DC1757A - Demo Manual

DEMO MANUAL DC1757A
LTC3789EGN
High Efficiency
12V/12A Buck-Boost Converter
DESCRIPTION
Demonstration circuit 1757A is a high efficiency synchronous buck-boost DC/DC converter with a 6V to 36V
input voltage range. It can supply a 12A maximum load
current with a 12V output. The demo board features the
LTC®3789EGN controller. The constant frequency current
mode architecture allows a phase-lockable frequency of up
to 600kHz, while an optional output current feedback loop
provides support for applications such as battery charging.
With a wide input range, wide output range and seamless
transfers between operation modes, the LTC3789 is ideal
for automotive, telecom, distributed DC power systems
and battery-powered applications.
The light load operation mode of the converter is determined with the MODE/PLLIN pin. Use JP2 jumper to
select pulse-skipping mode or forced continuous mode
(CCM) operation. The switching frequency is pre-set
at about 200kHz. The converter can also be externally
synchronized to an external clock through the MODE/
PLLIN pin (PLLIN terminal on the board). To shut down
the converter, force the RUN pin below 1.2V (JP1: OFF).
The power good output (PGOOD terminal) is low when the
output voltage is outside of the ±10% regulation window.
Design files for this circuit board are available at
http://www.linear.com/demo
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
PARAMETER
(TA = 25°C)
CONDITIONS
VALUE
Input Voltage Range
6V to 36V
Output Voltage, VOUT
VIN = 6V to 36V, IOUT = 0A to 12A
12V ±2%
Maximum Output Current, IOUT
VIN = 6V to 36V, VOUT = 12V
12A
Typical Output Ripple
VIN = 36V, IOUT = 12A (20MHz BW)
109mVP–P
Typical Efficiency
VIN = 12V, VOUT = 12V, IOUT = 12A
97.9%
Typical Switching Frequency
200kHz
QUICK START PROCEDURE
Demonstration circuit 1757A is easy to set up to evaluate the performance of the LTC3789. Refer to Figure 1 for
the proper measurement equipment setup and follow the
procedure below:
1. With power off, connect the input power supply to VIN
(6V to 36V) and GND (input return).
2. Connect the 12V output load between VOUT and GND
(Initial load: no load).
3. Connect the DVMs to the input and outputs.
4. Turn on the input power supply and check for the proper
output voltages. VOUT should be 12V ±2%.
5. Once the proper output voltages are established, adjust the loads within the operating range and observe
the output voltage regulation, ripple voltage and other
parameters.
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DEMO MANUAL DC1757A
QUICK START PROCEDURE
Note: When measuring the output or input voltage ripple, do not use the long ground lead on the oscilloscope
probe. See Figure 2 for the proper scope probe technique.
Short, stiff leads need to be soldered to the (+) and (–)
terminals of an output capacitor. The probe’s ground ring
needs to touch the (–) lead and the probe tip needs to
touch the (+) lead.
Additional Notes:
1. On DC1757 board, two Coilcraft XAL1010 inductors are
used in series instead of one larger inductor, for optimal
size and performance. You may use a single inductor,
such as Coilcraft SER2915L-332KL, if that is preferred.
2. Usually, the worst case efficiency at full load is at 6VIN.
The board can deliver more output power at higher VIN.
3. R2 is needed for additional/constant output current
limit only.
Figure 1. Proper Measurement Equipment Setup
+
VOUT
–
COUT
GND
Figure 2. Measuring Output Voltage Ripple
