DC1687A - Demo Manual

DEMO MANUAL DC1687A
LTC3115EDHD-1
40V, 2A Synchronous
Buck-Boost DC/DC Converter
Description
Demonstration circuit 1687A features the LTC®3115-1, a
high voltage monolithic synchronous buck-boost converter.
The DC1687A demo board has two user selectable operating 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 voltage 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.
The demo board also has optional provisions to back
feed VCC in order to increase efficiency in some 5V output 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
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
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 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 4), or by using an oscilloscope probe tip jack.
1.Jumper and PS1 settings to start:
PS1 = OFF
JP1 (PWM) = fixed frequency
JP2 (RUN) = ON 4.Turn on PS1 and slowly increase voltage until the voltage at VIN is 4.0V.
5.Verify VOUT is ~5.0V.
6.VIN can now be varied between 2.7V and 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)
100
100
90
90
EFFICIENCY (%)
EFFICIENCY (%)
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.
80
70
60
50
80
70
60
LOAD = 500mA
LOAD = 1A
0
5
10
15
20
25
30
35
VIN (V)
Figure 1. DC1687A Efficiency in PWM Mode
40
50
LOAD = 100mA
LOAD = 200mA
LOAD = 300mA
0
5
10
15
20
25
30
35
40
VIN (V)
Figure 2. DC1687A Efficiency in Burst Mode Operation
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DEMO MANUAL DC1687A
quick start procedure
Figure 3. Proper Measurement Equipment Setup
GND
VIN
Figure 4. Measuring Input or Output Ripple
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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
4
4
SHUNT, .079" CENTER
SAMTEC, 2SN-BK-G
SPACER STACKING #4 SCREW NYLON .500"
KEYSTONE, 8833
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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 representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
1
2
3
4
E3
JP2
RUN
C5
1
2 RUN
3
VIN
+
A
JP1
1
2
3
VCC
PWM
OPT
OPT
PWM
C3
C12
1uF
50V
1206
R5
R6
1M
OPT
FIXED FREQ
SYNCH
BURST MODE
OFF
ON
GND
E4
C10
4.7uF
50V
1812
2.7V - 40V
VIN
C9
4.7uF
6.3V
0603
R7
47.5k
PWM
VCC
4
8
5
16
9
11
14
10
13
GND
RT
GND
1
6
7
3
12
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
OPT
C
SCALE = NONE
J.NOON
NC
C11
10pF
0603
DATE:
N/A
SIZE
R3
15k
C4
33pF
D
DESCRIPTION
R2
249k
R1
1M
C7
1uF
25V
0603
E2
GND
VOUT
5.0V / 2A
02-08-12
D
LTC3115EDHD-1
DEMO CIRCUIT 1687A
E
SHEET
1
40V, 2A BUCK BOOST DC / DC CONVERTER
IC NO.
DATE
02-08-12
UNLESS NOTED:
RESISTORS: OHMS, 0402, 1%
CAPACITORS: uF, 0402
C6
47uF
10V
1812
E1
J.NOON
APPROVED
E
OF
1
2
REV.
1630 McCarthy Blvd.
Milpitas, CA 95035
Phone: (408)432-1900 www.linear.com
Fax: (408)434-0507
LTC Confidential-For Customer Use Only
PRODUCTION FAB
REVISION HISTORY
TECHNOLOGY
2
-
C8
3300pF
REV
ECO
TITLE: SCHEMATIC
R4
60.4k
C2
0.1uF
VOUT
RUN
D2
B360A
APPROVALS
LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A
CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS;
HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO PCB DES.
VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL
APP ENG.
APPLICATION. COMPONENT SUBSTITUTION AND PRINTED
CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT
PERFORMANCE OR RELIABILITY. CONTACT LINEAR
TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
B
C
U1
LTC3115EDHD-1
RUN
VC
FB
PVOUT
BST2
PWM/SYNC
VCC
L1
10uH
PVCC
PVIN
VIN
BST1
CUSTOMER NOTICE
C13
0.1uF
0805
OPT
D1
PMEG2010EA
VOUT
VIN
C1
0.1uF
15
SW1
2
SW2
B
PGND
17
A
1
2
3
4
DEMO MANUAL DC1687A
Schematic Diagram
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DEMO MANUAL DC1687A
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 application engineer.
Mailing Address:
Linear Technology
1630 McCarthy Blvd.
Milpitas, CA 95035
Copyright © 2004, Linear Technology Corporation
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Linear Technology Corporation
LT 0412 • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900
●
FAX: (408) 434-0507 ● www.linear.com
 LINEAR TECHNOLOGY CORPORATION 2012
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