Linear Technology DC2455A-B Quick setup guide

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dc2455abf
DEMO MANUAL DC2455A-B
Description
LTM4650EY-1
High Efficiency, PolyPhase 150A Step-Down
Power µModule
®
Regulator
3× LTM4650EY-1, 150A
DemonstrationCircuit2455A-BfeaturesPolyPhase
®
design
using the LT M
®
4650EY-1 (B-grade), the high efficiency,
high density, dual 25A, switch mode step-down power
module regulator. The input voltage is from 4.5V to 15V.
The output voltage is jumper selectable from 0.9V to 1.8V.
DC2455A-B can deliver nominal 150A output current. As
explained in the data sheet, output current de-rating is
necessary for certainVIN,VOUT, and thermalconditions.The
LTM4650-1 on DC2455A-B always operate in continuous
conduction mode. The switching frequency can be pro-
grammed through a resistor or can be synchronized to an
external clock signal. The board allows the user to program
how its output voltage ramps up and down through the L, LT, LTC, LTM, Linear Technology, the Linear logo, µModule, PolyPhase and TimerBlox are
registered trademarks of Linear Technology Corporation. All other trademarks are the property
of their respective owners.
TRACK pin. The output voltage is tightly regulated between
“VO+”and “VO–”through remote output voltage sensing
which improves output voltage regulation at heavy loads.
These features and the availability of the LTM4650EY-1
in a compact 16mm × 16mm × 5.01mm BGA package
make it ideal for use in many high-density point-of-load
regulation applications. The LTM4650-1 data sheet must
be read in conjunction with this demo manual for working
on or modifying the demo circuit DC2455A-B.
Design files for this circuit board are available at
http://www.linear.com/demo/DC2455A-B
Figure 1. 3× LTM4650-1, 150A PolyPhase LTM4650-1/DC2455A-B Demo Board

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dc2455abf
DEMO MANUAL DC2455A-B
Quick start proceDure
Demonstration circuit DC2455A-B is easy to set up to
evaluate the performance of PolyPhase operation of the
LTM4650EY-1. Due to the high input/output current, user
should select the proper input supply/load/cable which
can sustain the full load operation. It’s recommended to
pull load current from J2 and J4. The load current pulled
from J5 and J6 shouldn’t exceed 25A. Please refer to
Figure 2 for proper measurement setup and follow the
procedure below:
1. Place jumpers in the following positions for a typical
1.0VOUT application:
JP1 JP2 JP4~JP8
CLK RUN VOUT SELECT
INT OFF ON JP5 / 1.0V
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. Place JP2 to ON
position. The output voltage between “VO+”and “VO–”
should be 1.0V ± 1.5% (0.985V~1.015V).
4. Once the proper output voltage is established, adjust the
load within the operating range and observe the output
voltage regulation, output voltage ripple, efficiency
and other parameters. Output voltage ripple should be
measured at J11 with BNC cables. 50Ω termination
should be set on the oscilloscope or BNC cables.
5. (Optional) For optional load transient test, apply an
adjustable pulse signal between “IOSTEP CLK”and
“GND” test point. Pulse amplitude (3V~3.5V) sets the
load step currentamplitude. Theoutput transientcurrent
can be monitored at the BNC connector J12 (5mV/A).
The pulse signal should be very small duty cycle (<
10%) to limit the thermal stress on the transient load
circuit.
6. (Optional) LTM4650-1 can be synchronized to an exter-
nal clock signal. Place the JP1 jumper on EXT and apply
a clock signal (0~5V, square wave) on the “EXT_CLK”
test point.
7. (Optional) The outputs of LTM4650-1 can track another
supply. The output voltage tracks the voltage on TRACK
when a valid signal is applied on the test point.
8. (Optional) DC2455A-B can be configured to a dual
outputs configuration with VOat 125A load current
and VO2 at 25A load current. Stuff 0Ω resistor on R61
and 0.1µF on C14. Remove R22, R23, R24, R26, R27,
R28, R32, R33, R35. Output voltage VO2 is set by R37
based on the equation VO2 = 0.6V(1 + 60.4k/R37).
performance summary
Specifications are at TA= 25°C
PARAMETER CONDITIONS / NOTES VALUE
Input Voltage Range 4.5V ~ 15V
Output Voltage VOUT VIN = 4.5V to 15V, IOUT = 0A to 150A, JP5: 1.0V 1.0V ± 1.5% (0.985V ~ 1.015V)
Maximum Continuous Output Current De-rating is necessary for certain VIN, VOUT and thermal
conditions, see data sheet for detail.
150A
Default Operating Frequency 500kHz
Resistor Programmable Frequency Range 400kHz – 780kHz
External Clock Sync. Frequency Range 400kHz – 780kHz
Efficiency VIN = 12V, VOUT = 1.0V, IOUT = 150A, fSW = 500kHz 86.1% See Figure 3
Load Transient VIN = 12V, VOUT = 1.0V, ISTEP = 72A to 112.5A < 53mV, See Figure 4