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DEMO MANUAL DC1757A
QUICK START PROCEDURE
100
98
EFFICIENCY (%)
96
94
92
90
88
86
VIN = 6V
VIN = 12V
VIN = 24V
VIN = 36V
84
82
80
0
1
2
3
4
5
6
7
8
LOAD CURRENT (A)
9
10
11
12
Figure 3. Efficiency vs load current (VO = 12V, CCM)
PARTS LIST
ITEM
QTY
REFERENCE
PART DESCRIPTION
MANUFACTURER/PART NUMBER
CAP., C0G, 100pF, 50V, 10% 0603
AVX, 06035A101KAT2A
Required Circuit Components
1
1
CC1
2
1
CC2
CAP., X7R, 0.01μF, 50V, 10% 0603
AVX, 06035C103KAT2A
3
2
CSS, C15
CAP., X7R, 0.1μF, 50V, 10% 0603
AVX, 06035C104KAT2A
4
1
C11
CAP., NPO, 68pF, 50V, 10% 0603
AVX, 06035A680KAT2A
5
1
C10
CAP., X5R, 2.2μF, 10V, 10% 0603
AVX, 0603ZD225KAT2A
6
1
C24
CAP., X7R, 1μF, 16V, 20% 0603
AVX, 0603YC105MAT2A
7
2
CIN1, CIN2
CAP., Alum, 270μF, 50V, 20%
SUN Electronics, 50ME270WX+T
8
2
COUT1, COUT2
CAP., OS-CON, 330μF, 16V, 20%
SANYO, 16SEP330M+T
9
6
C16, C17, C19-C21, C28
CAP., X7R, 22μF, 16V, 20% 1210
AVX, 1210YC226MAT2A
10
2
C4, C22
CAP., X7R, 0.22μF, 16V, 20% 0603
AVX, 0603YC224MAT2A
11
5
C9, C14, C25-C27
CAP., X7R, 3.3μF, 50V, 20% 1210
AVX, 12105C335MAT2A
12
1
C18
CAP., X5R, 10μF, 6.3V, 20% 1206
AVX, 12066D106MAT2A
13
2
D4, D7
DIODE, SCHOTTKY 1A, 60V POWERDI123
DIODE INC., DFLS160-7
14
2
D5, D6
DIODE, SCHOTTKY 3A, 40V SMA
DIODE INC., B340A-13-F
15
1
D8
DIODE, ZENER 5.1V 350MW SOT23-3
DIODE INC., BZX84C5V1-7-F
dc1757af
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DEMO MANUAL DC1757A
PARTS LIST
16
2
L1, L2
Inductor, 1.5μH
COILCRAFT, XAL1010-152ME
17
3
Q2, Q4, Q6
Mosfet N-channel
INFINEON, BSC027N04LS G
18
3
Q3, Q5, Q9
Mosfet N-channel
INFINEON, BSC010NE2LS
19
1
RFB1
RES., CHIP., 113k, 0.1W, 1% 0603
YAGEO, RC0603FR-07113KL
20
1
RFB2
RES., CHIP., 8.06k, 0.1W, 1% 0603
YAGEO, RC0603FR-078K06L
21
3
R18, R19, R32
Sensor Res., 0.01, 1W, 1% 2512
VISHAY, WSL2512R0100FEA
22
1
R2
Sense RES 0.003Ω, 1W, 1% 2512 SMD
YAGEO, PR2512FKF070R003L
23
6
R3, R4, R9, R10, R13, R14
RES., CHIP., 100, 0.1W, 1% 0603
YAGEO, RC0603FR-07100RL
24
1
R5
RES., CHIP, 5.1, 0.1W, 5% 0805
YAGEO, RC0805JR-075R1L
25
1
R7
RES., CHIP., 100k, 0.1W, 1% 0603
YAGEO, RC0603FR-07100KL
26
1
R8
RES., CHIP., 10, 0.1W, 5% 0603
YAGEO, RC0603JR-0710RL
27
1
R26
RES., CHIP., 10, 0.1W, 5% 0805
YAGEO, RC0805JR-0710RL
28
6
R1, R11, R17, R23, R25, R27
RES., CHIP., 0 1% 0603
YAGEO, RC0603FR-070RL
29
1
R20
RES., CHIP., 0 2512
TEPRO, RN5326
30
1
R16
RES., CHIP., 1k, 0.1W, 1% 0603
YAGEO, RC0603FR-071KL
31
3
RC, R21, R24
RES., CHIP., 10k, 0.1W, 1% 0603
YAGEO, RC0603FR-0710KL
32
1
R30
RES., CHIP., 33.2k, 0.1W, 1% 0603
YAGEO, RC0603FR-0733K2L
33
1
R31
RES., CHIP., 12.1k, 0.1W, 1% 0603
YAGEO, RC0603FR-0712K1L
34
1
U1
I.C.,Volt. Reg.
Linear Tech., LTC3789EGN#PBF
Additional Demo Board Circuit Components:
1
0
CF1, CF, C7, C8 (OPT)
CAP., 0603
2
0
C23, C29-C32, C35 (OPT)
CAP., 1210
3
0
C12, C13 (OPT)
CAP., 1206
4
0
Q7, Q8 (OPT)
Mosfet
5
0
R6, R12, R15, R22 (OPT)
RES., 0603
6
0
R28, R29 (OPT)
RES., CHIP., 1206
Hardware-For Demo Board Only
1
2
JP1, JP2
HEADER, 3 PIN, 0.079 SINGLE ROW
SAMTEC, TMM-103-02-L-S
2
2
3
4
XJP1, XJP2B
SHUNT, .079" CENTER
SAMTEC, 2SN-BK-G
J1, J2, J3, J4
Connector, Banana Jack
Keystone, 575-4
4
5
4
TP1, TP2, TP3, TP7
TESTPOINT, TURRET, .061" pbf
MILL-MAX, 2308-2-00-80-00-00-07-0
6
TP4, TP5, TP6, TP10-TP12
TESTPOINT, TURRET, .094" pbf
MILL-MAX, 2501-2-00-80-00-00-07-0
6
4
MTGS AT 4 CORNERS
STAND-OFF, NYLON 0.5"
KEYSTONE, 8833(SNAP ON)
dc1757af
4
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.
