Linear Technology DC1700A Quick setup guide

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dc1700af
DEMO MANUAL DC1700A
DESCRIPTION
LTC3613EWKH
Fast, High Efficiency
Step-Down Regulator
Demonstration circuit 1700A is a fast, high efficiency
synchronous buck DC/DC converter with 4.5V to 24V
input range. It can supply 15A maximum load current at
1.5V output. The demo board features the LTC
®
3613EWKH
regulator. No external MOSFETs are required. The con-
trolled on-time constant frequency valley current mode
architecture allows for both fast transient response and
constant frequency switching in steady-state operation.
Differential output voltage sensing along with a precision
internal reference combine to offer an accurate output
regulation. The LTC3613 is ideal for applications such
as distributed power systems, servers and point-of-load
converters. The LTC3613EWKH is in a 7mm ×9mm 54-pin
QFN package.
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
The light load operation mode of the converter is de-
termined with the MODE/PLLIN pin. Use JP2 jumper to
select discontinuous mode (DCM) or forced continuous
mode (CCM) operation. Switching frequency is pre-set
at about 350kHz. This frequency can be modified from
200kHz to 1MHz by changing the value of a resistor (R18).
The converter can also be externally synchronized from
200kHz to 1MHz through the MODE/PLLIN pin (PLLIN
terminal on the board). To shut down the converter, one
simple way is to force the RUN pin below 1.1V (JP1: OFF).
The power good output (PGOOD terminal) is low when the
output voltage is outside of the ±7.5% regulation window.
Design files for this circuit board are available at
http://www.linear.com/demo
(TA= 25°C)
PARAMETER CONDITIONS VALUE
Input Voltage Range 4.5V to 24V
Output Voltage, VOUT VIN = 4.5V to 24V, IOUT = 0A to 15A 1.5V ±2%
Maximum Output Current, IOUT VIN = 4.5V to 24V, VOUT = 1.5V 15A
Typical Output Ripple VIN = 12V, IOUT = 15A (20MHz BW) 40mVP–P
Typical Efficiency VIN = 12V, VOUT = 1.5V, IOUT = 15A 87.5%
Typical Switching Frequency 350kHz

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DEMO MANUAL DC1700A
QUICK START PROCEDURE
Figure 1. Proper Measurement Equipment Setup
Figure 2. Measuring Output Voltage Ripple
Demonstration circuit 1700A is easy to set up to evaluate
the performance of the LTC3613. 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
(4.5V to 24V) and GND (input return).
2. Connect the 1.5V 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 1.5V ±2%.
5. Once the proper output voltages are established, ad-
just the loads within the operating range and observe
the output voltage regulation, ripple voltage and other
parameters.
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.
+–
VOUT GND
COUT

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DEMO MANUAL DC1700A
QUICK START PROCEDURE
Figure 3. Efficiency vs Load Current (VIN = 12V, VO= 1.5V, CCM)
LOAD CURRENT (A)
0
82
EFFICIENCY (%)
90
89
88
87
86
85
84
83
91
51015

