Linear Technology DC1687A Quick setup guide

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dc1687af
DEMO MANUAL DC1687A
Description
LTC3115EDHD-1
40V, 2A Synchronous
Buck-Boost DC/DC Converter
Demonstration circuit 1687A features the LTC
®
3115-1, a
high voltagemonolithic synchronousbuck-boost converter.
The DC1687A demo board has two user selectable operat-
ing modes: Burst Mode
®
operation and forced continuous
operation (fixed frequency PWM) (JP1). There is also an
accurate programmable RUN pin which is used to enable
the converter (JP2).
The DC1687A operates with a 2.7V to 40V input volt-
age range. The demo board has been designed with the
output voltage set to 5.0V. The LTC3115-1 incorporates a
proprietary low noise switching algorithm which optimizes
efficiency with input voltages above, below or equal to the
output voltage and ensures seamless transitions between
operating modes.
The demo board has been programmed to operate at 1MHz
in PWM mode to optimize small size with high efficiency
operation.
L, LT, LTC, LTM, µModule, Burst Mode, 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 demo board also has optional provisions to back
feed VCC in order to increase efficiency in some 5V out-
put applications. There is also a provision for an optional
Schottky diode from SW2 to VOUT for applications where
VOUT is greater than 20V and short circuit protection is
desired. Consult the data sheet for more information on
these options.
Figures 1 and 2 show typical demo board efficiency.
The LTC3115-1 data sheet has detailed information about
the operation, specifications, and applications of the part.
The data sheet should be read in conjunction with this
quick start guide.
Design files for this circuit board are available at
http://www.linear.com/demo
PARAMETER VALUE
Input Voltage Range 2.7V to 40V
VOUT 5.0V
IOUT (See Note 1) 1A For VIN ≥ 3.6V,
2A For VIN > 6V
Efficiency See Figures 1 and 2
Note 1: The Demo Board output current is a function of VIN. Please refer to the data sheet for more information
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DEMO MANUAL DC1687A
Quick start proceDure
Using short twisted pair leads for any power connections
and with all loads and power supplies off, refer to Figure 3
for the proper measurement and equipment setup. The
battery/power supply (PS1) should not be connected to
the circuit until told to do so in the procedure below.
When measuring the input or output voltage ripple, care
must be taken to avoid a long ground lead on the oscil-
loscope probe. Measure the input or output voltage ripple
by touching the probe tip directly across the VIN or VOUT
and GND terminals (see Figure 4), or by using an oscil-
loscope probe tip jack.
1. Jumper and PS1 settings to start:
PS1 = OFF
JP1 (PWM) = fixed frequency
JP2 (RUN) = ON
2. With power OFF connect the power supply (PS1) as
shown in Figure 3. If accurate current measurements
are desired (for efficiency calculation for example) then
connect an ammeter in series with the supply as shown.
The ammeter is not required however.
3. Connect a 500mA load to VOUT as shown in Figure 3
(10Ω for VOUT = 5V). Connect an ammeter if accurate
current measurement or monitoring is desired.
4. Turn on PS1 and slowly increase voltage until the volt-
age at VIN is 4.0V.
5. Verify VOUT is ~5.0V.
6. VIN cannow bevaried between 2.7Vand 40.0V. IOUT may
need to be reduced for VIN < 4V. VOUT should remain in
regulation.
7. Load current (IOUT) can also be varied. The maximum
IOUT is a function of VIN and the current limit. Consult
the data sheet for more information on IOUT vs VIN. In
general for VIN > 3.6V IOUT can be increased to 1A. For
VIN > 6V IOUT can be increased to 2A.
8. For operation in Burst Mode operation move Jumper
JP1 to burst. IOUT is limited in Burst Mode operation.
See the data sheet for more information.
