Linear Technology DC2131A Quick setup guide

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dc2131afb
DEMO MANUAL DC2131A
DESCRIPTION
LTC3623
15V, ±5A Monolithic Synchronous
Step-Down Regulator
Demonstration circuit 2131A is a current mode DC/DC
step-down Silent Switcher
®
buck regulator featuring the
LT C
®
3623. The board operates from an input range of 4V
to 15V, and provides ±5A of output current. The output
voltage of the demonstration board can be set from 0V to
VIN – 0.5V. It operates at 1MHz and may be synchronized
to an external clock. A soft-start feature controls output
voltage slew rate at start-up, reducing current surge and
voltage overshoot. A power good output and current
monitor signal are provided. Discontinuous conduction
mode can be selected with a jumper. The demonstration
board has options for cable drop compensation, negative
output voltage and input voltage regulation.
L, LT, LTC, LTM, Linear Technology, the Linear logo and Silent Switcher are registered
trademarks of Linear Technology Corporation. All other trademarks are the property of their
respective owners.
PERFORMANCE SUMMARY
This board is suitable for a wide range of battery-powered,
point-of-load, DDR memory, Thermo Electric Cooler (TEC)
systems and other applications. The LTC3623 is available
in a low profile, 24-pin QFN package. For other output
requirements, see the LTC3623 data sheet.
Design files for this circuit board are available at
http://www.linear.com/demo/DC2131A
Specifications are at TA= 25°C
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
VIN Input Supply Range 4 15 V
VOUT Output Voltage Jumper Selectable 1 5 V
IOUT Output Current Range, Continuous 200LFM 0 5 A
fSW Switching (Clock) Frequency 1 MHz
VOUT_P-P Output Ripple VIN = 12V, VOUT = 5V, IOUT = 5A (20MHz BW) <25 mVP–P
IREG Output Regulation VIN: 4V to 15V, AOUT: 0A to 5A, VOUT = 1V
VIN: 4V to 15V, AOUT: 0A to 5A, VOUT = 1.5V
VIN: 4V to 15V, AOUT: 0A to 5A, VOUT = 2.5V
VIN: 4.7V to 15V, AOUT: 0A to 5A, VOUT = 3.3V
VIN: 6.5V to 15V, AOUT: 0A to 5A, VOUT = 5V
±2
±2
±2
±2
±2
%
%
%
%
%

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dc2131afb
DEMO MANUAL DC2131A
QUICK START PROCEDURE
Demonstration circuit 2131A is easy to set up to evalu-
ate the performance of the LTC3623. Refer to Figure 1
for proper measurement equipment setup and follow the
procedure below:
NOTE:When measuring theoutput voltage ripple,care must
be taken to avoid a long ground lead on the oscilloscope
probe. Measure the output voltage ripple by touching the
probe tip and ground ring directly across the last output
capacitor as shown in Figure 1.
1. Using an input power supply that is capable of 4V to
15V, set the voltage to 12V. Then turn off the supply.
2. Withpoweroff,connectthesupplyto the input terminals
+VIN and –VIN.
a. If efficiency measurements are desired, an ammeter
capable of measuring 5A DC or a resistor shunt can be
put in series with the input supply in order to measure
the DC1722A’s input current.
b. A Voltmeter with a capability of measuring at least 15V
can be placed across the input terminals in order to get
an accurate input voltage measurement.
3. Turn on the power at the input.
NOTE: Make sure that the input voltage never
exceeds 15V.
4. Check for the proper output voltage which is set using
a jumper. Setting the jumper to the OPT position will
set the output voltage to 5V.
5. Once the proper output voltage is established, connect
a variable load capable of sinking 5A at 5V to the output
terminals +VOUT and –VOUT. Set the current for 0A.
a. If efficiency measurements are desired, an ammeter
or a resistor shunt that is capable of handling 5A DC
can be put in series with the output load in order to
measure the DC3623A’s output current.
b. A Voltmeter with a capability of measuring at least 5V
can be placed across the output terminals in order to
get an accurate output voltage measurement.
NOTE: If there is no output, temporarily disconnect the
load to make sure that the load is not set too high.
6. Adjust the load and/or input within the operating range
and observe the output voltage regulation, ripple volt-
age, efficiency and other desired parameters.

