DC2142A - Demo Manual

DEMO MANUAL DC2142A
LTC3875EUJ & LTC3874IUFD
High Efficiency, Single-Output Synchronous
Buck Converter with Very Low DCR Inductor
Description
Demonstration circuit 2142A is a high efficiency, high
density, 4-phase synchronous buck converter with a 4.5V
to 14V input range. It can supply 120A maximum load
current at a 1.0V output. This demo board incorporates
the LTC3875EUJ and LTC3874IUFD controllers.
The LTC 3875 is a feature-rich dual phase synchronous
buck controller with very low DCR current sensing capability, on-chip drivers and remote output voltage sensing. The LTC3874 is a compact dual phase synchronous
buck phase extender with very low DCR current sensing
capability, on-chip drivers and immediate response to
master IC's fault.
®
This board is setup with 0.32mΩ DCR inductor. The temperature compensation function guarantees accurate current limit over a wide temperature range with DCR sensing.
The DC2142 can provide high efficiency, high power density
and compact solutions for telecom and datacom systems,
Performance Summary
PARAMETER
industrial and medical instruments, DC power distribution
systems and computer systems. The LTC3875 is available
in a 40-pin 6mm × 6mm QFN package. The LTC3874 is
available in a 28-lead (4mm × 5mm) QFN Package.
To shut down the converter, set the RUN pin voltage below 1.4V (SW1: OFF). Use the JP1 jumper to select burst
mode, pulse skipping mode or forced continuous mode
operation at light load. Switching frequency is preset at
about 400kHz, and it can be easily modified from 250kHz
to 770kHz. An on-board dynamic circuit is also available
for transient test. The LTC3875 and LTC3874 data sheets
give a complete description of these parts, and must be
read in conjunction with this DC2142A quick start guide
Design files for this circuit board are available at
http://www.linear.com/demo/DC2142A
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.
Specifications are at TA = 25°C
CONDITIONS
VALUE
Output Voltage, VOUT
VIN = 4.5V to 14V, IOUT1 = 0A to 120A
1.0V ±2%
Maximum Output Current, IOUT
VIN = 4.5V to 14V, VOUT1 = 1.0V
120A
Typical Efficiency, VOUT
VIN = 12V, VOUT1 = 1.0 V, IOUT1 = 120A
87.4%
Input Voltage Range
Typical Switching Frequency
4.5V to 14V
400kHz
dc2142af
1
DEMO MANUAL DC2142A
Quick Start Procedure
Demonstration circuit 2142A is easy to set up to evaluate
the performance of the LTC3875EUJ and LTC3874IUFD.
Refer to Figure 1 for the proper measurement equipment
setup and follow the procedure below:
5.Once the proper output voltages are established, adjust the loads within the operating range and observe
the output voltage regulation, ripple voltage and other
parameters.
1.With power off, connect the input power supply to VIN
(4.5V to 14V) and GND (input return).
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.
2.Connect the 1.0V output load between VOUT and GND
(Initial load: no-load).
3.Connect the DVMs to the input and outputs. Set default
jumper position: JP1: CCM; SW1: ON.
4.Turn on the input power supply and check for the proper
output voltages. VOUT should be 1.0V ±2%.