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dc2455abf
DEMO MANUAL DC2455A-B
Quick start proceDure
+–
+–
1mΩ
VOUT0
LOAD
0A~150A
+–
VIN
4.5V TO 16V
++
––
Figure 2. Test Setup of DC2455A-B
Figure 3. Measured Efficiency VIN = 12V, fSW = 500kHz
LOAD CURRENT (A)
0
EFFICIENCY (%)
100
95
65
90
85
80
60
75
70
4020 60
DC2455AB F03
14080 120100
VO= 1V
VO= 1.5V

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dc2455abf
DEMO MANUAL DC2455A-B
Quick start proceDure
X-AXIS (?)
DC2455AB F04
1V VO(20MHz BW)
20mV/DIV
AC-COUPLED
75A TO 112.5A
LOAD
X-AXIS (?)
DC2455AB F05
VOUT (20MHz BW)
5mV/DIV
Figure 4. Load Transient 75A to 112.5A
(VIN = 12V, VOUT1 = 1V, fSW = 500kHz)
Figure 5. Output Voltage Ripple (VIN = 12V,
VOUT1 = 1V, IOUT = 150A, fSW = 500kHz)
Figure 6. Thermal Performance at VIN = 12V, VOUT = 1V, IOUT = 150A, TA= 23.8°C, 200LFM Air Flow

