Datasheet

NCL30100
http://onsemi.com
19
Figure 38. ILED and Vin Waveform if No Dimming is Used
Figure 39. Efficiency Measurement for the
Demoboard (V
f
= 3.2 Nominal)
77
78
79
80
81
82
83
84
7 8 9 10111213141516
INPUT VOLTAGE (V)
EFFICIENCY (%)
DC Voltage Efficiency
(No Bridge Rectifier)
Figure 39 represents the efficiency of the converter
driving a single LED at a nominal current of 690 mA. The
addition of the AC bridge rectifier contributes addition
losses into the circuit and it is recommended to us low
forward voltage schottky rectifiers to minimize power
dissipation in the AC rectification stage.
Figure 40. I
LED
Current Dependence on Input
DC Voltage (No Bridge Rectifier is Used)
620
630
640
650
660
670
680
690
7 8 9 1011121314151
6
INPUT VOLTAGE (V)
CURRENT (mA)
LED Current Variation
MR 16 Evaluation Board Information
A specific two sided demo board was designed to fit with
the MR 16 form factor. The schematic is almost the same for
both, but the PWM dimming control circuitry has been
removed. If the same components are used, the operation
frequency will be slightly higher due to the lower pin
capacitance because the dimming transistor contribution is
removed.