2
dc2142af
DEMO MANUAL DC2142A
Quick Start Procedure
+
–
VOUT
+
–
–
+
+
+
–
–
1mΩ
+
LOAD
(0A ~ 120A)
VIN
4.5V TO 14V
–
dc2142a F01
Figure 1. Proper Measurement Equipment Setup
+
VOUT
–
C40
GND
Figure 2. Measuring Output Voltage Ripple
dc2142af
3
DEMO MANUAL DC2142A
Quick Start Procedure
Efficiency vs Load Current, VOUT = 1.0V
95
EFFICIENCY (%)
90
85
80
75
70
0
20
40
60
80
100
120
LOAD CURRENT (A)
dc2142a F03
Figure 3. Efficiency vs Load Current at VIN = 12V, VOUT = 1.0V, fSW = 400kHz
Figure 4. Thermal Performance at VIN = 12V, VOUT = 1.0V, IOUT = 120A, 200PFM Forced Air Flow
4
dc2142af
DEMO MANUAL DC2142A
Quick Start Procedure
Current Sharing vs Load Current, VOUT = 1.0V
35
CHANNEL 1
CHANNEL 2
CHANNEL 3
CHANNEL 4
CURRENT SHARING (A)
30
±3.6%
25
20
15
10
5
0
0
20
40
60
80
100
120
LOAD CURRENT (A)
dc2142a F05
Figure 5. Current Sharing vs Load Current at VIN = 12V, VOUT = 1.0V, fSW = 400kHz
VOUT (20MHz BW) [5mV/DIV]
Figure 6. Output Voltage Ripple at VIN = 12V, VOUT = 1.0V, IOUT = 120A
dc2142af
5
DEMO MANUAL DC2142A
Quick Start Procedure
VOUT (20MHz BW) [20mV/DIV]
30A TO 60A LOAD STEP
Figure 7. Transient Performance at VIN = 12V, VOUT = 1.0V, IOUT = 30A ~ 60A
Parts List
ITEM
QTY
REFERENCE
PART DESCRIPTION
MANUFACTURER/PART NUMBER
Required Circuit Components
1
8
CIN1, CIN2, CIN3, CIN4, CIN5, CIN6,
CIN7, CIN8
CAP, 1210, 10µF, 20%, 35V X5R
AVX 1210DD106MAT2A
2
14
COUT1, COUT2, COUT6, COUT7,
COUT9, COUT12, COUT13, COUT14,
COUT19, COUT20, COUT24, COUT25,
C39, C40
CAP, 1210, 100µF, 20%, 6.3V X5R
TDK C3225X5R0J107M
3
12
COUT3, COUT4, COUT5, COUT8,
COUT10, COUT11, COUT15, COUT16,
COUT17,COUT18, COUT22, COUT23
CAP, 7343, 330µF, 20%, 6.3V POSCAP
SANYO 6TPF330M9L
4
3
C3, C25, C29
CAP, 0603, 1µF, 20%, 25V X5R
AVX 06033D105KAT2A
5
2
C1, C2
CAP, 270µF, 20%, 16V OSCON
PANASONIC 16SVPC270M
6
4
C4, C30, C31, C46
CAP, 0603, 4.7µF, 10%, 10V X5R
AVX 0603ZD475KAT2A
7
1
C5
CAP, 0603, 10nF, 10%, 16V X7R
AVX 0603YC103KAT2A
8
5
C7, C8, C18, C32, C36,
CAP, 0603, 0.1µF, 10%, 25V X5R
AVX 06033C104KAT2A
9
6
C10, C12, C20, C24, C33, C35
CAP, 0603, 220nF, 10%, 25V X7R
TDK C1608X7R1E224K
10
1
C15
CAP, 0603, 220pF, 5%, 50V C0G
AVX 06035A221JAT2A
11
1
C16
CAP, 0603, 2.2nF, 5%, 50V C0G
MURATA GRM1885C1H222JA01D
12
1
C34
CAP, 0603, 100pF, 10%, 16V X7R
AVX 0603YC101KAT2A
13
1
D1, D2, D3, D4
