Linear Technology DC1817B Quick setup guide

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DEMO MANUAL DC1817B
Description
LT3798
Isolated No Opto-Coupler
Flyback Controller with PFC
Demonstration circuit 1817B is an off-line isolated flyback
converterfeaturingtheLT
®
3798.Thedemoboardprovidesa
singleconstant-voltageoutputof24Vat2A.Itisoptimized
to operate over a wide AC input voltage range (90VAC to
265VAC, 47Hz to 63Hz). Output voltage accuracy stays
within ±5% over the whole input voltage and load range. It
provides a high power factor (>0.95) enabling the design
to be used worldwide. It is also designed to comply with
the IEC 61000-3-2 Class D harmonics standard and the
EN55015B conducted EMI standard.
The LT3798 controls an isolated flyback converter in
boundary mode, suitable for applications with voltage or
current regulation. Its novel sensing scheme delivers a
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
well regulated output voltage or current to the secondary
side without the use of an opto-coupler.
TheLT3798isavailableinalowprofile,thermallyenhanced
16-lead MSOP package.
The LT3798 data sheet gives a complete description of
the part, operation and application information. The data
sheet must be read in conjunction with this quick start
guide for demo circuit 1817B.
Design files for this circuit board are available at
http://www.linear.com/demo/DC1817B
(TA= 25°C)
PARAMETER CONDITIONS MIN TYP MAX
Input Range Line Frequency, 47Hz to 63Hz 90VAC 120VAC 265VAC
Output Voltage 24V
Efficiency 90VAC to 265VAC, 2A IOUT 87%
Power Factor 24V/2A Output, 90VAC to 265VAC 0.99 0.98 0.95

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DEMO MANUAL DC1817B
Quick start proceDure
Figure 1. Proper Measurement Equipment Setup
IMPORTANT NOTE TO CUSTOMERS:
HIGH VOLTAGES ARE PRESENT ON THE DEMO
CIRCUIT, AND CAN LEAD TO LETHAL INJURIES
TO HUMAN BODY. ONLY QUALIFIED PERSONNEL
SHOULD OPERATE IT. IT IS STRONGLY RECOM-
MENDED TO USE SAFETY GLASSES AND AN
ISOLATION TRANSFORMER.
NOTE: Improper components replacement on the demo
circuit can cause performance deteriorations, circuit
malfunction, property damage, and even life threatening
injuries.ContactLinearTechnologyapplicationsengineers
for proper component replacement.
Demonstration circuit 1817B is easy to set up to evaluate
theperformanceoftheLT3798.RefertoFigure1forproper
measurementequipment setup and follow thisprocedure:
1. Connect an adjustable load between + and – output
terminals.
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 (265VAC).
4. Check for the proper output voltage.
Once the proper output voltage is established, adjust the
inputvoltageand/ortheloadandobservetheoutputvoltage
regulation, efficiency, power factor and other parameters.

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DEMO MANUAL DC1817B
Quick start proceDure
Figure 2. Efficiency vs Input Voltage Figure 3. VOUT vs Load Current
Figure 4. Power Factor vs Input Voltage
Figure 5. 120VAC (PF = 0.99) Figure 6. 230VAC (PF = 0.97)
Input Line Voltage and Current
IIN(AC)
(1A/DIV)
VIN(AC)
(200V/DIV)
5ms/DIV 5ms/DIV
VIN (AC-RMS)
90
EFFICIENCY (%)
90
95
100
250
85
80
75 110 130 150 170 190 210 230
270
dc1817b F02
2A LOAD
1A LOAD
LOAD (A)
0
V
OUT
(V)
23
24
25
22
21
20 0.25 0.5 0.75 1 1.25 1.5 1.75
2
dc1817b F03
120VIN
240VIN
VIN (AC-RMS)
90
POWER FACTOR
0.96
0.98
1
250
0.94
0.92
0.90 110 130 150 170 190 210 230
270
dc1817b F04
2A LOAD

