DEMO MANUAL DC1947A
LT3799-1
Offline Isolated Flyback LED
Driver with PFC
DESCRIPTION
Demonstration circuit 1947A is an off-line isolated flyback
LED driver featuring
LTC
®
3799-1
. The demo board provides
a single constant current output of 1A over an LED string
voltage from 30V to 50V. It is optimized to operate over a
wide AC input voltage range (90VAC to 277VAC, 47Hz to
63Hz). It provides a high power factor (>0.9) enabling a
single design to be used worldwide. It is also designed to
comply with the IEC 61000-3-2 Class C harmonics standard
and the EN55015B conducted EMI standard.
The LT3799-1 controls an isolated flyback converter in
boundary mode. Its novel current sensing scheme deliv-
ers a well-regulated output current to the secondary side
without using an opto-coupler. Open- and shorted-LED
protection ensures long term reliability.
The LT3799-1 is available in a low profile, thermally-
enhanced 16-lead MSOP package.
The LT3799-1 data sheet gives a complete description
of the device, operation and application information. The
data sheet must be read in conjunction with this quick
start guide for demo circuit 1947A.
Design files for this circuit board are available at
http://www.linear.com/demo
L,
LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. All other trademarks are the property of their respective owners.
PERFORMANCE SUMMARY
PARAMETER
Input Voltage Range
Output Current I
OUT
Output Voltage
Open LED Voltage
(Note 1)
CONDITIONS
(T
A
= 25°C)
MIN
90
30
54
TYP
230
1
48
50
MAX
277
UNITS
VAC
A
V
V
Line Frequency, 47Hz to 63Hz
V
IN
= 120VAC, V
LED
= 48V
Note 1: For applications with low LED string voltage, FB pin divider resistor R4 and output clamp D9 can be adjusted to reduce the open voltage limit.
See “Protection from Open LED and Shorted LED Faults” section in the data sheet for detail.
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DEMO MANUAL DC1947A
QUICK START PROCEDURE
IMPORTANT NOTE TO CUSTOMERS
HIGH VOLTAGES ARE PRESENTED ON THE DEMO CIRCUIT,
AND CAN LEAD TO LETHAL INJURIES TO HUMAN BODY.
ONLY QUALIFIED PERSONNEL SHOULD OPERATE IT. IT IS
STRONGLY RECOMMENDED TO USE SAFETY GLASSES
AND AN ISOLATION TRANSFORMER.
NOTE. IMPROPER COMPONENTS REPLACEMENT ON THE
DEMO CIRCUIT CAN CAUSE PERFORMANCE DETERIORA-
TIONS, CIRCUIT MALFUNCTION, PROPERTY DAMAGE,
AND EVEN LIFE-THREATENING INJURIES. CONTACT
LINEAR TECHNOLOGY APPLICATIONS ENGINEERS FOR
PROPER COMPONENT REPLACEMENT.
Demonstration circuit 1947A is easy to set up to evalu-
ate the performance of the LT3799-1. Refer to Figure 1
for proper measurement equipment setup and follow the
procedure below:
1. Connect a 1A LED string with forward voltage less than
50V, but greater than 30V, between LED
+
and LED
–
ter-
minals.
2. With power off, connect the input power supply to line
(L) input and neutral (N) input.
3. Turn on the power at the input.
NOTE. Make sure that the input voltage does not exceed
the maximum input voltage (277VAC).
4. Check for the proper output current.
Once the proper output currents are established, adjust the
input voltage and/or the load and observe the output current
regulation, efficiency, power factor and other parameters.