9. NOTE: If VOUT drops out of regulation, check to be sure
the maximum load has not been exceeded, or that VIN
is not below the minimum value for regulation (see data
sheet)
0
100
90
80
70
60
50
5 10 15 20 25 30 35 40
EFFICIENCY (%)
VIN (V)
LOAD = 1A
LOAD = 500mA
0
100
90
80
70
60
50
5 10 15 20 25 30 35 40
EFFICIENCY (%)
VIN (V)
LOAD = 300mA
LOAD = 200mA
LOAD = 100mA
Figure 1. DC1687A Efficiency in PWM Mode Figure 2. DC1687A Efficiency in Burst Mode Operation
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dc1687af
DEMO MANUAL DC1687A
Quick start proceDure
Figure 3. Proper Measurement Equipment Setup
Figure 4. Measuring Input or Output Ripple
GND VIN
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DEMO MANUAL DC1687A
parts List
ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER
Required Circuit Components
1 2 C1, C2 CAP, CER, 0.10µF, 16V, X7R, ±20%, 0402 TDK, C1005X7R1C104M
2 1 C4 CAP, CER, 33pF, 50V, C0G, 5%, 0402 TDK, C1005C0G1H330J
3 1 C6 CAP, CER, 47µF, 10V, 20%, X5R, 1812 TDK, C4532X5R1A476M
4 1 C7 CAP, CER, 1.0µF, 25V, X5R, 0603 TDK, C1608X5R1E105M
5 1 C8 CAP, CER, 3300pF, 50V, 5%, NP0, 0603 TDK, C1608C0G1H332J
6 1 C9 CAP, CER, 4.7µF, 6.3V, X5R, 20%, 0603 TDK, C1608X5R0J475M
7 1 C10 CAP, CER, 4.7µF, 50V, 20%, X7R, 1812 TDK, C4532X7R1H475M/2.00
8 1 C11 CAP, CER, 10pF, 50V, C0G, 0402 TDK, C1005C0G1H100D
9 1 C12 CAP, CER, 1.0µF, 50V, X7R, 20%, 1206 TDK, C3216X7R1H105M
10 1 C13 CAP, CER, 0.1µF, 50V, 20%, X7R, 0805 TDK, C2012X7R1H104M/0.85
11 1 L1 INDUCTOR, 10µH, ±20% COILCRAFT, MSS1048-103MLB
12 2 R1, R6 RES, 1.00MΩ, 1/16W, 1%, 0402, SMD VISHAY, CRCW04021M00FKED
13 1 R2 RES, 249kΩ, 1/16W, 1%, 0402, SMD VISHAY, CRCW0402249KFKED
14 1 R3 RES, 15.0kΩ, 1/10W, 1%, 0402, SMD PANASONIC, ERJ-2RKF1502X
15 1 R4 RES, 60.4kΩ, 1/10W, 1%, 0402, SMD PANASONIC, ERJ-2RKF6042X
16 1 R7 RES, 47.5kΩ, 1/16W, 1%, 0402, SMD VISHAY, CRCW040247K5FKED
17 1 U1 40V, 2A Buck Boost DC/DC Converter LINEAR TECHNOLOGY, LTC3115EDHD-1
Additional Demo Board Circuit Components
1 0 C3 CAP, CER, 1000PF, 50V, 20%, X7R, 0402 (OPT) TDK, C1005X7R1H102M
2 0 C5 CAP, ALUM, 150µF, 50V, 20%, RADIAL (OPT) PANASONIC, EEU-FM1H151
3 0 D1 DIODE SCHOTTKY, 20V, 1A, SOD323 (OPT) NXP SEMI, PMEG2010EA
4 0 D2 DIODE SCHOTTKY, 60V, 3A, SMA (OPT) DIODES INC.,B360A-13
5 0 R5 RES, 0402 (OPT)
Hardware For Demo Board Only:
1 4 E1–E4 TP, TURRET, 0.094", PBF MILL-MAX, 2501-2-00-80-00-00-07-0
2 2 JP1, JP2 JMP, 3-PIN 1 ROW .079CC SAMTEC, TMM-103-02-L-S
3 2 XJP1, XJP2 SHUNT, .079" CENTER SAMTEC, 2SN-BK-G
4 4 SPACER STACKING #4 SCREW NYLON .500" KEYSTONE, 8833
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DEMO MANUAL DC1687A
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
A A
B B
C C
D
D
E E
44
33
22
11
RUN
VCC
VOUT
VOUT
VCC PWM
RUN
PWM
VIN
VIN
REVISION HISTORY DESCRIPTION DATEAPPROVEDECO REV
J.NOONPRODUCTION FAB
- 2 02-08-12
REVISION HISTORY DESCRIPTION DATEAPPROVEDECO REV
J.NOONPRODUCTION FAB
- 2 02-08-12
REVISION HISTORY DESCRIPTION DATEAPPROVEDECO REV
J.NOONPRODUCTION FAB
- 2 02-08-12
SIZE
DATE:
.VER.ONCI
SHEET OF
TITLE:
APPROVALS
PCB DES.
