Hello! I used WEBENCH to design a buck converter that would take a 24VDC input in order to drop it down to 5VDC. After putting it together on a PCB and powering it on, I noticed the circuit was giving me a fixed output of 0.5V. I tried assembling another one on a different PCB, and had the same trouble.
Here is my schematic:
And here is my PCB layout (Upper left: View in 3D viewer; Upper right = front copper; Lower left: back copper)
As you may have noticed, the layout isn't up to spec with the datasheet (forgot to look there first) and I was wondering: does this warrant a PCB redesign?
Here's a list of things that I have tried:
- Soldering the input capacitors directly on pins 6 (GND) and 7 (VIN) (this made the circuit generate 0.5V instead of shorting 24V to 0V)
- Putting a 10K potentiometer instead of R6 and made the resistance vary (this made our 0.5V shift to about 0.49V at 10K ohms and 0.51V at 0 ohms)
- Verifying that R5 is indeed 10K ohms
Help would be greatly appreciated. Thanks!
Gabriel
