Just wanted to say THANK YOU for designing the MAX4466 board with such robust supply noise rejection.
I’ve been working on a project for a few months now. It’s a wall-sized realtime audio spectrum display, and I’ve spent lots of money and time designing and building it. Countless hours cutting and welding aluminum, vacuforming polycarbonate lenses, routing traces in eagle cad, pulling and soldering a few hundred feet of wire, etc… It has been intense and the piece goes on display in two weeks.
Up to this point I had been programming the µc on a breadboard with normal leds, which was working fine, but the actual project needs to be bright, so it uses 49 10w leds and constant-current drivers. These are all switched via shift-registered tip122 transistors with a 12v supply, and the same supply feeds a 5v regulator on the µc board. The switching is noisy, and when I plugged in the spark fun electret breakout (part# BOB-09964) I had been prototyping with, I almost had a stroke because the output signal looked like a horrible jagged mess of ramps and periodic ringing. The project had turned into a satanic feedback matrix that was emitting a train of chaotic incomprehensible transients.
I was about to give up and cry myself to sleep, but I realized I had a MAX4466 board in my drawer, and plugged it in just to make sure I’d tried everything. The project started working flawlessly. There was no noise in the audio at all! I can’t begin to describe the feeling of relief that I felt upon plugging it in.
Anyway, I just wanted to say thanks for the engineering that went into that great little board.