eem2am
Banned
Hello,
i have designed an offline LED driver.
it is flyback.
the LED current needs filtering,
-however, placing a series inductor with the LEDs makes the power stage phase lag too long, and results in instability (oscillation in LED current)
Therefore, i have skimped on LED current filtration , and am settling for a 8mA peak to peak oscillation at 100KHz (switching freq) on the LED current......
LED current oscillation......pink=current; green = DC Bus
Here is a close up of this LED current
Here is the schematic:
I would be very surprised if this 8mA pk to pk is bad, since this picture shows what the current looks like in a fluorescent lamp....and they get by without getting banned by the EMC authorities....
i have designed an offline LED driver.
it is flyback.
the LED current needs filtering,
-however, placing a series inductor with the LEDs makes the power stage phase lag too long, and results in instability (oscillation in LED current)
Therefore, i have skimped on LED current filtration , and am settling for a 8mA peak to peak oscillation at 100KHz (switching freq) on the LED current......
LED current oscillation......pink=current; green = DC Bus
Here is a close up of this LED current
Here is the schematic:
I would be very surprised if this 8mA pk to pk is bad, since this picture shows what the current looks like in a fluorescent lamp....and they get by without getting banned by the EMC authorities....