Linear Technology DC2378A-B User manual

1
dc2378abfa
DEMO MANUAL DC2378A-B
Description
LTM4650-1
High Efficiency, Single 50A or Dual 25A
Step-Down Power µModule Regulator
Demonstration circuit DC2378A-B features the
LT M
®
4650EY-1, the high efficiency, high density, dual
25A, single 50A, switch mode step-down power module
regulator. The input voltage isfrom4.5Vto15V. The output
voltage is programmable from 0.6V to 1.8V. DC2378A-B
can deliver 25A maximum current from each channel. As
explained in the data sheet, output current derating is nec-
essary for certain VIN, VOUT, and thermal conditions. The
board operates in continuous conduction mode in heavy
loadconditions. For highefficiency atlowloadcurrents, the
MODE jumper(JP1) selects pulse-skipping mode for noise
sensitive applications or Burst Mode
®
operation in less
noisesensitiveapplications. Tw o outputs can be connected
in parallel for a single 50A output solution with optional
jumper resistors. The board allows the user to program L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks
of Linear Technology Corporation. All other trademarks are the property of their respective
owners.
how its output ramps up and down through the TRACK/
SS pin. The output can be set up to either coincidentally or
ratiometrically track with another supply’s output. Remote
output voltage sensing is available for improved output
voltage regulation at the load point. These features and
the availability of the LTM4650EY-1 in a compact 15mm
×15mm × 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 DC2378A-B.
Design files for this circuit board are available at
http://www.linear.com/demo/DC2378A-B
Figure 1. LTM4650-1/DC2378A-B Demo Board

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dc2378abfa
DEMO MANUAL DC2378A-B
Quick start proceDure
Demonstration circuit DC2378A-B is easy to set up to
evaluate the performance of the LTM4650EY-1. Please
refer to Figure 2 for proper measurement setup and follow
the procedure below:
1. Place jumpers in the following positions for a typical
application:
JP1 JP2 JP3 JP4 JP5
MODE RUN1 RUN2 TRACK1
SEL.
TRACK2
SEL.
CCM ON ON SOFT-
START
SOFT-
START
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
voltage in channel 1 should be 1.5V±1.5% (1.4775V
~ 1.5225V) and the output voltage in channel 2 should
be 1V ±1.5% (0.985V ~ 1.015V).
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 J1 and J2 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 current amplitude. The output transient current
can be monitored at the BNC connector J3 (10mV/A).
The pulse signal should have very small duty cycle (<
1%) to limit the thermal stress on the transient load
circuit. Switch the jumper resistors R34 or R35 (on the
backside of boards) to apply load transient on channel
1 or channel 2 correspondingly.
6. (Optional) LTM4650-1 can be synchronized to an
external clock signal. Place the JP1 jumper on EXT_CLK
and apply a clock signal (0V~ 5V, square wave) on the
CLKIN test point.
7. (Optional) The outputs of LTM4650-1 can track another
supply. The jumpers JP4 and JP5 allow choosing soft-
start or output tracking. If tracking external voltage is
selected, the corresponding test points, TRACK1 and
TRACK2, need to be connected to a valid voltage signal.
8. (Optional) LTM4650-1 can be configured for a 2-phase
single output at up to 50A on DC2378A-B. Install 0Ω
resistors on R14, R17, R28, R39, R43, R44, R45 and
remove R7, R19. Output voltage is set by R25 based
on equation VOUT = 0.6V(1 + 60.4k/R25).
performance summary
Specifications are at TA= 25°C
PARAMETER CONDITIONS MIN TYP MAX UNITS
Input Voltage Range 4.5 15 V
Output Voltage VOUT1 VIN = 4.5V ~ 15V, IOUT1 = 0A ~ 25A, JP1: CCM 1.5 ±1.5% V
Output Voltage VOUT2 VIN = 4.5V ~ 15V, IOUT2 = 0A ~ 25A, JP1: CCM 1 ±1.5% V
Per-Channel Maximum Continuous Output
Current
Derating Is Necessary for Certain VIN, VOUT and
Thermal Conditions, See Data Sheet for Detail.
25
(Per-Channel)
A
Default Operating Frequency 500 kHz
Resistor Programmable Frequency Range 250 780 kHz
External Clock Sync. Frequency Range 400 780 kHz
Efficiency of Channel 1 VIN = 12V, VOUT1 = 1.5V, IOUT1 = 25A, fSW = 500kHz 88.8
See Figure 4
%
Efficiency of Channel 2 VIN = 12V, VOUT2 = 1V, IOUT2 = 25A, fSW = 500kHz 86.5
See Figure 5
%
Load Transient of Channel 1 VIN = 12V, VOUT1 = 1.5V, ISTEP = 12.5A ~ 18.75A See Figure 6
Load Transient of Channel 2 VIN = 12V, VOUT2 = 1V, ISTEP = 12.5A ~ 18.75A See Figure 7

