APW7136A/B/C
Typical Application Circuits
VIN
C1
4.7µF
OFF ON
L1
22µH
6 VIN
LX 1
2
GND
OVP 5
APW7136
4
EN
FB 3
VOUT
VIN
L1
C2
1µF Up to 8
WLEDs
C1
4.7µF
22µH
6 VIN
LX 1
2
GND
OVP 5
100Hz~100KHz
APW7136
4
EN
FB 3
R1
12Ω
Duty=100%, ILED=20mA
Duty=0%, LED off
VOUT
C2
1µF Up to 8
WLEDs
R1
12Ω
Figure 1. Typical 8 WLEDs Application
VIN
L1
22µH
Figure 2. Brightness control using a PWM
signal applies to EN
VOUT
C1
4.7µF
6 VIN
LX 1
2
GND
OVP 5
OFF ON
APW7136
4
EN
FB 3
PWM
brightness
3.3V
0V
control Duty=100%, LED off
Duty=0%, ILED=20mA
VADJ
R3
120K
R4
10K
C2
1µF
R2
10K
C3
0.1µF
Up to 8
WLEDs
R1
12Ω
R2
=
VREF
⋅
VADJ,MAX
ILED,MAX ⋅ R3 + VADJ,MIN
⋅ ILED,MAX + VREF ⋅ ILED,MIN
− ILED,MIN ⋅R3 − VADJ,MAX
− VADJ,MIN ⋅ ILED,MIN − VREF
⋅ ILED,MAX
R1 =
VREF
⋅ 1 +
R2
R3
−
R2
R3
⋅
V ADJ
,MIN
ILED ,MAX
Figure 3. Brightness control using a filtered PWM signal
VIN
4.5V~6V
C1
10µF
OFF ON
L1
10µH
6 VIN
LX 1
2
GND
OVP 5
APW7136
4
EN
FB 3
C2
10µF
VOUT
9 Strings
total
R1
1.4Ω
0603
Figure 4. Circuit for driving 27 WLEDs
Copyright © ANPEC Electronics Corp.
8
Rev. A.2 - Jan., 2008
www.anpec.com.tw