Analog Devices Linear Technology DC2268A-C Quick setup guide

1
dc2268acf
DEMO MANUAL
DC2268A-C
Description
LTM4628
Dual 8A or Single 16A
μModule Regulator
Demonstration circuit 2268A-C is a high efficiency, high
density, dual 8A, switch mode step-down power supply
on a compact 1.5˝×1.2˝ PCB. It features the LTM
®
4628
μModule
®
regulator. The input voltage is from 5.5V to
16V. The output voltage is programmable from 0.6V to
5.5V. DC2268A-C can deliver up to 8A maximum in each
channel. As explained in the data sheet, output current
derating is necessary for certain VIN, VOUT and thermal
conditions. The board operates in continuous conduc-
tion mode in heavy load conditions. For high efficiency
at low load currents, the resistor jumper (R1/R2) selects
pulse-skipping mode for noise sensitive applications or
Burst Mode
®
operation in less noise sensitive applica-
tions. Two outputs can be connected in parallel for a single
16A output solution with optional jumper resistors. The
board allows the user to program how its output ramps
L, LT, LTC, LTM, Linear Technology, Burst Mode, µModule and the Linear logo are registered
trademarks of Analog Devices, Inc. All other trademarks are the property of their respective
owners.
BoarD photo
up and down through the TRACK/SS pin. Remote output
voltage sensing is available for improved output voltage
regulation at the load point. An optional input inductor L1
reduces the EMI noise for noise sensitive applications.
DC2268A can be easily inserted to an edge connector for
testing and debugging. These features and the availability
of the LTM4628 in a compact 15mm x 15mm x 4.41mm
LGA package make it ideal for use in many high-density
point-of-load regulation applications. The LTM4628 data
sheet must be read in conjunction with this demo manual
for working on or modifying the demo circuit DC2268A-C.
Design files for this circuit board are available at
http://www.linear.com/demo/DC2268A-C
Figure 1. LTM4628/DC2268A-C Demo Board

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dc2268acf
DEMO MANUAL
DC2268A-C
Quick start proceDure
Demonstration circuit DC2268A-C is easy to set up
to evaluate the performance of the LTM4628. It can
be easily inserted to an edge connector (SAMTEC
MEC2-20-01-L-DV--TR) for testing and debugging. Please
refer to Figure2 for proper measurement setup and follow
the procedure below:
1. Pull up the RUN1 (J1 pin 22) and RUN2 (J1 pin 24)
between 1.4V and 5V or leave them floating.
2. With power off, connect the input power supply, load
and meters as shown in Figure2. Preset the load to 0A
and VIN supply to 12V.
3. Turn on the power supply at the input. The output volt-
age in channel 1 should be 1.0V± 1.5% (0.985V be
~1.015V) and the output voltage in channel 2 should
be 1.5V ±1.5% (1.4775V to ~1.5225V),
4. Oncetheproperoutputvoltageisestablished,adjustthe
load within the operating range and observe the output
voltage regulation, output voltage ripple, efficiency and
other parameters. Output ripple should be measured
at CO3 and CO4.
5. (Optional) LTM4628 can be synchronized to an external
clocksignal.RemoveR2 and applyaclocksignal (0~5V,
square wave) to MODE-PLLIN pin.
6. (Optional) LTM4628 can be configured for a 2-phase
single output at up to 16A on DC2268A-C. Install 0Ω
resistors on R26, R27, R28, R29, R32, and remove
R14, R18 and R30. Output voltage is set by R7 based
on the equation: VOUT = 0.6V (1 + 60.4K/R7).
performance summary
Specifications are at TA= 25°C
PARAMETER CONDITIONS VALUE
Input Voltage Range 5.5V to ~16V
Output Voltage VOUT1 VIN = 4.5V to ~16V, IOUT1 = 0V to ~8A 1.0V ± 1.5%
Output Voltage VOUT2 VIN = 4.5V to ~16V, IOUT2 = 0V to ~8A 1.5V ± 1.5%
Per-channel Maximum Continuous Output Current Derating is necessary for certain VIN, VOUT and thermal conditions. 8A (per channel)
Default Operating Frequency 500kHz
Resistor Programmable Frequency Range 250kHz to 780kHz
External Clock Sync. Frequency Range 400kHz to 780kHz
Efficiency of Channel 1 VIN = 12V, VOUT2 = 1.0V, IOUT2 = 8A, fSW = 500kHz 80.7% See Figure 3
Efficiency of Channel 2 VIN = 12V, VOUT1 = 1.5V, IOUT1 = 8A, fSW = 500kHz 84.6% See Figure 4
Load Transient of Channel 1 VIN = 12V, VOUT2 = 1.0V, ISTEP = 4A to 6A VOPP = 56mV See Figure 5
Load Transient of Channel 2 VIN = 12V, VOUT1 = 1.5V, ISTEP = 4A to 6A VOPP = 67mV See Figure 6

