I need to develope a constant current LED Driver. The product must be portable and as small as possible. So I can not use SMPS, I have use AC/DC adapter as source. This is the AC/DC adapters output:
50 Hz, double rectification = 100 Hz clamps are seen here.
and this is the LED driver, in a single form we want to use:
In the system there are 3 LED driver like this so Max LED current is 3A. And here is the problem we have. Although, ripple level of the converter is just 40 mV over 12V DC, it causes to tremendous effect for us because in our specific application, we use this photodetector with 50 or 60 dB gain:
So, here is what I have so far:
- I have AD/DC adapter, Power lines are 50Hz in here, so 100 Hz ripples comes from double rectification.
- The lab Team said any ripple or noise on above 100KHz is fine they can filter it out.