3.3V to 30V DC/DC converter using SN6505A
Recently I’v got my samples of SN6505A, it’s a really nice IC, so I decided to make a simple DC/DC converter to get familiar with it. What I like in this chip is that it can operate on input voltage as low as 2,5V – that makes it great for battery devices. It’s also nice, that it’s a very minimalist design – on primary side all what is needed is decoupling capacitor. One disadvantage is that it doesn’t have a feedback loop.
To increase efficiency, SN6505A can operate with more developed versions of transformers, but I used the simplest configuration – one coil on each side. The circuit is presented below. The chip as well as other components is mounted on the bottom side of the PCB.
Current consumption is 330mA at 3V3, this could be probably easily reduced by using different transformator.
Unfortunately I din’t have neither suitable transformer nor appropriate coil to wind it. I made my own transformator from a solenoid coil as a secondary side, and 10 loops of 0,7mm wire as a primary side. The inductances are respectively 2u5H and 11m5H. Maybe it’s not the most beautiful transformer and EMI will be terrible, but for this simple project it works ok.
Summarizing, that’s a nice chip and probably I will use it in some of my projects in the future.
For more detail: 3.3V to 30V DC/DC converter using SN6505A