V
IN
SW
FB
EN
GND
L1
10 μH
D1
MBRM120L
C2
100 nF
(See
Note A)
C1
4.7 μF
R
S
110 Ω
V
CC
= 2.7 V to 6 V
R1
120 kΩ
R2
160 kΩ
Analog Brightness Control
3.3 V @ Led Off
0 V @Iled = 20 mA
D2
24 V
(Optional)
L1: Murata LQH4C3R3M04
D1: Motorola MBR0530
C1: Tayo Yuden JMK212BY475MG
C2: Standard Ceramic Capacitor
Copyright © 2016, Texas Instruments Incorporated
V
IN
SW
FB
EN
GND
L1
10 μH
D1
C2
1 μF
C1
4.7 μF
R
S
82 Ω
V
CC
= 2.7 V to 6 V
PWM
100 Hz to 500 Hz
D2
24 V
(Optional)
L1: Murata LQH4C100K04
D1: Motorola MBR0530
C1: Tayo Yuden JMK212BY475MG
C2: Tayo Yuden TMK316BJ105KL
Copyright © 2016, Texas Instruments Incorporated
18
TPS61040, TPS61041
SLVS413I – OCTOBER 2002 – REVISED DECEMBER 2016
www.ti.com
Product Folder Links:
TPS61040 TPS61041
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Copyright © 2002–2016, Texas Instruments Incorporated
System Examples (continued)
Figure 21. White LED Supply With Adjustable Brightness Control
Using a PWM Signal on the Enable Pin, Efficiency Approximately Equals 86% at V
IN
= 3 V, I
LED
= 15 mA
A.
A smaller output capacitor value for C2 causes a larger LED ripple.
Figure 22. White LED Supply With Adjustable Brightness Control
Using an Analog Signal on the Feedback Pin
