1
dc1547bf
DEMO MANUAL DC1547B
Description
LT3757AEDD
High Efficiency Boost
Converter
Demonstration circuit 1547B features the LT
®
3757AEDD
in a 400kHz BOOST converter circuit, designed for a 12V
output from a 3.1V to 9V input voltage range.
The LT3757A operates over an input range of 2.9V to
40V, suitable for applications from single-cell lithium-ion
battery portable electronics up to high voltage automotive
and industrial power supplies. It also exhibits low shut-
down quiescent current of 1µA, making them an ideal fit
for battery-operated systems. Thanks to a novel FBX pin
architecture, the LT3757A can be connected directly to
a divider from either the positive output or the negative
output to ground. It also packs many popular features
performance summary
such as soft-start, input undervoltage lockout, adjustable
frequency and synchronization in a small 10-lead MSOP
package or a 3mm × 3mm QFN package.
The LT3757A 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 1547B.
Design files for this circuit board are available at
http://www.linear.com/demo/DC1547B
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.
Specifications are at TA = 25°C
PARAMETER CONDITIONS MIN TYP MAX UNITS
Input Voltage Range 3.1 9 V
Output Voltage 11.64 12 12.36 V
Maximum Output Current 1.5 A
Switching Frequency 360 400 440 kHz
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dc1547bf
DEMO MANUAL DC1547B
Quick start proceDure
Demonstration circuit 1547B is easy to set up to evaluate
the performance of the LT3757AEDD. Refer to Figure 1
for proper measurement equipment setup and follow the
procedure below:
NOTE. When measuring the input or output voltage ripple,
care must be taken to avoid a long ground lead on the
oscilloscope probe. Measure the input or output voltage
ripple by touching the probe tip directly across the VIN or
VOUT and GND terminals. See Figure 2 for proper scope
probe technique.
1. Place JP1 on the ON position.
2. With power off, connect the input power supply to VIN
and GND.
3. Turn on the power at the input.
NOTE. Make sure that the input voltage does not exceed
the maximum input voltage.
4. Check for the proper output voltages.
NOTE. If there is no output, temporarily disconnect the
load to make sure that the load is not set too high.
Once the proper output voltages are established, adjust
the loads within the operating range and observe the
output voltage regulation, ripple voltage, efficiency and
other parameters.
Figure1. Proper Measurement Equipment Setup
+
–
+ –
+
–
LOAD
VOUT
IOUT
+
–
+ –
+
–
SUPPLY
POWER VIN
IIN
3
dc1547bf
DEMO MANUAL DC1547B
Quick start proceDure
Figure2. Measuring Input or Output Ripple
Figure3. Boost Converter Efficiency at 5VIN
V
IN
GND
LOAD CURRENT (mA)
100
EFFICIENCY (%)
100
98
94
90
86
96
92
88
84
80
82
1100700
DC1547B F03
1500900500 1300300
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DEMO MANUAL DC1547B
parts List
ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER
Required Circuit Components
1 4 C1, C3, C4, C5 CAP., X5R, 22µF, 16V, 20%, 1210 Murata, GRM32ER61C226KE20L
2 1 C10 CAP., X5R, 4.7µF, 10V, 20%, 0805 Taiyo Yuden, LMK212BJ475MG-T
3 1 C11 CAP., X7R, 4.7nF, 50V, 10%, 0603 TDK, C1608X7R1H472K080AD
4 1 C12 CAP., C0G, 100pF, 50V, 5%, 0603 TDK, C1608C0G1H101J080AA
5 1 C13 CAP., X7R, 0.1µF, 25V, 10%, 0603 TDK, C1608X7R1E104K080AA
6 1 D1 DIODE, 2A SMT SCHOTTKY BARRIER PowerDI123 DIODES INC., DFLS220L-7
7 1 L1 INDUCTOR, 2.2µH 20% VISHAY, IHLP4040DZER2R2M01
8 1 Q1 SILICON N-CHANNEL POWER MOS FET, LFPAK RENESAS., RJK0328DPB-01#J0
9 1 R1 RES., CHIP, 130k, 1/10W, 1%, 0603 VISHAY, CRCW0603130KFKEA
10 2 R2, R6 RES., CHIP, 20.0k, 1/10W, 1%, 0603 VISHAY, CRCW060320K0FKEA
11 2 R3, R4 RES., CHIP, 100k, 1/10W, 1%, 0603 VISHAY, CRCW0603100KFKEA
12 1 R5 RES., CHIP, 0.008Ω, 1W, 1%, 0815 THIN FILM, RL3720WT-R008-F
13 1 R7 RES., CHIP, 30.9k, 1/10W, 1%, 0603 VISHAY, CRCW060330K9FKEA
14 1 R8 RES., CHIP, 10k, 1/10W, 5%, 0603 VISHAY, CRCW060310K0JNEA
15 1 R9 RES., CHIP, 0Ω , 1/16W, 0603 VISHAY, CRCW06030000Z0EA
16 1 U1 I.C., LT3757AEDD, DFN 10 (3mm X 3mm) LINEAR TECH., LT3757AEDD#PBF
Additional Demo Board Circuit Components
1 1 CIN1 CAP., CE-LX, 100µF, 16V, SIZE 6.6 X 6.6 SUN ELECTRONIC, 16CE100LX
Hardware: For Demo Board Only
17 E1-E7 TESTPOINT, TURRET, .094", PBF MILL-MAX, 2501-2-00-80-00-00-07-0
2 1 JP1 3 PIN 0.079 SINGLE ROW HEADER SULLINS, NRPN031PAEN-RC
3 1 XJP1 SHUNT, .079" CENTER SAMTEC, 2SN-BK-G
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DEMO MANUAL DC1547B
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.
