Datasheet

IN
EN
SW
D
FB
FREQ
COMP
SL22
SS
1
4
5
6
3
2
PGND
7
8
TPS61085
V
5 V ± 20%
IN
C
10 µF/
16 V
IN
C
1 µF/ 16 V
BY
L
6.8 µH
C
100 nF
SS
R
24 k
COMP
Ω
C
3.3 nF
COMP
R
15
SENSE
Ω
C
2* 10 µF/
25 V
OUT
V
500 mA
S
3S3P wLED
LW E67C
D
BZX84C 18 V
Z
R
110
LIMIT
Ω
optional
PWM
100 Hz to 500 Hz
IN
EN
SW
D
FB
FREQ
COMP
SL22
SS
1
7
5
6
3
2
4
PGND
8
TPS61085
V
5 V ± 20%
IN
C
10 µF/
16 V
IN
C
1 µF/ 16 V
BY
L
6.8 µH
C
100 nF
SS
R
24 k
COMP
Ω
C
3.3 nF
COMP
R
15
SENSE
Ω
C
2* 10 µF/
25 V
OUT
V
500 mA
S
3S3P wLED
LW E67C
D
BZX84C 18 V
Z
R
LIMIT
R1
180 kΩ
Analog Brightness Control
PWM Signal
3.3 V ~ wLED off
0 V ~ l = 30 mA (each string)
Can be used swinging from 0 V to 3.3 V
LED
R2
127 kΩ
110 Ω
optional
TPS61085
www.ti.com SLVS859A –JUNE 2008–REVISED APRIL 2012
Figure 21. Simple Application (3.3V input - f
sw
= 650 kHz) for wLED Supply (3S3P) with Adjustable
Brightness Control using a PWM Signal on the Enable Pin (with Optional Clamping Zener Diode)
Figure 22. Simple Application (3.3V input - f
sw
= 650 kHz) for wLED Supply (3S3P) with Adjustable
Brightness Control using an Analog Signal on the Feedback Pin (with Optional Clamping Zener Diode)
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