Powering the Raspberry Pi 3 With MP1584 Voltage Step-Down Converter

The Raspberry Pi 3 is a very impressive piece of hardware for the price, but it has its flaws. One challenge is supplying power to a Pi 3. Like all the Pi boards, power is supplied via a standard micro USB plug. This implies the Pi only needs USB level power with its specified maximum of 0.5 amp @ 5 volts = 2.5 watts. In reality, this USB port is abused beyond the specified range. The Raspberry Pi foundation recommends the power supply for a Pi 3 should supply up to 2.5 amp @ 5 volt = 12.5 watts. Five times the USB specification maximum.

None of the USB power sources I already had could handle this workload. I originally had ideas about running a Pi 3 off of a portable USB charger, but that failed under the vastly greater power draw. I went looking online for solutions.

I needed an efficient DC to DC voltage regulator that can handle the maximum power draw of a Raspberry Pi 3 without consuming a lot of power itself. Since the voltage of a battery changes as it drains, the converter needs to handle a range of input voltages while holding the output voltage steady.

The MP1584 chip from Monolithic Power Systems fit the bill, but I didn’t want to deal with a tiny surface mount IC, nor do I have the skill to design the supporting circuit required. Consulting with a few electronics hardware hobbyists, I got the recommendation to take the reference design out of the datasheet and build that.

And then, an even better recommendation: If it’s a popular chip, and its reference design is good enough, somebody would have mass-produced it and put it on Amazon. And indeed, they have. A lot of vendors, in fact, from all around the world.

I scrolled through a few of the listings but didn’t really have a good feel on how to judge one vendor against another. So I took the easy way out: I clicked on the “Amazon’s Choice” link to this offering.

Once the module arrived, I soldered battery connectors to the input and a micro USB plug to the output. I adjusted the output voltage to 5 volts, and connected everything to power up my Raspberry Pi 3.

PiVoltage

So far it has worked very well. The Raspberry Pi 3 stayed running through tasks that demanded extra power, that would previously trigger a low-power brownout with my existing USB power sources. The output voltage held steady as the battery drained.

Functional, inexpensive, and I didn’t even have to deal with surface mount components! This was a win.

 

2 thoughts on “Powering the Raspberry Pi 3 With MP1584 Voltage Step-Down Converter

  1. Hello,
    I was about to do the same thing (power up the RPI with MP1584 board) than I decided to google for it and found your post.
    One thing that worries me is that the MP1584 board, if subjected to electrical noise, outputs wildly noisy power. If you touch it, for example the inductor on the board, the output will fluctuate. Also, if the module gets faulty, it causes a situation there Vout = Vin.
    So did you run this setup for a long enough time without any problems?
    Best Regards,
    Can

    Like

    1. I can say it has worked well so far for my hobbyist level projects that usually run for a few minutes to hours. I haven’t observed any of the behavior your described, but I agree they would definitely be valid concerns for an actual engineered product that is intended to run for years.

      Like

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