MIC3230 Datasheet, PDF (12/20 Pages) Micrel Semiconductor – Constant Current Boost Controller for Driving High Power LEDs

Micrel, Inc.
MIC3230/1/2
Figure 6. IS pin and V_RCS (Ch1 = Switch Node, Ch2 = IS pin,
Ref1 = V_CS)
Design Procedure for a LED Driver
Symbol Parameter
Input
V_IN
Input Voltage
I_IN
Input current
Min
Nom
Max Units
8
12
14
V
2
A
LEDs
V_F
V_OUT
I_LED
I_PP
PWMD
OVP
Output
Number of LEDs
Forward voltage of LED
Output voltage
LED current
Required I Ripple
PWM Dimming
Output over voltage
protection
5
6
7
3.2
3.5
4.0
V
16
21
28
V
0.33
0.35
0.37
A
40
mA
0
100
%
30
V
F_SW
eff
V_DIODE
System
Switching frequency
Efficiency
Forward drop of schottky
diode
500kHz
80
%
0.6
V
Table 2. Design example parameters
January 2009
12
M9999-011409-A