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dc2455abf
DEMO MANUAL DC2455A-B
parts List
ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER
Required Circuit Components
1 1 CIN1 CAP, 150µF 25% 25V ALUM SUN ELECT., 25HVH150M
2 2 CIN2, CIN11 CAP, 1206 1µF 10% 25V X5R TAIYO YUDEN, TMK316BJ105KD-T
3 8 CIN3-CIN10 CAP, 1210 22µF 10% 25V X5R AVX, 12103D226KAT2A
4 4 CIN12-CIN15 CAP, 1210 22µF 10% 25V X5R AVX, 12103D226KAT2A
5 16 CO1, CO2, CO5, CO6, CO7, CO8, CO11, CO13,
CO15, CO16, CO24, CO55, CO56, CO57,
CO58, CO59
CAP, 1206 220µF 20% 4V X5R MURATA, GRM31CR60G227ME11L
6 8 CO20, CO21, CO26, CO27, CO33, CO36,
CO52, CO54
CAP, 1206 220µF 20% 4V X5R MURATA, GRM31CR60G227ME11L
7 1 C1 CAP, 0603 330pF 10% 50V X7R AVX, 06035C331KAT2A-CT
8 4 C4, C10, C18, C22 CAP, 0603 4.7µF 20% 10V X5R TAIYO YUDEN, LMK107BJ475MA-T
9 7 C6, C11, C19, C23, COUT26, C42, C43 CAP, 0603 1µF 10% 10V X7R TAIYO YUDEN, LMK107BJ105KA-T
10 1 C7 CAP, 0603 0.1µF 10% 25V X7R AVX, 06033C104KAT2A
11 1 C31 CAP, 0603 15nF 10% 50V X7R AVX, 06035C153KAZ2A
12 1 C39 CAP, 0603 100nF 10% 100V X7R MURATA, GRM188R72A104KA35D
13 1 C40 CAP, 0603 150pF 5% 50V C0G AVX, 06035A151JAT2A
14 2 C41, C48 CAP, 1210 100µF 10V X5R MURATA, GRM32ER61A107ME20L
15 8 C41, C44, C45, C48, C52, C53, C54, C55 CAP, 1210 100µF 10% 6.3V X5R MURATA, GRM32ER60J107ME20L
16 1 C46 CAP, 1210 10µF 16V X5R MURATA, GRM32DR61C106KA01L
17 1 C47 CAP, 0603 220pF 10% 50V X7R AVX, 06035C221KAT2A
18 1 C49 CAP, 0603 47nF 10% 50V X7R AVX, 06035C473KAZ2A
19 1 L1 IND, 68µH, CDRH105 SUMIDA CDRH105RNP-680N
20 2 Q1, Q2 MOSFET, N-CH D-S 40V TO252 VISHAY, SUD50N04-8M8P-4GE3
21 4 R1, R3, R25, R29 RES, 0603 10Ω 5% 1/10W VISHAY, CRCW060310R0JNEA
22 9 R2, R9, R14, R21, R31, R39, R43, R47, R51 RES, 0603 121kΩ 1% 1/10W VISHAY, CRCW0603121KFKEA
23 4 R4, R36, R41, R98 RES, 0603 10kΩ 5% 1/10W VISHAY, CRCW060310K0JNEA
24 1 R11 RES, 0603 1.74kΩ 1% 1/10W VISHAY, CRCW06031K74FKEA
25 1 R15 RES, 0603 90.9kΩ 1% 1/10W VISHAY, CRCW060390K9FKEA
26 1 R16 RES, 0603 60.4kΩ 1% 1/10W VISHAY, CRCW060360K4FKEA
27 1 R17 RES, 0603 40.2kΩ 1% 1/10W VISHAY, CRCW060340K2FKEA
28 1 R18 RES, 0603 30.1kΩ 1% 1/10W VISHAY, CRCW060330K1FKEA
29 1 R89 RES, 0603 2Ω 1% 1/10W VISHAY CRCW06032R00FNEA
30 1 R92 RES, 0603 3.3Ω 1% 1/10W VISHAY, CRCW06033R3FKEA
31 1 R93 RES, 0603 154kΩ 1% 1/10W VISHAY, CRCW0603154KFKEA
32 1 R94 RES, 0603 1MΩ 5% 1/10W VISHAY CRCW06031M00JNEA
33 3 R95, R96, R107 RES, 0603 20kΩ 5% 1/10W VISHAY, CRCW060320K0JNTA
34 1 R97 RES, 0603 681kΩ 1% 1/10W VISHAY, CRCW0603681KFKEA
35 1 R99 RES, 0603 301Ω 1% 1/10W VISHAY, CRCW0603301RFKEA
36 1 R100 RES, 0603 82.5Ω 1% 1/10W VISHAY, CRCW060382R5FKEA
37 2 R101, R102 RES, 2512 0.010Ω 1% 1W VISHAY, WSL2512R01000FEA
38 1 R103 RES POT, 5k BOURNS 3386P-1-502-LF
39 1 R104 RES, 0603 1kΩ 1% 1/10W VISHAY, CRCW06031K00FKEA

