PNMini2A is part of a kickstarter campaign: https://www.kickstarter.com/projects/pnmini/pnmini-positive-negative-power-supply-module-for-m

The default output voltage is configured to 3.3V, while t is configurable through 3 programming resistors.

Please note that the video cover page shows prototype 1. What you will get is the final version, as shown on the pictures.

For details, please refer to the full datasheet:

*Full datasheet link: *

https://drive.google.com/file/d/0B0aPceJUD-kdNFlKcldxS0lBUDA/edit?usp=sharing

PNMini is a family of high performance, easy-to-use DC/DC Power Modules for DIY electronics.

PNMini can be used as positive supply or negative supply. If both positive and negative supply rail are needed, just connect two PNMini modules together. No hardware changes are required.

PNMini is available in a small PCB package that enhances thermal performance and allows for hand soldering or plugin use. It provides +3.3V/-3.3V, +5V/-5V, or +12V/-12V output directly to your circuits requiring no external components.

Application Examples

PNMini can be used in all kinds of DIY electronics projects. Below are two application examples:

• Arduino drone with longer battery life

PNMini can be used to power your Arduino drone. A miniature Arduino board is usually powered by 3.3V. The motors and sensors are usually 5V. You can use 3 li-ion battery stack and two PNMini to get the voltage you want! It's more efficient than LDO. PNMini provides up to 92% efficiency while LDOs can hardly achieve more than 50% efficiency. That's a 40% longer battery life for your design!

• A simple ECG amplifier

Another application example is a simple ECG amplifier which can display your ECG waveform on a oscilloscope. For sensor or amplifier applications, dual supply is often preferred. Positive supplies are everywhere, but sometimes it's difficult to find a negative power supply. PNMini solves the problem by generating both positive and negative supply from a single source.

How does it work?

PNMini combines positive and negative supply capability into one module. The positive supply is a buck converter; the negative supply is a inverting buck-boost converter. Some buck converter controller ICs can be used as inverting buck-boost converter controllers. A Texas Instruments application note (http://www.ti.com/lit/an/slva257a/slva257a.pdf) has one such application.

The figure below shows that if you switch the diode and the inductor in a buck converter, it becomes a buck-boost converter. And this is how PNMini works.

What about the technical details?

What about the technical details?

More key features of PNMini-2A module are:

• High efficiency at light loads: 85% efficiency at Vin=7V
• Typical 5uA shutdown quiescent current
• Slow start limits inrush currents
• Under voltage lock out (UVLO) protection
• Over voltage transient protection
• Thermal shutdown protection
• Cycle-by-cycle current limit enables short circuit protection

How efficient is it? Shown below are some test data:

How does the efficiency compare with 7805/7905? PNMini is a DC/DC switching regulator, which can easily achieve more than 90% efficiency; 7805/7905 are linear regulators, the efficiency is usually below 50%, depending on the input and output voltages, and the quiescent current of the regulator. The efficiency of a linear regulator can be estimated by Efficiency = Vout/Vin * 100%, if the quiescent current is very small. From the equation, at a certain Vout, the higher the input voltage is, the lower the efficiency is. Below is a comparison of PNMini vs. LM7805.

How does it achieve high efficiency at light load? At light load, the switching noise become significant. Instead of always switching, PNMini enters a mode called "Burst Mode", meaning that it switches for a certain amount of time, and then stops switching. When the output voltage drops below a certain level, it switches again. In this way, the switching loss is reduced at light load, thus the efficiency is improved.

What kind of protections does PNMini have? PNMini is a very robust design, it has over voltage protection, thermal shutdown protection, and short circuit protection. The way it protects itself from damage from a short circuit is by a technique called "cycle-by-cycle current limiting" - if the current exceeds a certain level, PNMini will cut the PWM waveform of the current cycle thus limits the current from growing.

What about the other specifications such as line regulation, load regulation, start up, transient response, and output voltage ripple? Don't worry! The PNMini solution is FULLY tested. It's not something you get from eBay and get nothing but a board. You get comprehensive test data on each of the specification!!

PNMini Thermal Image at Vin=12V, Vout=3.3V, Iout=2A, front

PNMini Thermal Image at Vin=12V, Vout=3.3V, Iout=2A, back

*Full datasheet link: *

https://drive.google.com/file/d/0B0aPceJUD-kdNFlKcldxS0lBUDA/edit?usp=sharing