1
dc1947af
DEMO MANUAL DC1947A
DESCRIPTION
LT3799-1
Offline Isolated Flyback LED
Driver with PFC
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.
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
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
(TA = 25°C)
PARAMETER CONDITIONS MIN TYP MAX UNITS
Input Voltage Range Line Frequency, 47Hz to 63Hz 90 230 277 VAC
Output Current IOUT VIN = 120VAC, VLED = 48V 1 A
Output Voltage 30 48 50 V
Open LED Voltage (Note 1) 54 V
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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dc1947afb
DEMO MANUAL DC1947A
QUICK START PROCEDURE
Figure 1. Proper Measurement Equipment Setup
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.
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dc1947af
DEMO MANUAL DC1947A
QUICK START PROCEDURE
Figure 5. VIN = 120VAC Figure 6. VIN = 230VAC
Figure 7. VIN = 120VAC Figure 8. VIN = 230VAC
Input Line Voltage and Current
Switch Node Voltage
Figure 2. Efficiency vs Input Voltage Figure 4. Power Factor vs Input Voltage
Figure 3. IOUT vs Input Voltage
VIN (AC-RMS)
90
EFFICIENCY (%)
60
110 130 150 170 190 210 230 250 270
DC1947a F02
80
100
50
70
90
VIN (AC-RMS)
90
ILED (A)
110 130 150 170 190 210 230 250 270
DC1947a F03
1.0
1.4
0.6
0.8
1.2
VIN (AC-RMS)
90
POWER FACTOR
0.92
110 130 150 170 190 210 230 250 270
DC1947a F04
0.96
1.00
0.90
0.94
0.98
DC1947a F05
VIN AC
200V/DIV
IIN AC
500mA/DIV
5ms/DIV DC1947a F06
VIN AC
200V/DIV
IIN AC
500mA/DIV
5ms/DIV
DC1947a F07
VSW
100V/DIV
5μs/DIV DC1947a F08
VSW
100V/DIV
5μs/DIV
4
dc1947afb
DEMO MANUAL DC1947A
QUICK START PROCEDURE
Output Voltage and Switch Node Voltage During Output Open
Output Current and Switch Node Voltage During Output Short
Figure 9. VIN = 120VAC Figure 10. VIN = 230VAC
Figure 11. VIN = 120VAC Figure 12. VIN = 230VAC
DC1947a F09
VOUT
10V/DIV
VSW
200V/DIV
200ms/DIV DC1947a F10
VOUT
10V/DIV
VSW
200V/DIV
200ms/DIV
DC1947a F11
200ms/DIV
IOUT
10A/DIV
IC VIN
100V/DIV
VSW
200V/DIV
DC1947a F12
IOUT
10A/DIV
IC VIN
100V/DIV
VSW
200V/DIV
200ms/DIV
5
dc1947af
DEMO MANUAL DC1947A
PARTS LIST
ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER
Required Circuit Components
1 1 B1 RECTIFIER, BRIDGE 600V, 0.8A DIODES INC., HD06-T
2 1 CAC1 CAP, 0.1μF, 310V, 20% VISHAY, BFC233922104
3 1 C2 CAP, FILM, 0.22μF, 450V, 10% RUBYCON, 450MPH224K
4 1 C3 CAP, 10μF, 20%, 50V, ALUM RUBYCON, 50YXJ10M 5X11
5 2 C6, C7 CAP, X7R, 0.01μF, 50V, 10%, 0805 Murata, GRM216R71H103KA01D
6 1 C8 CAP, X5R, 4.7μF, 16V, 20%, 0805 AVX, 0805YD475MAT2A
7 1 C9 CAP, C0G, 47pF, 50V, 10%, 0805 AVX, 08055A470KAT
8 1 C10, C11 CAP, ELEC., 330μF, 63V, 20% RUBYCON, 63ZL330MEF
