This is pretty much the stock implementation of the LT3439 ultra low noise switcher -- promises maybe 100uV or less noise with the filters shown -- I use 70 uH with an 85kHz switching frequency -- only because I have a bunch of 70uH inductors laying around. I put a zener on the front input as the LT3439 is limited to 20V input -- the power supply could also be used in an automotive application. The drop resistor value is TBA.
The LT3439 is TSSOP so I had some boards made with a solder mask -- these should be back in a week or so. The LT3439 is cooled with the copper pour on the top surface. Resistors and caps are 0603, but I use through-hole electrolytics as they are so much easier to mount than smt's.
An externally hosted image should be here but it was not working when we last tested it.
The LT3439 is TSSOP so I had some boards made with a solder mask -- these should be back in a week or so. The LT3439 is cooled with the copper pour on the top surface. Resistors and caps are 0603, but I use through-hole electrolytics as they are so much easier to mount than smt's.
An externally hosted image should be here but it was not working when we last tested it.