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dc2455abf
DEMO MANUAL DC2455A-B
parts List
ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER
40 1 R105 RES, 0603 105kΩ 1% 1/10W VISHAY CRCW0603105KFKEA
41 1 R106 RES, 0603 80.6kΩ 1% 1/10W VISHAY CRCW060380K6FKEA
42 3 U1, U2, U3 IC, VOLTAGE REGULATOR, BGA LINEAR TECH., LTM4650EY-1B#PBF
43 1 U5 IC, TimerBlox
®
LINEAR TECH., LTC6992IS6-1#PBF
44 1 U6 IC, OP-AMP, SINGLE, BIPOLAR LINEAR TECH., LT1803IS5#PBF
45 1 U7 IC, LTC3630EMSE LINEAR TECH., LTC3630EMSE#PBF
Additional Demo Board Circuit Components
1 0 CIN16-CIN19, CO22, CO28, CO30, CO32,
CO34, CO35, CO48, CO50
CAP, OPTION OPTION
2 0 CO3, CO9, CO14, CO17, CO18, CO38, CO40,
CO42, CO45, CO46
CAP, 1210 OPTION OPTION
3 0 CO4, CO10, CO12, CO19, CO23, CO25, CO29,
CO31, CO37, CO39, CO41, CO43, CO44,
CO47, CO49, CO51, CO53
CAP, 7343 OPTION OPTION
4 0 C2, C3, C5, C8, C9, C12, C17, C20, C21, C29,
C30, C32
CAP, 0603 OPTION OPTION
5 0 R5, R7, R8, R10, R30, R37, R38, R42, R44,
R48, R49, R50, R52, R53, R55, R61, R64,
R87
RES, 0603 OPTION OPTION
6 13 R6, R19, R20, R27, R28, R32, R33, R35,
R40, R45, R62, R63, R91
RES, 0603 0Ω JUMPER VISHAY, CRCW06030000Z0EA
7 2 R13, R34 RES, 0603 0Ω JUMPER VISHAY, CRCW06030000Z0EA
8 4 R22, R23, R24, R26 RES, 2010 0Ω JUMPER VISHAY, CRCW20100000ZEA9
9 1 R60 RES, 1206 0Ω JUMPER VISHAY, CRCW12060000ZOEA
10 0 U4 DO NOT STUFF
Hardware: For Demo Board Only
1 11 E1-E4, E6-E9, E12, E13, E22 TESTPOINT, TURRET, .063" MILL MAX, 2308-2-00-80-00-00-07-0
2 0 E5, E10, E11, E14, E15, E16, E17, E18, E23,
E24, E25, E26, E27, E28, E29, E30
TEST PAD SMD
3 2 E33, E34 TESTPOINT, TURRET, .094" MILL MAX, 2501-2-00-80-00-00-07-0
4 4 JP1, JP2, JP9, JP10 HEADER, 3 PIN 2mm SINGLE ROW WURTH ELEKTRONIK, 620-003-111-21
5 5 JP4, JP5, JP6, JP7, JP8 HEADER, 2 PIN 2mm SINGLE ROW WURTH ELEKTRONIK, 620-002-111-21
6 6 J1, J2, J3, J4, J13, J14 STUD, TEST PIN PEM, KFH-032-10
7 12 J1, J2, J3, J4, J13, J14 (×2) NUT, BRASS PL # 10-32 ANY, 10-32M/S BR PL
8 6 J1, J2, J3, J4, J13, J14 LUG RING, #10 KEYSTONE, 8205
9 6 J1, J2, J3, J4, J13, J14 WASHER, TIN PLATED BRASS ANY, #10EXT BZ TN
10 2 J11, J12 CON, BNC, 5 PINS CONNEX, 112404
11 5 XJP1, XJP2, XJP4, XJP9, XJP10 SHUNT 2mm WURTH ELEKTRONIK, 608-002-134-21
12 4 MTGS AT 4 CORNERS STAND-OFF, NYLON KEYSTONE, 8833

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dc2455abf
DEMO MANUAL DC2455A-B
schematic Diagram
5
5
4
4
3
3
2
2
1
1
D
D
C
C
B
B
A
A