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dc2378abfa
DEMO MANUAL DC2378A-B
Quick start proceDure
Figure 3. Measuring Output Voltage Ripple
Figure 2. Test Setup of DC2378A-B
+ –
VOUT GND
COUT

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dc2378abfa
DEMO MANUAL DC2378A-B
Quick start proceDure
Figure 4. Measured Efficiency on Channel 1
(VOUT1 = 1.5V, fSW = 500kHz, Channel 2 Disabled)
Figure 6. Measured Channel 1 12.5A to 18.75A Load Transient
(VIN = 12V, VOUT1 = 1.5V)
Figure 5. Measured Efficiency on Channel 2
(VOUT2 = 1V, fSW = 500kHz, Channel 1 Disabled)
Figure 7. Measured Channel 2 12.5A to 18.75A Load Transient
(VIN = 12V, VOUT2 = 1V)
OUTPUT LOAD CURRENT (A)
0
EFFICIENCY (%)
95
90
80
85
75
70 15
dc2378aa F04
25
20105
12VIN, 1.5VO
5VIN, 1.5VO
OUTPUT LOAD CURRENT (A)
0
EFFICIENCY (%)
95
90
80
85
75
70 15
dc2378aa F05
25
20105
12VIN, 1VO
5VIN, 1VO
dc2378aa F06
12.5A TO 18.75A
1.5V OUTPUT (20MHz BW) [20mV/DIV]
dc2378aa F07
12.5A TO 18.75A
1V OUTPUT (20MHz BW) [20mV/DIV]

5
dc2378abfa
DEMO MANUAL DC2378A-B
Quick start proceDure
Figure 8. Measured Output Voltage Ripple at 12V Input,
1.5V/25A with Standard Demo Circuit Default Setup
Figure 10. Thermal Capture at 12VIN, 1.5VOUT at 25A and 1VOUT at 25A
(Ambient Temperature = 23°C, 200 LFM Airflow and No Heat Sink)
Figure 9. Measured Output Voltage Ripple at 12V Input,
1V/25A with Standard Demo Circuit Default Setup
dc2378aa F08
1.5V OUTPUT (20MHz BW) [20mV/DIV]
dc2378aa F09
1V OUTPUT (20MHz BW) [20mV/DIV]