APP ENG.
TECHNOLOGY Fax: [phone]
Milpitas, CA 95035
Phone: [phone] 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.
SCALE = NONE
www.linear.com
2
DEMO CIRCUIT 1687A
11
N/A
LTC3115EDHD-1
NC
J.NOON
02-08-12
40V, 2A BUCK BOOST DC / DC CONVERTER
SIZE
DATE:
.VER.ONCI
SHEET OF
TITLE:
APPROVALS
PCB DES.
APP ENG.
TECHNOLOGY Fax: [phone]
Milpitas, CA 95035
Phone: [phone] 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.
SCALE = NONE
www.linear.com
2
DEMO CIRCUIT 1687A
11
N/A
LTC3115EDHD-1
NC
J.NOON
02-08-12
40V, 2A BUCK BOOST DC / DC CONVERTER
SIZE
DATE:
.VER.ONCI
SHEET OF
TITLE:
APPROVALS
PCB DES.
APP ENG.
TECHNOLOGY Fax: [phone]
Milpitas, CA 95035
Phone: [phone] 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.
SCALE = NONE
www.linear.com
2
DEMO CIRCUIT 1687A
11
N/A
LTC3115EDHD-1
NC
J.NOON
02-08-12
40V, 2A BUCK BOOST DC / DC CONVERTER
FIXED FREQ
BURST MODE
PWM
SYNCH
ON
OFF
UNLESS NOTED: RESISTORS: OHMS, 0402, 1% CAPACITORS: uF, 0402
0603
RUN
D2
B360A
OPT
D2
B360A
OPT
C2 0.1uF C2 0.1uF
C11
10pF
C11
10pF
E1
VOUT
5.0V / 2A
E1
VOUT
5.0V / 2A
D1
PMEG2010EA
OPT
D1
PMEG2010EA
OPT
C1
0.1uF
C1
0.1uF
R3 15k R3 15k
R5
OPT
R5
OPT
E4
GND
E4
GND
E2
GND
E2
GND
C3
OPT
C3
OPT
C10
4.7uF
50V
1812
C10
4.7uF
50V
1812
JP1JP1
1 2
3
C12
1uF
50V
1206
C12
1uF
50V
1206
R1
1M
R1
1M
C7
1uF 25V
0603
C7
1uF 25V
0603
L1
10uH
L1
10uH
C8
3300pF
C8
3300pF
C4 33pF C4 33pF
+
C5
OPT
+
C5
OPT
C13
0.1uF
0805
C13
0.1uF
0805
R7
47.5k
R7
47.5k
U1
LTC3115EDHD-1
U1
LTC3115EDHD-1
VIN
10
PVIN
14
PVCC
11
VCC
9
RUN 1
PWM/SYNC
16
GND
5
RT
8
GND
4
PGND
17
PVOUT 3
VC 6
FB 7
BST1
13
SW1 15
BST2 12
SW2 2
C9
4.7uF 6.3V
0603
C9
4.7uF 6.3V
0603
JP2JP2
1 2
3
R2
249k
R2
249k
R4
60.4k
R4
60.4k
E3
VIN
2.7V - 40V
E3
VIN
2.7V - 40V
C6
47uF 10V
1812
C6
47uF 10V
1812
R6
1M
R6
1M
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DEMO MANUAL DC1687A
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
[phone] ●FAX: [phone] ●www.linear.com
 LINEAR TECHNOLOGY CORPORATION 2012
LT 0412 • 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
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