Mar 1, 2010 #1 E eem2am Banned Joined Jun 22, 2008 Messages 1,179 Helped 37 Reputation 74 Reaction score 24 Trophy points 1,318 Activity points 0 hello, I have to drive leds of 24V and then 3v with the same 26V rail (from the same power supply). So therefore, due to extremes of duty cycle, this is only practical in voltage mode. -No off-the-shelf LED driver IC can manage this job. But i cannot find a voltage mode PWM controller witha Duty Cycle extending to 0.95 or more. All i can find is UCC25701 http://www.datasheetcatalog.org/datasheet/texasinstruments/ucc25701.pdf ...but this is an expensive part and i just need a basic Voltage Mode PWM controller (8 or 10 pins) Does any reader know of such a part?
hello, I have to drive leds of 24V and then 3v with the same 26V rail (from the same power supply). So therefore, due to extremes of duty cycle, this is only practical in voltage mode. -No off-the-shelf LED driver IC can manage this job. But i cannot find a voltage mode PWM controller witha Duty Cycle extending to 0.95 or more. All i can find is UCC25701 http://www.datasheetcatalog.org/datasheet/texasinstruments/ucc25701.pdf ...but this is an expensive part and i just need a basic Voltage Mode PWM controller (8 or 10 pins) Does any reader know of such a part?
Mar 1, 2010 #2 F frankliner Member level 5 Joined Sep 9, 2009 Messages 82 Helped 12 Reputation 24 Reaction score 8 Trophy points 1,288 Activity points 1,679 Did you look into the part i suggested before? **broken link removed**
Mar 17, 2010 #3 E eem2am Banned Joined Jun 22, 2008 Messages 1,179 Helped 37 Reputation 74 Reaction score 24 Trophy points 1,318 Activity points 0 yes thankyou, but it is too expensive