DIODE, SCHOTTKY 30V, 100mA
CENTRAL SEMI CMDSH-3-TR
14
4
L1, L2, L3, L4
IND, 0.25µH
WÜRTH ELEKTRONIK 744301025
6
dc2142af
DEMO MANUAL DC2142A
Parts List
ITEM
QTY
15
4
REFERENCE
PART DESCRIPTION
MANUFACTURER/PART NUMBER
Q1, Q5, Q10, Q15
XSTR, POWER MOSFET
INFINEON BSC050NE2LS
16
4
Q3, Q7, Q13, Q17
XSTR, POWER MOSFET
INFINEON BSC010NE2LSI
17
1
Q19
XSTR, N-CHANNEL DMOS FET
FAIRCHILD 2N7002A
18
2
Q20, Q21
XSTR, MOSFET, N-CHANNEL 30V
VISHAY SUD50N04-8M8P-4GE3
19
1
R1
RES, 0603, 20kΩ, 5%, 1/10W
VISHAY CRCW060320K0JNEA
20
1
R2
RES, 0603, 3.01kΩ, 1%, 1/10W
VISHAY CRCW06033K01FKEA
21
1
R3
RES, 0603, 1kΩ, 5%, 1/10W
VISHAY CRCW06031K00JNEA
22
3
R4, R51, R85
RES, 0603, 2.2Ω, 5%, 1/10W
VISHAY CRCW06032R20JNEA
23
2
R6, R14
RES, 0603, 10Ω, 1%, 1/10W
VISHAY CRCW060310R0FKEA
24
4
R8, R28, R58, R66
RES, 0603, 715Ω, 1%, 1/10W
VISHAY CRCW0603715RFKEA
25
2
R9, R27
RES, 0603, 3.57kΩ, 1%, 1/10W
VISHAY CRCW06033K57FKEA
26
13
R10, R13, R24, R50, R53, R54, R56,
R57, R59, R60, R61, R65, R67
RES, 0603, 0Ω, JUMPER
VISHAY CRCW06030000Z0EA
27
1
R12
RES, 0603, 13.3kΩ, 1%, 1/10W
VISHAY CRCW060313K3FKEA
28
1
R17
RES, 0603, 20kΩ, 1%, 1/10W
VISHAY CRCW060320K0FKEA
29
1
R21
RES, 0603, 4.02kΩ, 1%, 1/10W
VISHAY CRCW06034K02FKEA
30
3
R33, R42, R69
RES, 0603, 100kΩ, 1%, 1/10W
VISHAY CRCW0603100KFKEA
31
1
R45
RES, 0603, 5kΩ, 5%, 1/10W
VISHAY CRCW06035K00JNED
32
2
R46, R47
RES, 0603, 10kΩ, 1%, 1/10W
VISHAY CRCW060310K0FKEA
33
1
R63
RES, 0603, 75kΩ 5% 1/10W
VISHAY CRCW060375K0JNEA
34
1
R102
RES, 0603, 237kΩ, 1%, 1/10W
VISHAY CRCW0603237KFKEA
35
1
SW1
SWITCH, SUBMINATURE SLIDE
C&K JS202011CQN
36
1
U1
IC, DUAL, 2-PHASE, SYNCHRONOUS
REGULATORS
LINEAR TECH. LTC3875EUJ#PBF-ES
37
1
U2
IC, POLYPHASE STEP-DOWN
SYNCHRONOUS SLAVE CONTROLLER
LINEAR TECH. LTC3874IUFD#PBF
CAP, 1210 OPTION
OPTION
Additional Demo Board Circuit Components
1
0
COUT27, COUT28, COUT29, COUT30,
COUT31, COUT32, COUT33, COUT34,
COUT35, COUT36, COUT37, COUT38,
COUT39, COUT40, COUT41, COUT42,
COUT43, COUT44, COUT45, COUT46
2
0
C9, C11, C26, C27, C28
CAP, 0603 OPTION
OPTION
3
4
C43, C44, C47, COUT21,
CAP, 0603, 1µF, 20%, 25V X5R
AVX 06033D105KAT2A
4
1
C37
CAP, 0805, 10µF, 10%, 16V X5R
MURATA GRM21BR61C106KE15L
5
1
C38
CAP, 0805, 22µF, 10%, 10V X5R
TDK C2012X5R1A226K
6
1
C42
CAP, 0603, 150pF, 5%, 50V NPO
AVX 06035A151JAT2A
7
2
C41, C45
CAP, 0603, 0.1µF, 10%, 25V X5R
