Datasheet

R15 C11
FLTR2
R2
R7
DIM
R9
C14
R1
R3
D7
Q1
R8
V+
C7 C8
V
CC
R22
D8
R13
R14
VLED+
VLED±
L1
C5
R4
V+
LINE
NEUTRAL
INPUT EMI FILTER AND RECTIFIER CIRCUIT
D1
D3
D4
D5
C3
DIM
V
CC
FLTR2
R11
C10
R10
TRIAC HOLDING
CIRCUIT
R16
C12
Q3
Q4
R20
C1
D6
C6
L2
R6
R24
C2
R5
D2
T1
C13
+
LM3448
9
10
11
12
13
4
5
6
7
8
BLDR
ASNS
ISNS
DIM
COFF
GND
VCC
FLTR1
GND
FLTR2
14
3NC
NC
15
2SWSW
16
1
SW
SW
COFF
COFF
R18
C9
COFF CURRENT
SOURCE
V
CC
V
AUX
R17
V
AUX
C15
Q5
D12
OVP CIRCUIT
FLTR2
R19
D13
V
AUX
Q2
D9
VCC AUXILIARY BIAS CIRCUIT
R12
D11
D10
C4
V
CC
PGND
SGND
Design Guide www.ti.com
13 Design Guide
Figure 26. Evaluation Board Schematic
The following section explains how to design an isolated flyback converter using the LM3448. Refer to the
LM3448 Phase Dimmable Offline LED Driver with Integrated FET Data Sheet (SNOSB51) for specific
details regarding the function of the LM3448 device. All reference designators refer to the Evaluation
Board Schematic in Figure 26 unless otherwise noted.
14
AN-2090 LM3448 -120VAC, 6W Isolated Flyback LED Driver SNOA554C–October 2011–Revised May 2013
Submit Documentation Feedback
Copyright © 2011–2013, Texas Instruments Incorporated