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dc2131afb
DEMO MANUAL DC2131A
QUICK START PROCEDURE
Figure 1. Proper Measurement Equipment Setup

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dc2131afb
DEMO MANUAL DC2131A
QUICK START PROCEDURE
Figure 2. 12VIN DCM Efficiency
Figure 3. Output Ripple at 15VIN, 5VOUT and 5AOUT (20mV, 500ns/DIV, 20MHz Bandwidth)
LOAD CURRENT (A)
0.01 1
10
0.1
EFFICIENCY (%)
95
90
80
70
85
75
65
60
dc2131a F02
2.5VOUT
3.3VOUT
5VOUT

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dc2131afb
DEMO MANUAL DC2131A
QUICK START PROCEDURE
Figure 4. Transient Response Waveform at 12VIN, 5VOUT and 2.5 – 5 – 2.5AOUT (2A, 100mV, 10µs/DIV, 20MHz Bandwidth)
Figure 5. Thermal at 12VIN, 3.3VOUT and 5AOUT, 0LFM

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dc2131afb
DEMO MANUAL DC2131A
ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER
Required Circuit Components
1 2 CIN1, CIN2 CAP., 2.2µF, X5R, 25V, 10%, 0402 MURATA., GRM155R61E225KE11
2 1 CIN3 CAP., 10µF, X5R, 25V, 10%, 1206 AVX., 12063D106KAT2A
3 1 CIN4 CAP., POSCAP, 22µF, 20V, B2 SIZE, TQC SERIES PANASONIC, 20TQC22MYFB
4 1 COUT1 CAP., 100µF, X5R, 10V, 20%, 1210 MURATA, GRM32ER61A107ME20L
5 2 C1, C3 CAP., 0.01µF, X5R, 25V, 10%, 0603 AVX., 06033D103KAT2A
6 2 C4, C5 CAP., 0.1µF, X7R, 25V, 10%, 0603 AVX, 06033C104KAT2A
7 1 C6 CAP., 4.7µF, X5R, 10V, 0603 AVX, 0603ZD475KAT2A
8 1 C7 CAP., 1nF, C0G, 25V, 1%, 0603 AVX, 06033A102FAT2A
9 1 C8 CAP., C0G, 100pF, 25V, 5%, 0603 AVX, 06033A101JAT2A
10 1 L1 IND., PWR 1µH, 20% XAL60XX SERIES COILCRAFT, XAL6030-102MEB
11 1 R1 RES., 24.9k, 1/10W, 1%, 0603 VISHAY, CRCW060324K0FKEA
12 1 R2 RES., 43k, 1/10W, 1%, 0603 VISHAY, CRCW060343K0FKEA
13 1 R3 RES., 100k, 1/10W, 1%, 0603 VISHAY, CRCW0603100KFKEA
14 1 R4 RES., 196k, 1/10W, 1%, 0603 VISHAY, CRCW0603200KFKEA
15 1 R7 RES., 10k, 1/10W, 1%, 0603 VISHAY, CRCW060310K0FKEA
16 1 R8 RES., 1M, 1/10W, 5%, 0603 VISHAY, CRCW06031M00JNEA
17 1 R12 RES., 1Ω, 1/10W, 5%, 0603 VISHAY, CRCW06031R00JNEA
18 1 R15 RES., 33.2k, 1/10W, 1%, 0603 VISHAY, CRCW060333K2FKEA
19 1 R16 RES., 5.49k, 1/10W, 1%, 0603 VISHAY, CRCW06035K49FKEA
20 2 R17, R19 RES., 100k, 1/10W, 5%, 0603 VISHAY, CRCW0603100KJNEA
21 1 U1 I.C., 15V, 5A MONOLITHIC SYNCHRONOUS BUCK CONV LINEAR TECH., LTC3623EUDD#PBF
Additional Demo Board Circuit Components
22 0 COUT2 CAP, OPTION 1210 OPTION
23 0 COUT3, COUT4 CAP, OPTION 7343 OPTION
24 0 C9, C10, C11 CAP, OPTION 0603 OPTION
25 0 C12 CAP, OPTION 1206 OPTION
26 0 D7 DIODE, OPTION OPTION
27 0 R5, R10, R11, R13, R14, R18,
R20, R21, R24, R25
RES, OPTION 0603 OPTION
28 4 R6, R9, R22, R23 RES., 0Ω, 1/10W, 0603 VISHAY, CRCW06030000Z0EA
Hardware: For Demo Board Only
29 7 E1, E2, E3, E5, E7, E8, E9 TEST POINT, TURRET, 0.094" MTG. HOLE MILL-MAX, 2501-2-00-80-00-00-07
30 6 JP1, JP2, JP3, JP4, JP5, JP8 CONN., HEADER, 1X2, 2mm SULLINS, NRPN021PAEN-RC
31 1 JP6 CONN., HEADER, 2X3, 2mm SULLINS, NRPN032PAEN-RC
32 1 JP7 CONN., HEADER, 1X3, 2mm SULLINS, NRPN031PAEN-RC
33 4 XJP1, XJP3, XJP4, XJP5 SHUNT, 2mm SAMTEC, 2SN-BK-G
34 4 (STAND-OFF) STAND-OFF, NYLON 0.50" TALL KEYSTONE, 8833(SNAP ON)
PARTS LIST