Figure4. DC1547B Demo Circuit Schematic
schematic Diagram
VOUT
12V @ 1.5A
VCC
SYNC
OFF
GND
RUN
GND
3.1V - 9V
VIN
GND
ON
SIZE
DATE:
IC NO. REV.
SHEET OF
TITLE:
TECHNOLOGY Fax: (408)434-0507
Milpitas, CA 95035
Phone: (408)432-1900
1630 McCarthy Blvd.
LTC Confidential-For Customer Use Only
CUSTOMER NOTICE
LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A
CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS;
HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO
VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL
APPLICATION. COMPONENT SUBSTITUTION AND PRINTED
CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT
PERFORMANCE OR RELIABILITY. CONTACT LINEAR
TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SCHEMATIC
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
www.linear.com
1
DEMO CIRCUIT 1547B
Thursday, April 16, 2015 11
High Efficiency Boost Converter
N/A
LT3757AEDD
SIZE
DATE:
IC NO. REV.
SHEET OF
TITLE:
TECHNOLOGY Fax: (408)434-0507
Milpitas, CA 95035
Phone: (408)432-1900
1630 McCarthy Blvd.
LTC Confidential-For Customer Use Only
CUSTOMER NOTICE
LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A
CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS;
HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO
VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL
APPLICATION. COMPONENT SUBSTITUTION AND PRINTED
CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT
PERFORMANCE OR RELIABILITY. CONTACT LINEAR
TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SCHEMATIC
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
www.linear.com
1
DEMO CIRCUIT 1547B
Thursday, April 16, 2015 11
High Efficiency Boost Converter
N/A
LT3757AEDD
SIZE
DATE:
IC NO. REV.
SHEET OF
TITLE:
TECHNOLOGY Fax: (408)434-0507
Milpitas, CA 95035
Phone: (408)432-1900
1630 McCarthy Blvd.
LTC Confidential-For Customer Use Only
CUSTOMER NOTICE
LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A
CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS;
HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO
VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL
APPLICATION. COMPONENT SUBSTITUTION AND PRINTED
CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT
PERFORMANCE OR RELIABILITY. CONTACT LINEAR
TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SCHEMATIC
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
www.linear.com
1
DEMO CIRCUIT 1547B
Thursday, April 16, 2015 11
High Efficiency Boost Converter
N/A
LT3757AEDD
E2E2
R6
20K
R6
20K
C4
22uF
16V
C4
22uF
16V
C12
100pF
C12
100pF
L1
2.2uH
L1
2.2uH
Q1
RJK0328DPB
Q1
RJK0328DPB
4
5
2 31
D1
DFLS220L-7
D1
DFLS220L-7
R7
30.9K
R7
30.9K
C5
22uF
16V
C5
22uF
16V
C10
4.7uF
10V
C10
4.7uF
10V
E4E4
E6E6
R3
100K
R3
100K
R1
130K
1%
R1
130K
1%
E5E5
R9
0
R9
0
E7E7
JP1JP1
1
2
3
C11
4.7nF
C11
4.7nF
LT3757AEDD
U1
LT3757AEDD
U1
VC
1
FBX
2
SS
3
RT
4
SYNC
5
SENSE 6
GATE 7
INTVcc 8
VIN 10
SHDN/UVLO
9
GND
11
R5
0.008
1W
R5
0.008
1W
R8
10K
R8
10K
R4
100K
R4
100K
+CIN1
100uF
16V
+CIN1
100uF
16V
R2
20.0K
1%
R2
20.0K
1%
C3
22uF
16V
C3
22uF
16V
E3E3
E1E1
C1
22uF
16V
C1
22uF
16V
C13
0.1uF
C13
0.1uF
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dc1547bf
DEMO MANUAL DC1547B
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com
LINEAR TECHNOLOGY CORPORATION 2015
LT 0515 • PRINTED IN USA
DEMONSTRATION BOARD IMPORTANT NOTICE
Linear Technology Corporation (LT C ) 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