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dc2378abfa
DEMO MANUAL DC2378A-B
parts List
ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER
Required Circuit Components
1 1 CIN1 CAP., ALUM. ELECT.,330µF, 25V, 20% PANASONIC, 25SVPF330M
2 4 CIN2, CIN3, CIN4, CIN5 CAP., 22µF,X5R, 25V, 10%,1210 MURATA, GRM32ER61E226KE15L
3 4 COUT9, COUT10, COUT12, COUT18 CAP., POSCAP, 470µF, 2.5V, 0.005Ω, 7343 PANASONIC, ETPF470M5H
4 10 COUT2, COUT3, COUT4, COUT5, COUT6 CAP., 100µF, X5R, 6.3V, 20%, 1210 AVX, 12106D107MAT2A
COUT8, COUT13, COUT14, COUT15,
COUT16
5 1 C1 CAP., 4.7µF, X5R, 16V,20%, 0805 KEMET, C0805C475M4PACTU
6 1 C2 CAP., 1µF,X7R, 25V,10%, 0805 AVX, 08053C105KAT2A
7 2 C5, C7 CAP., 0.1µF, X5R, 25V, 10%, 0603 AVX, 06033D104KAT2A
8 1 C10 CAP., 220pF, X7R, 100V,10%, 0603 AVX, 06031C221KAT2A
9 1 C12 CAP., 47pF, X7R, 50V,10%, 0603 AVX, 06035A470J4T2A
10 4 C13, C14, C15, C16 CAP., 1µF, X7R, 10V,10%, 0603 AVX, 0603ZC105KAT2A
11 1 C17 CAP., 3.3nF, X7R, 50V,10%, 0603 AVX, 06035C332KAT2A
12 1 C18 CAP., 4.7nF, X7R, 50V,10%, 0603 AVX, 06035C472KAT2A
13 1 Q1 XSTR., N-CH, 40V, DPAK-2, TO-252 VISHAY, SUD50N04-8M8P-4GE3
14 4 R1, R3, R22, R26 RES., 10 OHMS, 1/10W, 1%, 0603 NIC, NRC06F10R0TRF
15 1 R5 RES., 100k, 1/10W, 1%, 0603 VISHAY,CRCW0603100KFKEA
16 4 R9, R12, R15, R18 RES.., 60.4k, 1/10W,1%, 0603 VISHAY, CRCW060360K4FKEA
17 2 R10, R13 RES.., 6.04k, 1/10W,1%, 0603 VISHAY, CRCW06036K04FKEA
18 1 R19 RES., 90.9k, 1/10W,1%, 0603 VISHAY, CRCW060390K9FKEA
19 3 R24, R27, R36 RES., 10k, 1/10W,1%, 0603 YAGEO, RC0603FR-0710KL
20 1 R25 RES., 40.2k, 1/10W,1%, 0603 VISHAY,CRCW060340K2FKEDA
21 1 R30 RES., 121k, 1/10W,1%, 0603 VISHAY,CRCW0603121KFKEA
22 1 R37 RES., HIGH POWER, 0.01Ω, 2W,1%, 2512 VISHAY, WSL2512R0100FEA18
23 1 R46 RES., 21k, 1/10W,1%, 0603 YAGEO, RC0603FR-0721KL
24 1 R47 RES., 20k, 1/10W,1%, 0603 YAGEO, RC0603FR-0720KL
25 1 U1 I.C., 16X16X5.01-BGA LINEAR TECH., LTM4650EY-1#PBF
Additional Demo Board Circuit Components
1 0 COUT1, COUT7, COUT11, COUT17 CAP., OPT, 7343 OPT
2 0 C3, C4, C6, C8, C9, C11 CAP., OPTION, 0603 OPT
3 0 R2, R4, R6, R8, R11, R14, R16, R17,
R20, R23, R28, R31, R33, R39, R40,
R41, R42, R48
RES., OPTION, 0603 OPT
4 4 R7, R21, R29, R32 RES., 0Ω, 1/10W, 0603 VISHAY, CRCW06030000Z0EA
5 1 R34 RES., 0Ω, 1/2W, 2010 VISHAY, CRCW20100000Z0EF
6 0 R35 RES., OPTION, 2010 OPT
7 0 R38, R43, R44, R45 RES., OPTION, 2512 OPT
Hardware: For Demo Board Only
1 16 E1, E3, E4, E5, E6, E7, E8, E9, E10, E12,
E13, E14, E15, E16, E17, E18
TEST POINT, TURRET, .094" MTG. HOLE MILL-MAX, 2501-2-00-80-00-00-07-0
2 1 JP1 CONN., HEADER, 2×4, 2mm WURTH ELEKTRONIK, 62000821121
3 3 JP2, JP3, JP4 CONN., HEADER, 1×3, 2mm WURTH ELEKTRONIK, 62000311121

7
dc2378abfa
DEMO MANUAL DC2378A-B
parts List
ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER
4 1 JP5 CONN., HEADER, 2×3, 2mm WURTH ELEKTRONIK, 62000621121
5 5 XJP1, XJP2, XJP3, XJP4, XJP5 SHUNT, 2mm WURTH ELEKTRONIK, 60800213421
6 3 J1, J2, J3 CONN., BNC STR PCB JK, THRU- HOLE, 5 PINS CONNEX 112404
7 2 J4, J5 CONN., JACK, BANANA, NON-INSULATED, 0.218" KEYSTONE, 575-4
8 4 J6, J7, J8, J9 STUD, TESTPIN PEM KFH-032-10
9 8 J6, J7, J8, J9 (×2) NUT, BRASS 10-32 ANY #10-32
10 4 J6, J7, J8, J9 RING, LUG #10 KEYSTONE, 8205, #10
11 4 J6, J7, J8, J9 WASHER, TIN PLATED BRASS ANY #10, #10EXT BZ TN
12 4 (STAND-OFF) STANDOFF, NYLON, SNAP-ON, 0.500" KEYSTONE, 8833