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dc2131afb
DEMO MANUAL DC2131A
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
5
5
4
4
3
3
2
2
1
1
D
D
C
C
B
B
A
A
-PRODUCTION
HZ
TIM K.3 5-23-16
10V
10V
10V
ALL RESISTORS AND CAPACITORS ARE IN 0603. NOTE: UNLESS OTHERWISE SPECIFIED
25V
DIS
ISET
GSNS
VOUT
ITH
GSNS
PGFB INTVCC
GSNS GSNS
DIR
PGFB
VIN
VIN
VIN
SW
INTVCC
INTVCC DIR
SW
INTVCC
VOUT
INTVCC VOUT
VIN
REVISION HISTORY
DESCRIPTION D AT E
APPROVED
ECO REV
REVISION HISTORY
DESCRIPTION D AT E
APPROVED
ECO REV
REVISION HISTORY
DESCRIPTION D AT E
APPROVED
ECO REV
SIZE DATE:
IC NO. REV.
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
3
Thursday, September 22, 2016
11
15VIN, +/- 5A MONOLITHIC BUCK REGULATOR
HZ
TIM K.
N/A
LTC3623EUDD
DEMO CIRCUIT 2131A
SIZE DATE:
IC NO. REV.
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
3
Thursday, September 22, 2016
11
15VIN, +/- 5A MONOLITHIC BUCK REGULATOR
HZ
TIM K.
N/A
LTC3623EUDD
DEMO CIRCUIT 2131A
SIZE DATE:
IC NO. REV.
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
3
Thursday, September 22, 2016
11
15VIN, +/- 5A MONOLITHIC BUCK REGULATOR
HZ
TIM K.
N/A
LTC3623EUDD
DEMO CIRCUIT 2131A
C3
0.01uF
R7 10K
R10
(OPT)
R17 100K
R9 0 Ohm
C6 4.7uF
JP8
PGFB
L1
1uH
JP6
CCM
DCM SYNC
MODE/SYNC
1 3
2 4 65
R25 OPT
R18 (OPT)
COUT1 100uF
10V
1210
R243K1%
R24 OPT
E3
IMON
E5
PGOOD
C7
1nF
R3100K1%
JP1 1.0V
U1 LTC3623EUDD
ISET
1
PGOOD
2
RUN
3
GSNS
4
PVIN
5
SW
6
NC
7
MODE/SYNC
8
PGND
9
PGND
10
PGND
11
PGND
12
VOUT 13
NC 14
SW 15
PVIN 16 SVIN 17
BOOST 18
INTVCC 19
PGFB 20
IMON
21
DIR
22
RT
23
ITH
24
25
PGND
C10 OPT
R14
(OPT)
JP4 3.3V
R124.9K1%
R20 (OPT)
R19 100K
R12 1
R13
(OPT)
JP3 2.5V
C5 0.1uF
R21 OPT
E1
VIN
4V to 15V
C4
0.1uF
R4196K1%
E8
VOUT
2.5V / 5A
CIN2 2.2uF 25V 0402
JP2 1.5V
R8 1M
C11 OPT
E2
GND
C12 OPT
CIN3 10uF 25V 1206
COUT2
OPT
1210
R5(OPT) JP5 5V
R22 0
E9
GND
+
CIN4 22uF 20V 20TQC22MYFB
R23 0
R6
0 Ohm
C8
100pF
JP7
ON
OFF
RUN
1 3 2
E7
SYNC
+
COUT4
(OPT)
D7
OPT
CIN1 2.2uF 25V 0402
R16 5.49K
C9 OPT
+
COUT3
(OPT)
R11
(OPT)
C1
0.01uF
R15
33.2K

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dc2131afb
DEMO MANUAL DC2131A
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
[phone] ●FAX: [phone] ●www.linear.com
© LINEAR TECHNOLOGY CORPORATION 2016
LT 1116 REV A • 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 application
engineer.
Mailing Address:
Linear Technology
1630 McCarthy Blvd.
Milpitas, CA 95035
Copyright © 2004, Linear Technology Corporation

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