mic3230 Micrel Semiconductor, mic3230 Datasheet - Page 12

• Manufacturer Part Number: mic3230
• Description: Constant Current Boost Controller For Driving High Power Leds
• Manufacturer: Micrel Semiconductor

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