Datasheet

CCRACGEVB
http://onsemi.com
4
Figure 4. Straight Dimmable LED Driver (120 VAC example)
Cap−Drop LED Driver Topology, Non−dimming (120 &
230 VAC Example):
The Cap-Drop circuit is selected for high efficiency and
a low BOM cost.
To set up the CCRACGEVB for the Cap-Drop LED driver
non-dimming topology, place jumpers according to Table 4.
Figure 6 & Figure 7 depict the schematics with the
evaluation board reference designators. Appendix D shows
the 120 VAC example and Appendix E provides its 230 VAC
counterpart.
Table 4. JUMPERS PLACED ONTO THE EVB
Jumpers in Place Reference Data
J2, J13, J19, J20, J25, J22, J26 Appendix D (120 VAC)
J2, J13, J19, J20, J22, J24 Appendix E (230 VAC)
The operation of the Cap-Drop circuit is very similar to the
straight LED circuit with the advantage of improved
efficiency because the AC voltage is reduced to be a little
over the forward voltage of the LED string.
Inrush Current Limiter
The Inrush Current Limiter (Figure 5) is incorporated to
reduce the surge current if power is connected at the peak of
the AC input. At turn on, the 6.8 KW resistor will limit the
current as the Darlington MJB5742 will be off and the 33 mF
capacitor will appear as a short. As the capacitor charges the
Darlington will turn on and provide a low impedance
bypass.
Figure 5. Inrush Current Limiter