8
dc2378abfa
DEMO MANUAL DC2378A-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
VIN+
VIN-
VIN GND
4.5V-15V
VO1+ VO1-
VO2- VO2+
ON
TRACK1
ON
EXT.
SOFT-START
TRACK1 SEL.
NOTE: UNLESS OTHERWISE SPECIFIED 1. ALL RESISTORS AND CAPACITORS ARE 0603.
m
SW2
SW1
VOUT1
VIN INTVCC
VO1+
VO1-
INTVCC
VO1-
VO1+
INTVCC
VOUT1
VO2+
VO2-
VIN
INTVCC
INTVCC
DIFFP
COMP1
VFB1
DIFFN
DIFFOUT
VOUT1S
VOUT1
TRACK1
RUN1
VO2+
VOUT2
VO2-
VOUT2S
RUN2
TRACK2
VFB2
COMP2
INTVCCTEMP
REVISION HISTORY DESCRIPTION DATEAPPROVEDECO REV
PRODUCTION
1 4-26-16
__
JL
REVISION HISTORY DESCRIPTION DATEAPPROVEDECO REV
PRODUCTION
1 4-26-16
__
JL
REVISION HISTORY DESCRIPTION DATEAPPROVEDECO REV
PRODUCTION
1 4-26-16
__
JL
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
1
Tuesday, April 26, 2016
12
STEP-DOWN MODULE REGULATOR
LT
JL
N/A
LTM4650EY-1
DEMO CIRCUIT 2378A-B
HIGH EFFICIENCY, DUAL 25A, SINGLE 50A,
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
1
Tuesday, April 26, 2016
12
STEP-DOWN MODULE REGULATOR
LT
JL
N/A
LTM4650EY-1
DEMO CIRCUIT 2378A-B
HIGH EFFICIENCY, DUAL 25A, SINGLE 50A,
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
1
Tuesday, April 26, 2016
12
STEP-DOWN MODULE REGULATOR
LT
JL
N/A
LTM4650EY-1
DEMO CIRCUIT 2378A-B
HIGH EFFICIENCY, DUAL 25A, SINGLE 50A,
COUT14 100uF
6.3V
1210
E4
R16
OPT
JP3
OFF
RUN2
13
2
E15
TEMP
COUT13 100uF
6.3V
E7
C10 220pF
R19
90.9K
C5
0.1uF
R3 10
J4
E1
CIN4 22uF
1210 25V
COUT2 100uF 6.3V
COUT6
100uF
6.3V
1210
+
COUT1
OPT 2.5V
C4
OPT
C3
OPT
R10 6.04K
JP1
EXT_CLK
PS
CCM
MODE
BM
1 3
2 4 65
7 8
J5
J6
1.5V / 25A
VOUT1
R30 121K
U1
LTM4650EY-1
VIN J9
VIN J10
VIN J11
VIN K2
VIN K3
VIN K4
VIN K9
VIN K10
VIN K11
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 J2
VIN J3
VIN J4
RUN1
F5
TRACK1
E5
VOUT1S
C5
VOUT1
A1
VOUT1
A2
VOUT1
A3
VOUT1
A4
VOUT1
A5
VFB1
D5
SW1
G2
PGOOD1
G9
COMP1
E6
DIFFOUT
F8
DIFFN
E9
DIFFP
E8
FSET
C6
PHASMD
G4
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
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 J1 GND J5 GND J8 GND J12 GND K1 GND K5 GND K6 GND K7 GND K8 GND K12 GND L1 GND L12 GND M1 GND M12
SGND C7 SGND D6 SGND F6 SGND F7 SGND G6 SGND G7
VOUT1
B1
VOUT1
B2
VOUT1
B3
VOUT1
B4
VOUT1
B5
VOUT1
C1
VOUT1
C2
VOUT1
C3
VOUT1
C4
COMP2 E7
PGOOD2 G8
SW2 G11
VFB2 D7
TRACK2 D8
RUN2 F9
VOUT2S C8
TEMP J6
MODE-PLLIN F4
CLKOUT G5
INTVCC H8
EXTVCC J7
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
GND
G3
JP5
VOUT1
TRACK2 SEL.
1 3
2 4
5 6
C7
0.1uF
R46
21K
E12 PGOOD2
E13
EXTVCC
CIN3 22uF
25V
1210
R15 60.4K
R32
0
COUT16
100uF
6.3V
R1 10
C6
OPT
+
COUT17
OPT 7343
+
COUT18
470uF
2.5V 7343
+
COUT10
470uF 2.5V
7343
R42 OPT
E6
CIN2 22uF
25V
1210
R21
0
COUT4 100uF
6.3V
1210
E14
CLKOUT
R7 0
C1
4.7uF
R22 10
COUT15
100uF
6.3V
1210
C2
1uF
R47 20K
R20 OPT
E8
R2
OPT
R6 OPT
R41 OPT
R24 10K
C12
47pF
J9
GND
R27
10K
+
COUT7
OPT 7343
CIN5 22uF
25V
1210
JP2
OFF
RUN1
1 3
2
R5
100K
R8
OPT
C11
OPT
COUT8
100uF
6.3V
R18 60.4K
E10
TRACK2
+
COUT12
470uF 2.5V
7343
R9
60.4K
+
CIN1
330uF 25V
E9
C17
3.3nF
R12
60.4K
C8
OPT
E3
PGOOD1
C9
OPT
R26
10
+
COUT11
OPT 2.5V
JP4
SOFT-START
TRACK
1
3
2
E5
COUT5 100uF
6.3V
1210
R13 6.04K
C18
4.7nF
J7
GND
E16
CLKIN
R29
0
J8
1V / 25A
VOUT2
R25
40.2K
COUT3 100uF 6.3V 1210
+
COUT9 470uF
2.5V 7343
R4
OPT