VOUT SELECT
NOTE:UNLESSOTHERWISESPECIFIED,
1.ALLCAPACITORS,RESISTORS0603.
ASSY I.C.
‐A U1,U2
U1,U2,U3 U1,U2,U3,U4
‐B ‐C
100A 150A 200A
Iout
OPT
0
OPT
R13
OPT
0 0
R34
OPT 22uF 22uF
Cin12, 13, 14, 15
OPT OPT 22uF
Cin16, 17, 18, 19
OPT
220uF 220uF
Co20, 21,26,27
OPT OPT
220uF
Co34,35,48,50
*
*Co33,36,52,54
Co22,28,30,32
LTM4650EY‐1
DEMOCIRCUIT2455A‐(A,B,C)
LT JL
VFB PGOOD COMP RUN
TRACK
VOUT
VFB PGOOD COMP RUN TRACK DIFFP DIFFN
VFB
PGOOD COMP
CLKOUT_U1
RUN TRACK VFB
VIN
INTVCC_U1
INTVCC_U1
VOUT
VO+
VO-
VO+
INTVCC_U1
VIN
VO+ VO-
VOUT
EXTVCC
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
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1
Monday, May 23, 2016
15
HIGH EFFICIENCY, POLYPHASE, DC/DC
N/A
STEP-DOWN MODULE REGULATOR
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
1
Monday, May 23, 2016
15
HIGH EFFICIENCY, POLYPHASE, DC/DC
N/A
STEP-DOWN MODULE REGULATOR
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
1
Monday, May 23, 2016
15
HIGH EFFICIENCY, POLYPHASE, DC/DC
N/A
STEP-DOWN MODULE REGULATOR
REVISION HISTORY
DESCRIPTION DATE APPROVEDECO REV
JL
PRODUCTION-1 05/22/16
REVISION HISTORY
DESCRIPTION DATE APPROVEDECO REV
JL
PRODUCTION-1 05/22/16
REVISION HISTORY
DESCRIPTION DATE APPROVEDECO REV
JL
PRODUCTION-1 05/22/16
E23
Vout
+
CO4
OPT
7343
C1
330pF
+
CO39
OPT
7343
J1
4.5V -15V
VIN
CO9 OPT 1210
CO8 220uF 1210 4V
E5 SW1-1
CIN6
22uF 25V
1210
C6
1uF 10V
R60
0 Ohm
1206
R9
121k
1%
CO1 220uF
4V 1210
U1
LTM4650EY-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
R62 0 Ohm
E2
VO+
R16
60.4K
1%
CIN4
22uF 25V
1210
C5
OPT
C2
OPT
R7 OPT
+
CIN1 150uF
25V
R1
10
JP1
EXT
INT
CLK
1 3 2
R13
*
J4
GND
CIN2
1uF 25V 1206
E10 SW2-1
E4
VIN-
CIN3
22uF 25V
1210
R18
30.1K
1%
J3
GND
R8
OPT
+
CO10 OPT 7343
R17
40.2K
1%
CO42
OPT 1210
R5
OPT
C31 15nF
CO6 220uF 4V 1210
J2
0.6 - 1.8V
VOUT
E22
SGND
R4
10K
CO7 220uF 4V 1210
R11
1.74K
R14
121K
1%
CO5 220uF 4V 1210
E1 EXT_CLK
CIN5
22uF 25V
1210
JP5
1.0V
R63
0 Ohm
JP6
1.2V
E6
VO-
CO2 220uF 1210 4V
JP7
1.5V
R2
121K
1%
JP4
0.9V
C7 0.1uF
JP2
ON
OFF
RUN
1 3 2
JP8
1.8V
E9
TRACK
E7
PGOOD
+
CO41 OPT
7343
CO3
OPT
1210
R3
10
R6 0 Ohm
C4
4.7uF
10V
E3
VIN+
E24 Vout
C3 OPT
CO40
OPT
1210
R10
OPT
R15
90.9K
1%
E8
EXTVCC

8
dc2455abf
DEMO MANUAL DC2455A-B
schematic Diagram
5 5
4 4
3 3
2 2
1 1
D
D
C
C
B B A A