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DEMO MANUAL DC1817B
Figure 7. 120VAC (VSW = 450V)
Figure 9. 120VAC
Figure 11. Output Ripple at 120VAC, 2A Load
Figure 8. 230VAC (VSW = 630V)
Switch Node Voltage
Output Current and Switch Node Voltage During Output Short
Figure 10. 230VAC
IC(VIN)
(20V/DIV)
IOUT
(5A/DIV)
VSW
(200V/DIV)
VSW
(100V/DIV)
VOUT
(1V/DIV)
Figure 12. Output Ripple at 230VAC, 2A Load
Quick start proceDure
2µs/DIV
200ms/DIV
2ms/DIV
2µs/DIV
200ms/DIV
2ms/DIV

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DEMO MANUAL DC1817B
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 20% 250V/275VAC ECQ-UL PANASONIC, ECQUAAF104M
3 1 C2 CAP, FILM, 0.22µF 20% 400V PANASONIC ECQE4224KF
4 1 C3 CAP, 10µF 20% 50V ALUM RUBYCON 50YXJ10M 5X11
5 1 C6 CAP, 0805 0.1µF 10% 50V X7R TDK, C2012X7R1H104K
6 1 C7 CAP, 0805 2.2µF 10% 50V X5R TDK, C2012X5R1H225K
7 1 C8 CAP, 0805 4.7µF 20% 16V X5R AVX 0805YD475MAT2A
8 2 C10, C11 CAP, 1000µF 20% 35V ELEC NIPPON CHEMI-CON ELXV350ETD102MK30S
9 1 C13 CAP, 1210 2.2nF, 5% 630V U2J MURATA, GRM32A7U2J222JW31D
10 1 C20 CAP, 2.2nF 20% 400V, Y5U TYPE "Y1" VISHAY, 440LD22-R
11 2 C12, C21 CAP, 0805 22pF ±0.25pF 50V NP0 AVX, 08055A220CAT2A
12 2 C23, C25 CAP, 1210 10µF 20% 35V X5R MURATA, GRM32ER7YA106KA12L
13 1 C24 CAP, 1206 47pF 10% 630V NPO AVX, 1206CA470KAT1A
14 1 D1 DIODE, ULTRA FAST RECTIFIER CENTRAL SEMI, CMR1U-10M
15 1 D2 DIODE, FAST SWITCHING DIODES INC, BAV20W-7-F
16 1 D5 DIODE, SUPER BARRIER RECIFIER 20A DIODES INC SBR20A200CTB
17 1 D8 DIODE, SWITCH 100V 400MW SOD123 DIODES INC, 1N4148W-7-F
18 1 F1 FUSE, 2.5A, FAST ACTING COOPER BUSSMAN, SS-5F-3.15A
19 1 L2 CHOKE, D CODE DOUBLE CHOKE TDK/EPCOS, B82731H2701A030
20 1 L1 INDUCTOR, 1mH, 0.78A RADIAL 1000µH TDK, TSL1315RA-102JR78-PF
21 1 Q1 MOSFET, N-CH 650V 21A D2PAK INFINEON, IPB60R165CP
22 2 R1, R2 RES, 1206 100k 1% 1/4W VISHAY CRCW1206100KFKEA
23 1 R3 RES, 0805 100k 1% 1/8W VISHAY, CRCW0805100KFKEA
24 1 R4 RES, 0805 5.49k 1% 1/8W VISHAY, CRCW08055K49FKEA
25 1 R5 RES, 0805 68Ω 5% 1/8W VISHAY, CRCW080568R0JKEA
26 1 R25 RES, 0805 20Ω 1% 1/8W VISHAY, CRCW080520R0FKEA
27 1 R7 RES, 0805 33k 5% 1/8W VISHAY, CRCW080533K0JNEA
28 1 R8 RES, 0.03Ω 1/4W 1% 1206 SMD VISHAY, WSL1206R0300FEA
29 1 R9 RES, 1210 510Ω 5% 1/2W VISHAY, CRCW1210510RJNEA
30 2 R10, R11 RES, 1206 499k 1% 1/4W VISHAY CRCW1206499KFKEA
31 1 R18 RES, 0805 10k 1% 1/8W VISHAY, CRCW080510K0FKEA
32 1 R19 RES, 0805 40.2k 1% 1/8W VISHAY, CRCW080540K2FKEA
33 1 R20 RES, 0805 31.6k 1% 1/8W VISHAY, CRCW080531K6FKEA
34 1 R37 RES, 0805 0Ω 5% 1/8W VISHAY, CRCW08050000Z0EA
35 2 R27, R28 RES, 1206 510Ω 5% 1/4W VISHAY CRCW1206510KJKEA
36 1 R32 RES, 1210 51k 5% 1/2W VISHAY, CRCW121051KOJNEA
37 1 R35 RES, 0805 2.4M 5% 1/8W VISHAY, CRCW08052M40JNEA
38 1 R36 RES, 0805 301k 1% 1/8W VISHAY, CRCW0805301KFKEA
39 1 R38 RES, 0805 24.9k 1% 1/8W VISHAY, CRCW080524K9FKEA