9 1 C13 CAP, U2J, 1.5nF, 250V, 5%, 0805 Murata, GRM21A7U2E152JW31D
10 1 C20 CAP, 2.2nF, 10%, TYPE "Y1" VISHAY, 440LD22-R
11 1 C21 CAP, C0G, 4.7pF, 50V, 0805 AVX, 08055A4R7BAQ2A
12 1 C23 CAP, X7R, 1μF, 100V, 10%, 1206 AVX 12061C105KAT2A
13 1 D1 DIODE, ULTRA FAST RECTIFIER CENTRAL SEMI.CMR1U-10M
14 2 D2, D8 DIODE, FAST SWITCHING DIODES INC., BAV20W-7-F
15 1 D3 DIODE, 3A Ultra-Fast REC., Power-DI-5 DIODES INC., PDU340-13
16 1 D4 DIODE, TVS, 600W, 170V, SMB DIODES INC., SMBJ170A-13-F
17 1 D9 DIODE, TVS, 600W, 48V, SMB DIODES INC. SMBJ48A-13-F
18 1 F1 FUSE, 2.5A BUSSMAN, SS-5H-2.5A
19 1 L1 INDUCTOR, 1mH, TDK, TSL1315RA-102JR78-PF
20 1 L2 CHOKE, D Code Double Choke EPCOS, B82731H2701A030
21 1 Q1 XSTR, MOSFET, N-CHANNEL 650V INFINEON, IPB60R165CP
22 2 R1, R2 RES, CHIP., 249k, 1%, 1/4W, 1206 VISHAY, CRCW0805249KFKEA
23 1 R3 RES, CHIP., 200k, 1%, 1/8W, 0805 VISHAY, CRCW0805200KFKEA
24 1 R4 RES, CHIP., 9.31k, 1%, 1/8W, 0805 VISHAY, CRCW08059K31FKEA
25 1 R5 RES, CHIP., 150, 1%, 1/8W, 0805 VISHAY, CRCW0805150RFKEA
26 1 R7 RES, CHIP., 10k, 1%, 1/8W, 0805 VISHAY, CRCW080510KFKEA
27 1 R8 RES, CHIP., 0.03, 1/4W, 1%, 1206 VISHAY, WSL1206R0300FEA
28 2 R10, R11 RES, CHIP., 499k, 1%, 1/4W, 1206 VISHAY, CRCW1206499KFKEA
29 1 R18 RES, CHIP., 100k, 1%, 1/8W, 0805 VISHAY, CRCW0805100KFKEA
30 1 R19 RES, CHIP., 40.2k, 1%, 1/8W, 0805 VISHAY, CRCW080540K2FKEA
31 2 R20, R27 RES, CHIP., 20k, 1%, 1/8W, 0805 VISHAY, CRCW080520KFKEA
32 1 R21 RES, CHIP., 0, 1/8W, 0805 VISHAY, CRCW08050000Z0EA
33 1 R23 RES, CHIP., 3.48k, 1%, 1/8W, 0805 VISHAY, CRCW08053K48FKEA
34 1 R25 RES, CHIP., 20, 5%, 1/8W, 0805 VISHAY, CRCW080520R0JKEA
35 2 R32, R33 RES, CHIP., 200k, 1%, 1/2W, 1210 VISHAY, CRCW1210200KFKEA
36 1 T1 XFMR, FLYBACK WÜRTH ELECTONIK, 750817251
37 1 U1 IC., Isolated Flyback Controller LINEAR TECH. LT3799EMSE-1#PBF
38 1 V1 VARISTOR, 385V Stackpole Electronic, Inc. CV385K10R
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dc1947afb
DEMO MANUAL DC1947A
PARTS LIST
ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER
Additional Demo Board Circuit Components
1 0 R22(OPT) RES, CHIP., 0805
Hardware—For Demo Board Only
1 2 J1, J2 TERMINAL BLOCK, 2 POSITION WEIDMULLER, 1715250000
2 4 MH1 to MH4 STAND-OFF, NYLON,0.25" KEYSTONE, 8831(SNAP ON)
7
dc1947af
DEMO MANUAL DC1947A
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representa-
tion that the interconnection of its circuits as described herein will not infringe on existing patent rights.
SCHEMATIC DIAGRAM
5
5
4
4
3
3
2
2
1
1
D D
C C
B B
A A
90 - 277VAC
1206
1206
1206
FILM
N/A
NOTES: UNLESS OTHERWISE SPECIFIED,
1. ALL CAPACITORS AND RESISTORS ARE 0805.
1A / 48V
0805
CAUTION: HANDLING HIGH VOLTAGE INVOLVES RISK TO LIFE. COMPLY WITH SAFETY REGULATIONS!