9
dc2378abfa
DEMO MANUAL DC2378A-B
schematic Diagram
5
5
4
4
3
3
2
2
1
1
D D C C B B A A
OPTIONAL JUMPER FOR SINGLE OUTPUT CONFIGURATION
DIFF SENSING SELECTION
VOUT1
Load Transient Circuit
VOUT2
m
VIN
TEMP INTVCC
RUN1 RUN2
TRACK1 TRACK2
VFB1 VFB2
COMP1 COMP2
VO2- DIFFN VO2+ DIFFP
VOUT1S VOUT1 VOUT2S DIFFOUT
VOUT1 VOUT2
VOUT1 VOUT2
INTVCC
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
1
Tuesday, April 26, 2016
22
STEP-DOWN MODULE REGULATOR
LT
JL
N/A
LTM4650EY-1
DEMO CIRCUIT 2378A-B
HIGH EFFICIENCY, DUAL 25A, SINGLE 50A,
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
1
Tuesday, April 26, 2016
22
STEP-DOWN MODULE REGULATOR
LT
JL
N/A
LTM4650EY-1
DEMO CIRCUIT 2378A-B
HIGH EFFICIENCY, DUAL 25A, SINGLE 50A,
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
1
Tuesday, April 26, 2016
22
STEP-DOWN MODULE REGULATOR
LT
JL
N/A
LTM4650EY-1
DEMO CIRCUIT 2378A-B
HIGH EFFICIENCY, DUAL 25A, SINGLE 50A,
R36
10K
E17
IOSTEP CLK
J3
IOSTEP
R23
OPT
R39
OPT C13
1uF
R35 OPT
2010
Q1 SUD50N04-8M8P-4GE3
2
1
34
R14
OPT
R48
OPT
J1 C14
1uF
R11
OPT
E18
GND
R34
0 OHm
0.5W 2010
R43 OPT 2512
R28
OPT
R45
OPT 2512
R38 OPT
2512
R33
OPT
R17
OPT C16
1uF
R44
OPT 2512
R40
OPT
C15 1uF
R31
OPT
J2
R37
0.010 2W 2512

10
dc2378abfa
DEMO MANUAL DC2378A-B
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
[phone] ●FAX: [phone] ●www.linear.com
© LINEAR TECHNOLOGY CORPORATION 2016
LT 0317 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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