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DEMO MANUAL DC1700A
PARTS LIST
ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER
Required Circuit Components
1 2 CIN1, CIN2 CAP, 1210 10μF 10% 16V X5R AVX, 1210YD106KAT
2 1 CIN4 CAP, 82μF, 25V, Sanyo SANYO, 25SVPD82M
3 2 COUT1, COUT2 CAP, 1206 100μF 20% 6.3V X5R MURATA, GRM31CR60J107ME39L
4 2 COUT3, COUT4 CAP, 7343 330μF 20% 2.5V POSCAP SANYO 2R5TPE330M9
5 2 C1, C8 CAP, 0603 0.1μF 10% 25V X7R TDK C1608X7R1E104K
6 1 C2 CAP, 0603 1000pF 10% 50V X7R AVX, 06035C102KAT
7 2 C3, C5 CAP, 0805 4.7μF 10% 16V X5R TDK C2012X5R1C475K
8 1 C6 CAP, 0603 47pF 10% 25V NPO AVX, 06033A470KAT2A
9 1 C7 CAP, 0603 0.01μF 10% 50V X7R AVX, 06035C103KAT
10 1 C9 CAP, 0603 270pF 10% 25V NPO AVX, 06033A271KAT2A
11 1 C10 CAP, 0603 1μF 10% 25V X5R AVX, 06033D105KAT
12 1 D1 DIODE,CMDSH-3 SOD323 CENTRAL CMDSH-3
13 1 L1 IND., 0.47μH, FP1109 series COILTRONICS, FP1109-R47-R
14 1 Q5 XSTR, MOSFET, DPAK-TO252AA VISHAY SUD50N03-12P-E3
15 1 RS1 RES, 2010 0.0015Ω 1% 1/2W VISHAY WSL20101L500FEA
16 1 R1 RES, 0603 100k 1% 1/10W VISHAY CRCW0603100KFKEA
17 3 R2, R12, R17 RES, 0603 0Ω JUMPER VISHAY CRCW06030000Z0EA
18 2 R4, R5 RES, 0603 10Ω 1% 1/10W VISHAY CRCW060310R0FKEA
19 2 R6, R8 RES, 0603 100Ω 1% 1/10W PANASONIC, ERJ-3EKF1000V
20 1 R10 RES, 0603 90.9k 1% 1/10W PANASONIC, ERJ-3EKF9092V
21 1 R11 RES, 0603 60.4k 1% 1/10W VISHAY, CRCW060360K4FKEA
22 1 R13 RES, 0603 2.2Ω 1% 1/10W NIC, NRC06F2R20TRF
23 1 R15 RES, 0603 21k 1% 1/10W VISHAY, CRCW060321K0FKEA
24 1 R18 RES, 0603 115k 1% 1/10W VISHAY, CRCW0603115KFKEA
25 2 R20, R23 RES, 0603 10k 1% 1/10W NIC, NRC06F1002TRF
25 1 R22 RES, 2010 0.01Ω 1% 1/2W VISHAY WSL2010R0100FEA
27 1 U1 LTC3613EWKH QFN-56-7X9
Additional Demo Board Circuit Components
28 1 CIN3 OPT, 1210
29 2 COUT5, COUT6 OPT
30 3 C4, R9, R16 OPT
31 1 R3 OPT
32 4 R7, R14, R19, R21 OPT
Demo Board Only
33 12 E1, E2, E3, E4, E5, E6, E7, E8, TURRET MILL-MAX 2501-2-00-80-00-00-07-0
34 E9, E10, E11, E12
35 2 JP1, JP2 HEADER, 3PIN, 2mm SAMTEC TMM-103-02-L-S
36 2 XJP1, XJP2 SHUNT, 2mm SAMTEC 2SN-BK-G
37 2 J1, J2 JACK, BANANA KEYSTONE 575-4
38 2 J3, J4 CONN, BNC, 5 PINS CONNEX 112404

