Diodes ZXLD1374 - Manual (Page 35)

ZXLD1374
Document number: DS35032 Rev. 3 - 2
35 of 39
www.diodes.com
September 2012
© Diodes Incorporated
ZXLD1374
A Product Line of
Diodes Incorporated
Application Information
(cont.)
1.5A Buck LED Driver
In this application example, ZXLD1374 is connected
as a Buck LED driver with schematic and parts list
shown below. The LED driver is able to deliver 1.5A of
LED current to single or multiple LEDs in series with
input voltage ranged from 10V to 50V. In order to
achieve high efficiency under high LED current, Super
Barrier Rectifier (SBR) with low forward voltage is
used as free wheeling rectifier.
With only a few extra components, the ZXLD1374
LED driver is able to deliver LED power of greater
than 60W. This is suitable for applications which
require high LED power likes high power down
lighting, wall washer, automotive LED lighting etc.
Figure 46 Application Circuit of 1.5A Buck LED Driver
Bill of Material
Ref No. Value Part No. Manufacturer
U1 60V 1.5A LED driver ZXLD1374 Diodes Inc
D1 100V 3A SBR SBR3U100 Diodes Inc
L1 33µH 4.2A 744770933 Wurth Electronik
C1 100pF 50V SMD 0805/0603 Generic
C2 1µF 100V X7R SMD1206 Generic
C3 C4 C5 2.2µF 100V X7R SMD1210 Generic
R1 R2 300mΩ 1% SMD1206 Generic
R3 4.7Ω SMD1206 Generic
Typical Performance
Efficiency vs Input Voltage
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
10 15 20 25 30 35 40 45 50
Input Voltage (V)
E
ff
ici
en
cy (
%
)
1 LED VF=3.4V
3 LED VF=9.8V
5 LED VF=16V
Figure 47 Efficiency
LED Current vs Input Voltage
0
400
800
1200
1600
10 15 20 25 30 35 40 45 50
Input Voltage (V)
L
E
D
Cu
rr
ent
(
m
A)
1 LED VF=3.4V
3 LED VF=9.8V
5 LED VF=16V
Figure 48 Line Regulation