LED+
LED-
NL
REVISION HISTORY
DESCRIPTION DATEAPPROVEDECO REV
WEI G.PRODUCTION
208-15-12
REVISION HISTORY
DESCRIPTION DATEAPPROVEDECO REV
WEI G.PRODUCTION
208-15-12
REVISION HISTORY
DESCRIPTION DATEAPPROVEDECO REV
WEI G.PRODUCTION
208-15-12
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48W OFFLINE ISOLATED FLYBACK
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LT3799EMSE-1
DC1947A
LED CONTROLLER WITH ACTIVE PFC
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LT3799EMSE-1
DC1947A
LED CONTROLLER WITH ACTIVE PFC
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DC1947A
LED CONTROLLER WITH ACTIVE PFC
R22
OPT
R22
OPT
R10
499k
1%
R10
499k
1%
R5
150
R5
150
V1
CV385K10R
V1
CV385K10R
R25
20
R25
20
C13
1.5nF
0805
250V
C13
1.5nF
0805
250V
C23
1uF
1206
100V
C23
1uF
1206
100V
C8
4.7uF
16V
C8
4.7uF
16V
+
C3
10uF
50V
+
C3
10uF
50V
D3
PDU340
D3
PDU340
L2
27mH
B82731H2701A030
L2
27mH
B82731H2701A030
2
3
1
4
C6
10nF
C6
10nF
R3
200k
1%
R3
200k
1%
R33
200k
1210
R33
200k
1210
R8
0.03
1206
R8
0.03
1206
D1
CMR1U-10M
D1
CMR1U-10M
R2
249k
1%
R2
249k
1%
R27
20k
0805
R27
20k
0805
R7
10k
R7
10k J2J2
1
2
C7
10nF
C7
10nF
R19
40.2k
1%
R19
40.2k
1%
D8
BAV20W
D8
BAV20W
R11
499k
1%
R11
499k
1%
R4
9.31k
1%
R4
9.31k
1%
Q1
IPB60R165CP
Q1
IPB60R165CP
+
C10
330uF
63V
+
C10
330uF
63V
R20
20k
1%
R20
20k
1%
J1J1
1
2
C9
47pF
C9
47pF
U1
LT3799EMSE-1
U1
LT3799EMSE-1
DCM 10
FB 9
VINSENSE
16
CTRL2
2
CTRL1
1
NC
12
GND
17
SENSE 15
CTRL3
3
GATE 14
FAULT
5
INTVCC 13
COMP- 8
COMP+ 7
CT
6
VREF
4
VIN 11
CAC1 0.1uF
310VAC
CAC1 0.1uF
310VAC
D2
BAV20W
D2
BAV20W
D4
SMBJ170A
D4
SMBJ170A
D9
SMBJ48A
D9
SMBJ48A
C2
0.22uF
450VDC
C2
0.22uF
450VDC
R18
100k
1%
R18
100k
1%
T1
750817251
T1
750817251
4
210
11
8
9
1
6
5
3
L1
1mH
L1
1mH
1 2
F1
300V, 2.5A
SS-5H-2.5A
F1
300V, 2.5A
SS-5H-2.5A
-
+
B1
HD06
-
+
B1
HD06
2 1
3 4
+
C11
330uF
63V
+
C11
330uF
63V
R23
3.48K
R23
3.48K
C20
2200pF
Y1
C20
2200pF
Y1
C21
4.7pF
C21
4.7pF R32
200k
1210
R32
200k
1210
R21
0
R21
0
R1
249k
1%
R1
249k
1%
8
dc1947afb
DEMO MANUAL DC1947A
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com
© LINEAR TECHNOLOGY CORPORATION 2013
LT 0113 • PRINTED IN USA
DEMONSTRATION BOARD IMPORTANT NOTICE
Linear Technology Corporation (LTC) provides the enclosed product(s) under the following AS IS conditions:
This demonstration board (DEMO BOARD) kit being sold or provided by Linear Technology is intended for use for ENGINEERING DEVELOPMENT
OR EVALUATION PURPOSES ONLY and is not provided by LTC for commercial use. As such, the DEMO BOARD herein may not be complete
in terms of required design-, marketing-, and/or manufacturing-related protective considerations, including but not limited to product safety
measures typically found in finished commercial goods. As a prototype, this product does not fall within the scope of the European Union
directive on electromagnetic compatibility and therefore may or may not meet the technical requirements of the directive, or other regulations.
If this evaluation kit does not meet the specifications recited in the DEMO BOARD manual the kit may be returned within 30 days from the date
of delivery for a full refund. THE FOREGOING WARRANTY IS THE EXCLUSIVE WARRANTY MADE BY THE SELLER TO BUYER AND IS IN LIEU
OF ALL OTHER WARRANTIES, EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING ANY WARRANTY OF MERCHANTABILITY OR FITNESS
FOR ANY PARTICULAR PURPOSE. EXCEPT TO THE EXTENT OF THIS INDEMNITY, NEITHER PARTY SHALL BE LIABLE TO THE OTHER FOR
ANY INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES.
The user assumes all responsibility and liability for proper and safe handling of the goods. Further, the user releases LTC from all claims
arising from the handling or use of the goods. Due to the open construction of the product, it is the user’s responsibility to take any and all
appropriate precautions with regard to electrostatic discharge. Also be aware that the products herein may not be regulatory compliant or
agency certified (FCC, UL, CE, etc.).
No License is granted under any patent right or other intellectual property whatsoever. LTC assumes no liability for applications assistance,
customer product design, software performance, or infringement of patents or any other intellectual property rights of any kind.
LTC currently services a variety of customers for products around the world, and therefore this transaction is not exclusive.
Please read the DEMO BOARD manual prior to handling the product. Persons handling this product must have electronics training and
observe good laboratory practice standards. Common sense is encouraged.
This notice contains important safety information about temperatures and voltages. For further safety concerns, please contact a LTC applica-
tion engineer.
Mailing Address:
Linear Technology
1630 McCarthy Blvd.
Milpitas, CA 95035
Copyright © 2004, Linear Technology Corporation