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dc2268acf
DEMO MANUAL
DC2268A-C
Quick start proceDure
Figure 2. Test Setup of DC2268A-C
Table 1. DC2268A Demo Circuit
DEMO BOARD NUMBER µModule REGULATOR ON THE BOARD OUTPUT CURRENT
DC2268A-A LTM4620 13A,13A
DC2268A-B LTM4620A 13A,13A
DC2268A-C LTM4628 8A, 8A
DC2268A-D LTM4630 18A, 18A
DC2268A-E LTM4630-1 18A, 18A
DC2268A-F LTM4630A 18A, 18A
DC2268A-G LTM4631 10A, 10A
DC2268A-H LTM4650-1 25A, 25A
DC2268A-I LTM4650A-1 25A, 25A
DC2268AC F02
LOAD1
0A ~ 8A
+
–
+
–
VOUT1
LOAD2
0A ~ 8A
+
–
+
–
VOUT2
+
–
+
–
+
–
VIN
5.5V to 16V

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dc2268acf
DEMO MANUAL
DC2268A-C
Quick start proceDure
Figure 3. Measured Efficiency on Channel 1
(VOUT1=1.0V, fSW=500kHz, Channel 2 Disabled)
Figure 4. Measured Efficiency on Channel 2
(VOUT2=1.5V, fSW=500kHz, Channel 1 Disabled)
Figure 5. Measured Channel 1, 4A to 6A Load Transient (VIN=12V, VOUT1=1.0V)
OUTPUT LOAD CURRENT (A)
EFFICIENCY (%)
DC2268AC F03
60
65
70
75
80
85
90
95
100
0 8642
VIN = 5V
VIN = 12V
OUTPUT LOAD CURRENT (A)
EFFICIENCY (%)
DC2268AC F04
60
65
70
75
80
85
90
95
100
0
8
642
VIN = 5V
VIN = 12V
1.0V OUTPUT (20MHz BW) [20mV/DIV]
4A TO 6A LOAD STEP

5
dc2268acf
DEMO MANUAL
DC2268A-C
Quick start proceDure
Figure 6. Measured Channel 2, 4A to 6A Load Transient (VIN=12V, VOUT2=1.5V)
Figure 7. Thermal Performance at VIN=12V, VOUT1=1.0V/8A, VOUT2=1.5V/8A, fSW=500kHz, TA=23°C, 200LFM Airflow
1.5V OUTPUT (20MHz BW) [20mV/DIV]
4A TO 6A LOAD STEP

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dc2268acf
DEMO MANUAL
DC2268A-C
parts List
ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER
Required Circuit Components
1 6 CIN1, CIN2, CIN3, CIN4, CIN5, CIN6 CAP, 1210 22µF 10% 25V X5R AVX, 12103D226KAT2A
2 2 CO1, CO5 CAP, 7343 330µF 20% 6.3V POSCAP PANASONIC, 6TPF330M9L
3 4 CO2, CO3, CO4, CO6 CAP, 1210 100µF 10% 6.3V X5R AVX, 12106D107KAT2A
4 1 C6 CAP, 0603 4.7µF 20% 6.3V X5R AVX, 06036D475MAT2A
5 1 C7 CAP, 0603 47pF 5% 50V C0G / NP0 AVX, 06035A470JAT2A
6 2 C8, C14 CAP, 0603 0.1µF 10% 25V X7R AVX, 06033C104KAT2A
7 1 C15 CAP, 0603 33pF 5% 50V C0G AVX, 06035A330JAT2A
8 2 C16, C17 CAP, 0603 10µF 20% 25V X5R TDK, C1608X5R1E106M080AC
9 2 C18, C20 CAP, 0603 22µF 20% 6.3V X5R TDK, C1608X5R0J226M080AC
10 1 L1 IND, 1.0µH COILCCRAFT, XAL5030-102MEC
11 2 R2, R22 RES, 0603 0Ω JUMPER VISHAY, CRCW06030000Z0EA
12 3 R3, R5, R14 RES, 0603 100Ω 5% 0.1W VISHAY, CRCW0603100RJNEA
13 1 R4 RES, 0603 121k 1% 0.1W VISHAY, CRCW0603121KFKEA
14 2 R6, R17 RES, 0603 10k 5% 0.1W VISHAY, CRCW060310K0JNEA
15 1 R7 RES, 0603 13.3k 1% 0.1W VISHAY, CRCW060313K3FKEA
16 1 R9 RES, 0603 0Ω VISHAY, CRCW06030000Z0EA
17 1 R15 RES, 0603 191k 1% 0.1W VISHAY, CRCW0603191KFKEA
18 1 R18 RES, 0603 8.25k 1% 0.1W VISHAY, CRCW06038K25FKEA
19 3 R24, R25, R30 RES, 0603 10Ω 5% 0.1W VISHAY, CRCW060310R0JNEA
20 1 U1 IC, VOLTAGE REGULATOR LGA LINEAR TECH., LTM4628EV#PBF
Additional Demo Board Circuit Components
1 0 C1, C2, C3, C4, C5, C9, C10, C11, C12,
C13
CAP, 0603 OPTION OPTION
2 0 R1, R8, R10, R11, R12, R13, R16, R19,
R20, R21, R23, R26, R27, R28, R29
RES, 0603 OPTION OPTION
3 0 R31, R32 RES, 2512 OPTION OPTION
Hardware: For Demo Board Only
1 1 J1 CONN., CARD EDGE 1.6mm SAMTEC MEC2-20-01-L-DV--TR