Figure 1. Proper Measurement Equipment Setup
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DEMO MANUAL DC1947A
PARTS LIST
ITEM
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
QTY
1
1
1
1
2
1
1
1
1
1
1
1
1
2
1
1
1
1
1
1
1
2
1
1
1
1
1
2
1
1
2
1
1
1
2
1
1
1
REFERENCE
B1
CAC1
C2
C3
C6, C7
C8
C9
C10, C11
C13
C20
C21
C23
D1
D2, D8
D3
D4
D9
F1
L1
L2
Q1
R1, R2
R3
R4
R5
R7
R8
R10, R11
R18
R19
R20, R27
R21
R23
R25
R32, R33
T1
U1
V1
PART DESCRIPTION
RECTIFIER, BRIDGE 600V, 0.8A
CAP 0.1μF 310V, 20%
,
,
CAP FILM, 0.22μF 450V, 10%
,
,
CAP 10μF 20%, 50V, ALUM
,
,
CAP X7R, 0.01μF 50V, 10%, 0805
,
,
CAP X5R, 4.7μF 16V, 20%, 0805
,
,
CAP C0G, 47pF 50V, 10%, 0805
,
,
CAP ELEC., 330μF 63V, 20%
,
,
CAP U2J, 1.5nF 250V, 5%, 0805
,
,
CAP 2.2nF 10%, TYPE "Y1"
,
,
CAP C0G, 4.7pF 50V, 0805
,
,
CAP X7R, 1μF 100V, 10%, 1206
,
,
DIODE, ULTRA FAST RECTIFIER
DIODE, FAST SWITCHING
DIODE, 3A Ultra-Fast REC., Power-DI-5
DIODE, TVS, 600W, 170V, SMB
DIODE, TVS, 600W, 48V, SMB
FUSE, 2.5A
INDUCTOR, 1mH,
CHOKE, D Code Double Choke
XSTR, MOSFET, N-CHANNEL 650V
RES, CHIP 249k, 1%, 1/4W, 1206
.,
RES, CHIP 200k, 1%, 1/8W, 0805
.,
RES, CHIP 9.31k, 1%, 1/8W, 0805
.,
RES, CHIP 150, 1%, 1/8W, 0805
.,
RES, CHIP 10k, 1%, 1/8W, 0805
.,
RES, CHIP 0.03, 1/4W, 1%, 1206
.,
RES, CHIP 499k, 1%, 1/4W, 1206
.,
RES, CHIP 100k, 1%, 1/8W, 0805
.,
RES, CHIP 40.2k, 1%, 1/8W, 0805
.,
RES, CHIP 20k, 1%, 1/8W, 0805
.,
RES, CHIP 0, 1/8W, 0805
.,
RES, CHIP 3.48k, 1%, 1/8W, 0805
.,
RES, CHIP 20, 5%, 1/8W, 0805
.,
RES, CHIP 200k, 1%, 1/2W, 1210
.,
XFMR, FLYBACK
IC., Isolated Flyback Controller
VARISTOR, 385V
MANUFACTURER/PART NUMBER
DIODES INC., HD06-T
VISHAY, BFC233922104
RUBYCON, 450MPH224K
RUBYCON, 50YXJ10M 5X11
Murata, GRM216R71H103KA01D
AVX, 0805YD475MAT2A
AVX, 08055A470KAT
RUBYCON, 63ZL330MEF
Murata, GRM21A7U2E152JW31D
VISHAY, 440LD22-R
AVX, 08055A4R7BAQ2A
AVX 12061C105KAT2A
CENTRAL SEMI.CMR1U-10M
DIODES INC., BAV20W-7-F
DIODES INC., PDU340-13
DIODES INC., SMBJ170A-13-F
DIODES INC. SMBJ48A-13-F
BUSSMAN, SS-5H-2.5A
TDK, TSL1315RA-102JR78-PF
EPCOS, B82731H2701A030
INFINEON, IPB60R165CP
VISHAY, CRCW0805249KFKEA
VISHAY, CRCW0805200KFKEA
VISHAY, CRCW08059K31FKEA
VISHAY, CRCW0805150RFKEA
VISHAY, CRCW080510KFKEA
VISHAY, WSL1206R0300FEA
VISHAY, CRCW1206499KFKEA
VISHAY, CRCW0805100KFKEA
VISHAY, CRCW080540K2FKEA
VISHAY, CRCW080520KFKEA
VISHAY, CRCW08050000Z0EA
VISHAY, CRCW08053K48FKEA
VISHAY, CRCW080520R0JKEA
VISHAY, CRCW1210200KFKEA
WÜRTH ELECTONIK, 750817251
LINEAR TECH. LT3799EMSE-1#PBF
Stackpole Electronic, Inc. CV385K10R
Required Circuit Components
dc1947af
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