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DEMO MANUAL DC1700A
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
1. WHEN DCR SENSING IS IMPLEMENTED, SHORT RS1 AND R9; DO NOT POPULATE R6 AND R8.
NOTES: UNLESS OTHERWISE SPECIFIED
1.5V / 15A
LOAD STEP
LOAD STEP CIRCUIT
5% DUTY CYCLE MAX
RUN FSW = 350kHz
CIRCUIT
ON
OFF
0
OPT
OPT
VOUT
CCM MODE DCM
2. ALL RESISTORS ARE IN 0603 ALL CAPACITORS ARE IN 0603
4.5V - 24V
SW
SW
S+
EXTVCC
VOUT
EXTVCC
VOUT
S+
S-
S-
INTVCC
VIN
INTVCC
VIN
INTVCC
INTVCC
INTVCC
VIN
INTVCC
REVISION HISTORY DESCRIPTION DATEAPPROVEDECO REV
CHARLIE Z.PRODUCTION3 08-23-11
__
REVISION HISTORY DESCRIPTION DATEAPPROVEDECO REV
CHARLIE Z.PRODUCTION3 08-23-11
__
REVISION HISTORY DESCRIPTION DATEAPPROVEDECO REV
CHARLIE Z.PRODUCTION3 08-23-11
__
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
Tuesday, August 23, 2011
11
FAST, HIGH EFFICIENCY STEP-DOWN REGULATOR
AK
CHARLIE Z.
N/A
LTC3613EWKH
DEMO CIRCUIT 1700A
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
Tuesday, August 23, 2011
11
FAST, HIGH EFFICIENCY STEP-DOWN REGULATOR
AK
CHARLIE Z.
N/A
LTC3613EWKH
DEMO CIRCUIT 1700A
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
Tuesday, August 23, 2011
11
FAST, HIGH EFFICIENCY STEP-DOWN REGULATOR
AK
CHARLIE Z.
N/A
LTC3613EWKH
DEMO CIRCUIT 1700A
R9R9
C6 47pFC6 47pF
E9
EXTVCC E9 EXTVCC
C10
1uF
C10
1uF
R3R3
CIN2 10uF 25V 1210 CIN2 10uF 25V 1210
R12
0
R12
0
J4J4
R23 10k R23 10k
CIN3 1210 OPT CIN3 1210 OPT
C1
0.1uF
16V
C1
0.1uF
16V
COUT2
100uF 6.3V 1206
COUT2
100uF 6.3V 1206
D1
CMDSH-3
D1
CMDSH-3
1 2
J3J3
R1 100K R1 100K
E3 VIN+ E3 VIN+
U1B
LTC3613EWKH
U1B
LTC3613EWKH
PVIN
2
PVIN
3
PVIN
4
PVIN
5
PVIN
6
PVIN
7
PVIN
8
PVIN
9
SGND
16
SGND
17
SGND
19
SGND
28
SGND
29 PGND 36
PGND 37 PGND 38 PGND 39 PGND 40 PGND 41 PGND 42 PGND 43 PGND 44
SW 45 SW 46 SW 47 SW 48 SW 49 SW 50 SW 51
NC 52
PVIN
53 PVIN 54 PVIN 55 PVIN 56
SGND
57
SW 59
PVIN
58
C4 OPT C4 OPT
R8 100 R8 100
E7
PULSE GEN
E7
PULSE GEN
R2
0
R2
0
R14 OPT R14 OPT R15 21KR15 21K
E2 VO_SNS- E2 VO_SNS-
C9
270pF
C9
270pF
E8 GND E8 GND
E1 VO_SNS+ E1 VO_SNS+
+
COUT3 330uF 7343 2.5V
+
COUT3 330uF 7343 2.5V
COUT5 1206 OPT COUT5 1206 OPT
CIN1 10uF 25V 1210 CIN1 10uF 25V 1210
E12
TRACK E12 TRACK
E4 VIN E4 VIN
R21 OPT R21 OPT
RS1
2010
0.0015
RS1
2010
0.0015
R17R17
C7 0.01uF C7 0.01uF
E5 GND E5 GND
Q5
SUD50N03-12P
Q5
SUD50N03-12P
3
1
2
R5 10 R5 10
E11
PGOOD E11 PGOOD
R13
2.2
R13
2.2
R22 0.01 2010 R22 0.01 2010
JP1JP1
1 3 2
R10 90.9K R10 90.9K
COUT6 1206 OPT COUT6 1206 OPT
JP2JP2
1 3 2
U1A
LTC3613EWKH
U1A
LTC3613EWKH
PGOOD
13
SNS+
14
SNS-
15
VOUT
18
VOSNS-
20
VOSNS+
21
TRACK/SS
22
ITH
23
VRNG
24
RT
25 RUN 26
EXTVCC 30
MODE/PLLIN 31
INTVCC 33
PGND 36
NC 27
SW 10
PVIN 1
BOOST 11
SVIN 32
SGND
12
INTVCC 34
SW 35
L1
0.47uH
FP1109-R47
L1
0.47uH
FP1109-R47
+
CIN4 82uF 25V SANYO 25SVPD82M
+
CIN4 82uF 25V SANYO 25SVPD82M
R11 60.4K R11 60.4K
E10
PLLIN E10 PLLIN
C8
0.1uF
50V
C8
0.1uF
50V
R6 100R6 100
J1
VOUT
J1
VOUT
+
COUT4 330uF 7343 2.5V
+
COUT4 330uF 7343 2.5V
COUT1
100uF 6.3V 1206
COUT1
100uF 6.3V 1206
C5
4.7uF
16V
0805
C5
4.7uF
16V
0805
C2
1000pF
C2
1000pF
E6 VIN- E6 VIN- J2 GND J2 GND
R7
OPT
R7
OPT
R16
OPT
R16
OPT
C3 4.7uF
16V 0805
C3 4.7uF
16V 0805
R4 10 R4 10
R18 115K R18 115K
R19 OPT R19 OPT
R20 10K R20 10K

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DEMO MANUAL DC1700A
LinearTechnology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
[phone] ●FAX: [phone] ●www.linear.com
© LINEAR TECHNOLOGY CORPORATION 2011
LT 1011 • 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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