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dc2268acf
DEMO MANUAL
DC2268A-C
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

OPTIONAL JUMPER FOR
1 OUTPUT CONFIGURATION
1.0V
1.5V

VERSION MODULE
-A LTM4620
-B LTM4620A
-C LTM4628 -D LTM4630
-E LTM4630-1
-F LTM4630A
[1]
-G LTM4631 -H LTM4650-1 - I LTM4650A-1
PGOOD1
RUN1
VOS1+
PGOOD2
COMP1
TRACK1
VFB1
VFB1
VFB2 COMP2 RUN2
VFB2
VFB1
VOS1-_R VOS1+_R VOS2+_R VOUT1 VOUT2 VOUT2
VOUT1 RUN2 RUN1
VOS1-_R
VOS1+_R
VOS2+_R
VOS2+
TRACK2
VOS1-
VOS1+
VIN2
INTVCC
INTVCC
VOUT1
VOS1+
VOS1-
INTVCC
VOUT2
EXTVCC
VIN1
VIN2
VOS2+
INTVCC VIN2
INTVCC
VIN1 VIN1
VOUT1 VOUT2
VOUT1
VOUT2
RUN1 RUN2
TRACK1 TRACK2
VFB1 VFB2
COMP1 COMP2
SIZE DATE:
IC NO. REV.
SHEET OF
TITLE:
APPROVALS
PCB DES.
APP ENG.
TECHNOLOGY Fax: [phone]
Milpitas, CA 95035 Phone: [phone]
1630 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
DEMO CIRCUIT 2268A
Wednesday, April 05, 2017
11
HIGH EFFICIENCY, STEP-DOWN, MODULE
N/A
LTM4620/LTM4620A/LTM4628/
` \
Simon. T
REGULATOR
C:\PROJECTS\LTM4628\DC2268A-C\DC2268A-2.DSN LTM4630/LTM4630-1/LTM4631
SIZE DATE:
IC NO. REV.
SHEET OF
TITLE:
APPROVALS
PCB DES.
APP ENG.
TECHNOLOGY Fax: [phone]
Milpitas, CA 95035 Phone: [phone]
1630 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
DEMO CIRCUIT 2268A
Wednesday, April 05, 2017
11
HIGH EFFICIENCY, STEP-DOWN, MODULE
N/A
LTM4620/LTM4620A/LTM4628/
` \
Simon. T
REGULATOR
C:\PROJECTS\LTM4628\DC2268A-C\DC2268A-2.DSN LTM4630/LTM4630-1/LTM4631
SIZE DATE:
IC NO. REV.
SHEET OF
TITLE:
APPROVALS
PCB DES.
APP ENG.
TECHNOLOGY Fax: [phone]
Milpitas, CA 95035 Phone: [phone]
1630 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
DEMO CIRCUIT 2268A
Wednesday, April 05, 2017
11
HIGH EFFICIENCY, STEP-DOWN, MODULE
N/A
LTM4620/LTM4620A/LTM4628/
` \
Simon. T
REGULATOR
C:\PROJECTS\LTM4628\DC2268A-C\DC2268A-2.DSN LTM4630/LTM4630-1/LTM4631
C1 OPT
CIN1
22uF 25V
1210
R1
OPT
R11
OPT
CIN2
22uF 25V
1210
+
CO1
470uF 2.5V
7343
R31 OPT
C5 1000pF
R23
OPT
P2
R32
OPT
CIN6
22uF 25V
1210
C9
OPT
C7 OPT
R21
OPT
R12 OPT
R15
121K 1%
CO6
100uF 6.3V 1210
CO2
100uF 6.3V 1210
U1 [1]