A
B
C
D
TP6
TP5
TP11
TP4
CSS
0.1uF
EXTVCC
PLLIN
3
JP2
MODE
R31
12.1K
41.2K
TP10
5
R16 1K
CCM
PULSE SKIP
TP12
OFF
OPT
RFB1
113K
3
2
1
R25
0
R22
OPT
INTVCC
CF
OPT
VOS+
CC2
OPT
C8
R14
100
OPT
VIN+
VOUT
100
100
0.01uF
C7
R10
R9
R13
100
10K
R21
10K
RC
CC1
C10
2.2uF
2. INSTALL SHUNTS AS SHOWN.
1. ALL RESISTORS ARE IN OHMS, 0603.
ALL CAPACITORS ARE IN MICROFARADS, 0603.
4
3
2
1
14
13
12
11
10
9
8
7
6
5
C11
68pF 4
100pF
NOTE: UNLESS OTHERWISE SPECIFIED
R24
10K
INTVCC
D8
BZX84C5V1
R15
CF1 OPT
RFB2 8.06K
JP1 VIN+
RUN
1
R30
ON
2
ITH
SS
SGND
PGOOD
R7
100K
INTVCC
4
IOSENSE-
IOSENSE+
ILIM
VOUTSNS
VINSNS
RUN
FREQ
MODE/PLLIN
SGND
ITH
SENSE1-
SENSE1+
SS
VFB
TRIM
SW2
TG2
BOOST2
BG2
EXTVCC
INTVCC
VIN
BG1
PGND
BOOST1
TG1
SW1
PGOOD
LTC3789EGN
U1
R3 100
15
16
17
18
19
20
21
22
23
24
25
26
27
28
0
R4
1uF
100
0805
R26 10
16V
C24
INTVCC
G
3
L1 1.5uH
C12
(OPT)
1206
R28
(OPT)
1206
R18
0.01
1W
R19
0.01
1W
D5
B340A
XAL1010-152ME
VIN+
R1 0
R6 OPT
VOUT
C22
0.22uF
16V
6.3V
D7
DFLS160
C18 10uF
G
Q4
BSC027N04LS
Q7 (OPT)
C4
0.22uF
16V
R12 OPT
D4
DFLS160
R27 0
R11
R23 0
R17 0
5.1
R5
Q2
Q6
BSC027N04LS
C15
0.1uF
50V
3
D
S
D
S
1.5uH
CUSTOMER NOTICE
R29
(OPT)
C13
(OPT)
D6
B340A
C28
C21
C20
C19
C17
C16
22uF
16V
1210
C14
3.3uF
50V
(OPT)
1210
2
2
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AN D
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
CHARLIE Z.
APP ENG.
SCALE = NONE
HZ
PCB DES.
__
ECO
CIN1
270uF
50V
+
1
330uF
16V
+ COUT2
VOUT
CIN2
270uF
50V
+
J4
TP1
TP2
VOS+
R8
10
J3
J2
TP7
J1
TP3
DATE
GND
VOS-
VOS+
12V @ 12A MAX
VOUT
GND
GND
6V - 36V
VIN
VIN+
CHARLIE Z. 6-9-11
APPROVED
DATE:
1
SHEET
LTC3789EGN
DEMO CIRCUIT 1757A
Friday, July 08, 2011
IC NO.
1
OF
1
2
REV.
HIGH EFFICIENCY 12V / 12A BUCK-BOOST CONVERTER
N/A
SIZE
B
C
D
1630 McCarthy Blvd.
A
Milpitas, CA 95035
Phone: (408)432-1900www.linear.com
Fax: (408)434-0507
LTC Confidential-For Customer Use Only
PRODUCTION
DESCRIPTION
REVISION HISTORY
TECHNOLOGY
330uF
16V
+ COUT1
2
REV
TITLE: SCHEMATIC
1W
2512
R2 0.003
R20 0
APPROVALS
C31
C30
C29
C23
(OPT)
1210
C32
LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A
CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS ;
HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY T O
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.
R32
0.01
1W
G
Q9
Q5
BSC010NE2LS
C35
3.3uF
50V
(OPT)
1210
VOUT1
XAL1010-152ME
L2
Q3
BSC010NE2LS
Q8
(OPT)
G
C9
C25
C26
C27
3.3uF
50V
1210
D
S
D
S
5
DEMO MANUAL DC1757A
SCHEMATIC DIAGRAM
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5
DEMO MANUAL DC1757A
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
dc1757af
6
Linear Technology Corporation
LT 1111 • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900
●
FAX: (408) 434-0507 ● www.linear.com
© LINEAR TECHNOLOGY CORPORATION 2011
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