REMOVE 0 OHM JUMPERS FOR SEPARATE VOUT2_U2.
DEMOCIRCUIT2455A‐(A,B,C)
LTM4650EY‐1
LT JL
COMP_U2 RUN_U2
COMP
TRACK_U2
VFB PGOOD RUN TRACK
PGOOD_U2
DIFFOUT_U2
DIFFOUT_U2
VFB_U2
PGOOD_U2 VFB_U2 RUN_U2 COMP_U2 TRACK_U2
COMP
CLKOUT_U1
CLKOUT_U2
RUN TRACK PGOOD VFB
VOUT
INTVCC_U2
VOUT2_U2
VIN
EXTVCC
INTVCC_U2
VO2+
VO2-
VO2+ VO2-
INTVCC_U2
VO2+
VOUT2_U2VOUT
VOUT2_U2
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
1
Monday, May 23, 2016
25
HIGH EFFICIENCY, POLYPHASE, CD/CD
N/A
STEP-DOWN MODULE REGULATOR
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
1
Monday, May 23, 2016
25
HIGH EFFICIENCY, POLYPHASE, CD/CD
N/A
STEP-DOWN MODULE REGULATOR
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
1
Monday, May 23, 2016
25
HIGH EFFICIENCY, POLYPHASE, CD/CD
N/A
STEP-DOWN MODULE REGULATOR
R22
0 Ohm
2010
C11
1uF 10V
CO14
OPT
1210
C13 OPT
CIN9
22uF 25V
1210
J13
GND
R23
0 Ohm
2010
R27
0 Ohm
+
CO12 OPT 7343
C8 OPT
C32 OPT
J14
VOUT2_U2
VOUT/
+
CO43 OPT 7343
C9 OPT
+
CO25 OPT
7343
R24
0 Ohm
2010
R21
121K
1%
C15 OPT
E25 Vout
R31
121K
1%
R20
0 Ohm
R25
10
+
CO44 OPT 7343
CO56
220uF 4V 1210
R61
OPT
CO38 OPT
1210
+
CO19 OPT 7343
R26
0 Ohm
2010
CO45
OPT
1210
CO57
220uF 4V 1210
CO13 220uF 1210 4V
CO46
OPT 1210
U2
LTM4650EY-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
R19
0 Ohm
R34 *
R64
OPT
CIN10
22uF 25V
1210
R32
0 Ohm
R33
0 Ohm
R35
0 Ohm
C14 OPT
E26
Vout2
E11 SW1-2
R28
0 Ohm
R38
OPT
CO18 OPT 1210
CIN8
22uF 25V
1210
CO16 220uF 1210 4V
R37
OPT
R36
10K
C10
4.7uF
10V
CO11
220uF 4V 1210
R29
10
CIN7
22uF 25V
1210
CO15 220uF 4V 1210
E13
VO2-
E12
VO2+
C12 OPT
R30
OPT
E14
SW2-2
CO17 OPT 1210

9
dc2455abf
DEMO MANUAL DC2455A-B
schematic Diagram
5
5
4
4
3
3
2
2
1
1
D D C C B B A A

DEMOCIRCUIT2455A‐(A,B,C)
LTM4650EY‐1
LT JL
COMP RUN
COMP
CLKOUT_U2 CLKOUT_U3
PGOOD
RUN
VFB
TRACK
PGOOD
TRACK
VFB
COMP
CLKOUT_U2 CLKOUT_U3
RUN VFB PGOOD TRACK
VOUT
INTVCC_U3
VOUT
VIN
EXTVCC
INTVCC_U3
INTVCC_U3
INTVCC_U3
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
1
Monday, May 23, 2016
35
HIGH EFFICIENCY, POLYPHASE, DC/DC
N/A
STEP-DOWN MODULE REGULATOR
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
1
Monday, May 23, 2016
35
HIGH EFFICIENCY, POLYPHASE, DC/DC
N/A
STEP-DOWN MODULE REGULATOR
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
1
Monday, May 23, 2016
35
HIGH EFFICIENCY, POLYPHASE, DC/DC
N/A
STEP-DOWN MODULE REGULATOR
+
CO49 OPT
7343
C17 OPT
+
CO23
OPT
7343
CO58 220uF 4V
1210
R39
121K
1% CO20
*
4V
1210
+
CO29 OPT
7343
CO28 * 1210
4V
C16 OPT
R40 0 Ohm
CIN11
1uF 25V 1206
E16
SW2-3
CIN15
* 25V
1210
+
CO47
OPT
7343
U3
LTM4650EY-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
E27 Vout CO21
* 1210
4V
R44
OPT
R41
10K
CIN13
* 25V
1210
R43
121K
1%
R42
OPT
CO27 *
1210
4V
CO48 * 1210
4V
CO50 * 1210
4V
E28 Vout
CO26
* 1210
4V
E15 SW1-3
C19
1uF 10V
C18
4.7uF
10V
CO22 * 1210
4V
CIN14
* 25V
1210
CO24 220uF 4V 1210
CIN12
* 25V
1210

10
dc2455abf
DEMO MANUAL DC2455A-B
schematic Diagram
5
5
4
4
3
3
2
2
1
1
D
D
C
C
B
B
A
A