VOUT1
A1
VOUT1
A2
VOUT1
A3
VOUT1
A4
VOUT1
A5
VOUT1
B1
VOUT1
B2
VOUT1
B3
VOUT1
B4
VOUT1
B5
VOUT1
C1
VOUT1
C2
VOUT1
C3
VOUT1
C4
VFB1
D5
SW1
G2
PGOOD1
G9
COMP1
E6
RUN1
F5
TRACK1
E5
VOUTS1
C5
VOUT2
A8
VOUT2
A9
VOUT2
A10
VOUT2
A11
VOUT2
A12
VOUT2
B8
VOUT2
B9
VOUT2
B10
VOUT2
B11
VOUT2
B12
VOUT2
C9
VOUT2
C10
VOUT2
C11
VOUT2
C12
VFB2
D7
SW2
G11
PGOOD2
G8
COMP2
E7
RUN2
F9
TRACK2
D8
VOUTS2
C8
VIN
M2
VIN
M3
VIN
M4
VIN
M5
VIN
M6
VIN
M7
VIN
M8
VIN
M9
VIN
M10
VIN
M11
VIN
L2
VIN
L3
VIN
L4
VIN
L5
VIN
L6
VIN
L7
VIN
L8
VIN
L9
VIN
L10
VIN
L11
VIN
K2
VIN
K3
VIN
K4
VIN
K9
VIN
K10
VIN
K11
VIN
J2
VIN
J3
VIN
J4
VIN
J9
VIN
J10
VIN
J11
GND
A6
GND
A7
GND
B6
GND
B7
GND
D1
GND
D2
GND
D3
GND
D4
GND
D9
GND
D10
GND
D11
GND
D12
GND
E1
GND
E2
GND
E3
GND
E4
GND
E10
GND
E11
GND
E12
GND
F1
GND
F2
GND
F3
GND
F10
GND
F11
GND
F12
GND
G1
GND
G3
GND
G10
GND
G12
GND
H1
GND
H2
GND
H3
GND
H4
GND
H5
GND
H6
GND
H7
GND
H9
GND
H10
GND
H11
GND
H12
GND
M12
GND
M1
GND
L12
GND
J1
GND
J5
GND
J8
GND
J12
GND
K1
GND
K5
GND
K6
GND
K7
GND
K8
GND
K12
GND
L1
SGND
C7
SGND
D6
SGND
F6
SGND
F7
SGND
G6
SGND
G7
FSET
C6
PHASMD
G4
DIFFP
E8
DIFFN
E9
CLKOUT
G5
MODE-PLLIN
F4
TEMP
J6
INTVCC
H8
EXTVCC
J7
DIFFOUT
F8
R24 10
CIN4
22uF 25V
1210
C11 OPT
C4
150pF
R16
14k 1%
R10
7.87k
1%
R14
100
R3
100
J1
VIN
1
VIN
2
VIN
3
VIN
4
GND
5
GND
6
GND
7
GND
8
GND
9
GND
10
GND
11
GND
12
GND
13
GND
14
N/A
15
N/A
16
GND
17
GND
18
VOS1+
19
GND
20
VOS1-
21
RUN1
22
VOS2+
23
RUN2
24
VOUT1
25
VOUT1
26
VOUT1
27
VOUT1
28
VOUT1
29
VOUT1
30
VOUT1
31
VOUT1
32
VOUT2
33
VOUT2
34
VOUT2
35
VOUT2
36
VOUT2
37
VOUT2
38
VOUT2
39
VOUT2
40
R20 OPT
R22
0
P3
CIN3
22uF 25V
1210
R13 OPT
R17
10K
+
CO5
470uF 2.5V
R7 90.9K 1%
R8
OPT
C2 OPT
L1 1uH
C16
10uF
25V R2
0
R6
10K
C15 OPT
C18
22uF
CO4
100uF 6.3V 1210
C3 OPT
C17
10uF
25V CO3
100uF 6.3V 1210
CIN5
22uF 25V
1210
P1
R25 10
R26
OPT
R4
121K
1%
C8 0.1uF
C12
1000pF
C13
150pF
R5
100
C20
22uF
R9 0
C10 OPT
4.7uF
C6
6.3V
C14 0.1uF
R30 10
R28
OPT
R19
OPT
R18
40.2K 1%
R27
OPT
R29
OPT

8
dc2268acf
DEMO MANUAL
DC2268A-C
 LINEAR TECHNOLOGY CORPORATION 2017
LT 0517 • 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