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DEMO MANUAL DC1817B
ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER
40 1 T1 XFMR, FLYBACK WÜRTH ELECTONIK, 750811248
41 1 U1 IC, ISOLATED FLYBACK CONTROLLER LINEAR TECHNOLOGY LT3798EMSE#PBF
42 1 V1 VARISTOR, 320V RMS 13.5MM RADIAL VISHAY VDRS10P320BSE
Additional Circuit Components
1 0 R23 RES, 0805, OPTION OPTION
Hardware/Components (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)
parts List

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DEMO MANUAL DC1817B
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
Figure 13. DC1817B Demo Circuit Schematic
5
5
4
4
3 3
2
2
1
1
DD
C C B B
AA
90 - 265VAC
1206
1206
1206
FILM
24V/ 2A
0805
+
-
N L
INTVCC
INTVCC
R18 10k
1%
+
C11 1000uF 35V
R4 5.49K
1%
-
+
B1 HD06
21
3 4
V1
VDRS10P320BSE
R1
100k
1%
R20
31.6k
R5 68
R38
24.9k
C2
0.22uF
400V
R36
301k1%
R3
100k
1%
C7
2.2uF
J1
1
2
R27 510 1210
R9 510 1210
R32 51K
1210
C6
0.1uF
50V
R11
499k
1%
C24
47pF 1206 630V
C8 4.7uF
16V
R2
100k
1%
+
C10
1000uF
35V
D5
SBR20A200CTB
C23
10uF 35V 1210
D1
CMR1U-10M
R8 0.03
1206
L2
27mH
B82731H2701A030
2
3
1
4
C13 2.2nF 1210
C21
22pF
C12
22pFC25
R35
2.4M 1%
R25
20 1%
D8
1N4148
F1 250V, 2.5A
R28 510 1210
R10
499k
1%
T1
750811248
2
4
6
8
9
10
3
1
5
11
J2
1
2
Q1
IPB60R165CP
+
C3
10uF 50V
C20
2200pF
Y1
D2 BAV20W
L1 1mH
1 2
R7
33K
CAC1 0.1uF
275VAC
R19
40.2k
1%
R37
0
R23
OPT
U1 LT3798EMSE
10
9
16
2
1
12
17
15
3
14
5
13
8
7
6
4
11
DCM
FBVINSENSE
CTRL2
CTRL1 EN_UVLO
GND
SENSE
CTRL3
GATE
OVP
INTVCC
COMP-
COMP+
VC
VREF
VIN

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DEMO MANUAL DC1817B
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
[phone] ●FAX: [phone] ●www.linear.com
 LINEAR TECHNOLOGY CORPORATION 2012
LT 1114 REV A • PRINTED IN USA
DEMONSTRATION BOARD IMPORTANT NOTICE
Linear Technology Corporation (LT C) provides the enclosed product(s) under the following AS IS conditions:
Thisdemonstrationboard (DEMO BOARD) kit being sold orprovidedbyLinear TechnologyisintendedforuseforENGINEERING 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. LT C 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

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