DEMOCIRCUIT2455A‐(A,B,C)
LTM4650EY‐1
LT
JL
COMP RUN COMP TRACK VFB
PGOOD
RUN VFB TRACK PGOOD
CLKOUT_U3
VFB COMP
CLKOUT_U3
RUN TRACK PGOOD
INTVCC_U4
VOUT
VOUT
VIN
EXTVCC
INTVCC_U4
VO+
VO-
VOUT
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
1
Monday, May 23, 2016
45
HIGH EFFICIENCY, POLYPHASE, DC/DC
N/A
STEP-DOWN MODULE REGULATOR
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
1
Monday, May 23, 2016
45
HIGH EFFICIENCY, POLYPHASE, DC/DC
N/A
STEP-DOWN MODULE REGULATOR
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
1
Monday, May 23, 2016
45
HIGH EFFICIENCY, POLYPHASE, DC/DC
N/A
STEP-DOWN MODULE REGULATOR
R53
OPT
R49
OPT
C22
4.7uF
10V
R51
121K
1%
CO52 * 1210
4V
CO30 * 4V 1210
R47
121K
1%
CO36
* 1210
4V
R48
OPT
CIN19
* 25V
1210
R52
OPT
C23
1uF 10V
CO54
*
1210
4V
C21
OPT
R45
0 Ohm
R50
OPT
CO34
*
4V
1210
CO33 * 1210
4V
CIN16
* 25V
1210
E18 SW2-4
C30
OPT
R55
OPT
CO32 * 1210 4V
CIN18
* 25V
1210
C29
OPT
CO35
* 1210
4V
E17
SW1-4
+
CO53 OPT 7343
E29 Vout CO55
220uF 4V 1210
+
CO37 OPT
7343
CO59 220uF 4V 1210
CIN17 *
25V
1210
E30 Vout
U4
LTM4650EY-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
+
CO51 OPT 7343
C20
OPT
+
CO31 OPT 7343

11
dc2455abf
DEMO MANUAL DC2455A-B
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
VOUT
PULSE
DYNAMIC LOAD CIRCUIT
70Hz, 3% Duty Cycle
INT EXT
1%
IOUT STEP
OPTIONAL 5V BIAS
ON
OFF
BIAS
LT
JIAN L
LTM4650EY‐1
DEMOCIRCUIT2455A‐(A,B,C)
LT
JL

+5V
VIN
+5V
EXTVCC
VOUT
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
1
Monday, May 23, 2016
55
HIGH EFFICIENCY, POLYPHASE, DC/DC
N/A
STEP-DOWN MODULE REGULATOR
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
1
Monday, May 23, 2016
55
HIGH EFFICIENCY, POLYPHASE, DC/DC
N/A
STEP-DOWN MODULE REGULATOR
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
1
Monday, May 23, 2016
55
HIGH EFFICIENCY, POLYPHASE, DC/DC
N/A
STEP-DOWN MODULE REGULATOR
J12
R100
82.5
1%
J11
R89 2
E34
GND
R106 80.6k
1%
R95 20K
E33
EXT PULSE
R105 105K 1%
U6 LT1803IS5
VOUT
1
V-
2
+IN
3
-IN
4
V+
5
C43 1uF
C41 100uF 10V 1210
C46 10uF 16V 1210
C42
1uF
C45 100uF 1210 6.3V
C49
47nF
R104
1K
C53 100uF 1210 6.3V
Q1
SUD50N04-8M8P-4EG3
U5 LTC6992IS6-1
MOD
1
GND
2
SET
3
DIV
4
V+
5
OUT
6
C55 100uF 1210 6.3V
R87 OPT
C39 100nF
R97 681K
1%
JP10
1
2
3
R101 0.01 2512
R107 20K
C48
100uF
10V 1210
C44 100uF 1210 6.3V
R91 0 Ohm
C47 220pF
R96 20K
R94 1M
R102 0.01
2512
R99
301
R103
5K
C52 100uF 1210 6.3V
Q2
SUD50N04-8M8P-4EG3
C40 150pF
C54 100uF 1210 6.3V
R92 3.3
1%
R98
10K
COUT26 1uF
L1
68uH
SUMIDA CDRH105
C51 OPT
U7
LTC3630EMSE
SW
1
VIN
3
FBO
12
VPRG1
7
VPRG2
6
GND
8
VFB
9
SS
10
ISET
11
GND
14
RUN
5
GND
16
GND
17
R93
154k
JP9
1
2
3

12
dc2455abf
DEMO MANUAL DC2455A-B
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
[phone] ●FAX: [phone] ●www.linear.com
© LINEAR TECHNOLOGY CORPORATION 2016
LT 0616 • 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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