and then some 12v-5v/3.3v regulators for the rest. Haven't decided on switch mode or linear yet.

Is there any suggestions for a good boost/buck converter for this application? Looking around, most of the parts are only on "Evaluation Boards" like TPS55288 (which, I think is overkill but it would handle my requirements).

Any help is appreciated.

The buck/boost requirement is problematic - I'd consider a boost converter to 18 or 24V, followed by
buck converters for all the voltages you need - easier to find units that way I think. The cheap LM2596
modules are good for a couple of amps of buck conversion and are adjustable. The step-up converter
would need to be 50W rated - that's going to be the costly item.

If you can live with a low-drop-out linear regulator for the 12V that might be another approach (though
the high current rating will reduce the options I think).

MarkT:
The buck/boost requirement is problematic - I'd consider a boost converter to 18 or 24V, followed by
buck converters for all the voltages you need - easier to find units that way I think. The cheap LM2596
modules are good for a couple of amps of buck conversion and are adjustable. The step-up converter
would need to be 50W rated - that's going to be the costly item.

If you can live with a low-drop-out linear regulator for the 12V that might be another approach (though
the high current rating will reduce the options I think).

After must googling based on the separate boost-buck idea, I came up with this:
2 x TPS65235-1
2 x LM1085-12 Low drop out or MP8854GL-Z if I go with a switching buck.

Since there's 4-6 LED strips attached, I can break them into groups of three, and they'll still be within parameters. I can break the other two voltage levels off without needing the boost circuitry since I can easily get 11-14V to 5V power regulators.

Thank you for your help.