AN-40 Datasheet, PDF (3/3 Pages) Micrel Semiconductor – Application Note 40

Application Note 40
+VIN
3.0V to 4.2V
C1
10µF/6.3V
Taiyo Yuden
JMK212BJ106MG
L1
47µH
Murata
LQH32C470K34
R2
SHDN
1M
U1 MIC2142
5
EN
3
SW
VCC ¹
2 _{GND FB} 4
D1
MBR0530
R3
1k
C2
1µF
25V
White LEDs
R1
1.27k
Z1
16V
174Ω
C3
10µF/16V
Murata
GRM42-6X5R106K16
GND
Figure 5. Dual Mode
+VIN
3.0V to 4.2V
C1
10µF/6.3V
Taiyo Yuden
JMK212BJ106MG
L1
22µH
Murata
LQH32CN220K1
SHDN
R2
1M
U1 MIC2142
5
EN
3
SW
VCC ¹
2 _{GND FB} 4
GND
D1
MBR0530
R3
1k
C2
1µF
25V
White LEDs
R1
86.6Ω
Z1
16V
C3
10µF/16V
Murata
GRM42-6X5R106K16
DAC
R5
R4
Figure 6. Series White LED Driver with Analog Dimming Control
Summary
The demand of white and blue LEDs will dramatically in-
crease over the year due to the their low voltage, small size,
simplicity and long life-span. Micrel’s LED drivers will allow
designer to easily power these white and blue LEDs with high
efficiency, low profile components, and minimum component
counts.
Micrel
MICREL, INC. 1849 FORTUNE DRIVE SAN JOSE, CA 95131 USA
TEL + 1 [phone] FAX + 1 [phone] WEB http://www.micrel.com
This information is believed to be accurate and reliable, however no responsibility is assumed by Micrel for its use nor for any infringement of patents or
other rights of third parties resulting from its use. No license is granted by implication or otherwise under any patent or patent right of Micrel, Inc.
© 2002 Micrel, Incorporated
August 2002
3
Application Note 40