AVX 06033C104KAT2A
8
1
C48
CAP, 0603, 22pF, 2%, 50V C0G
MURATA GRM1885C1H220GA01D
9
1
D5
DIODE, SCHOTTKY 30V, 100mA
CENTRAL SEMI CMDSH-3-TR
10
1
L5
IND, 3.3µH
WÜRTH ELEKTRONIK 744043003
dc2142af
7
DEMO MANUAL DC2142A
Parts List
ITEM
QTY
REFERENCE
PART DESCRIPTION
MANUFACTURER/PART NUMBER
11
0
Q2, Q4, Q6, Q8, Q11, Q14, Q16, Q18
XSTR, POWER MOSFET OPTION
OPTION
12
2
R88, R92
RES, 0603, 20kΩ, 5% 1/10W
VISHAY CRCW060320K0JNEA
13
2
R68, R87
RES, 0603, 0Ω, JUMPER
VISHAY CRCW06030000Z0EA
14
0
RN1, RN2
THERMISTOR, OPTION
OPTION
15
0
R5, R7, R11, R15, R16, R18, R19,
R34, R35, R37, R39, R40, R41, R43,
R44, R48,R49, R52, R55, R62, R64,
R70, R76, R101, R104, R105
RES, 0603 OPTION
OPTION
16
2
R77, R94
RES, 0603, 10kΩ, 1% 1/10W
VISHAY CRCW060310K0FKEA
17
1
R80
RES, 0603, 187kΩ, 1% 1/10W
VISHAY CRCW0603187KFKEA
18
1
R83
RES, 0603, 23.2kΩ, 1% 1/10W
VISHAY CRCW060323K2FKEA
19
1
R89
RES, 0603, 3.3Ω, 1%, 1/10W
VISHAY CRCW06033R30FNEA
20
1
R90
RES, 0603, 154kΩ, 1% 1/10W
VISHAY CRCW0603154KFKEA
21
1
R91
RES, 0603, 1MΩ, 5% 1/10W
VISHAY CRCW06031M00JNEA
22
1
R93
RES, 0603, 681kΩ, 1% 1/10W
VISHAY CRCW0603681KFEA
23
2
R95, R100
RES, 0603, 301Ω, 1% 1/10W
VISHAY CRCW0603301RFKEA
24
1
R96
RES, 0603, 82.5Ω, 5% 1/10W
VISHAY CRCW060382R5FKEA
25
2
R97, R98
RES, 2512, 0.01Ω, 1% 1W
VISHAY WSL2512R0100FEA
26
1
R99
RES, VARIABLE 5k
BOURNS 3386P-1-502-LF
27
1
UD1
IC, OSCILLATOR WITH SPREAD SPECTRUM
MODULATION
LINEAR TECH. LTC6908S6-1#PBF
28
1
U3
IC, 17V, 1A, SYNCHRONOUS STEP-DOWN
REGULATOR
LINEAR TECH. LTC3621EDCB-2#PBF
29
1
U4
IC, VOLTAGE-CONTROLLED PULSE WIDTH
MODULATOR
LINEAR TECH. LTC6992IS6-1
30
1
U5
IC, SINGLE OP AMP
LINEAR TECH. LT1803IS5
MILL MAX 2501-2-00-80-00-00-07-0
Hardware: For Demo Board Only
1
12
E1, E2, E3, E4, E5, E6, E7, E11, E13,
E14, E15, E16
TURRET
2
1
JP1
HEADER, 4-PIN
WURTH 620 004 111 21
3
2
JP6, JP7
HEADER, SINGLE ROW 3-PIN
WURTH 620 003 111 21
4
6
J1, J2, J3, J4, J5, J6
STUD, TEST PIN
PEM KFH-032-10
J7, J9
5
2
6
6
7
4
MH1, MH2, MH3, MH4
CONN, BNC, 5-PINS
CONNEX 112404
LUG RING, #10
KEYSTONE 8205
STANDOFF, SNAP ON
KEYSTONE 8834
8
12
NUT, BRASS 10-32
ANY #10-32
9
6
WASHER, #10 TIN PLATED BRASS
ANY #10 EXT BZ TN
10
3
SHUNT
WURTH 608 002 134 21
8
JP1, JP6, JP7
dc2142af
J1
OPT
RN1
ITH
VO_SNS-
VFB
VO_SNS+
TK/SS
TK/SS
RUN
RUN
VIN-
GND
J2
4.5V - 14V
VIN
VIN+
RUN
TK/SS
R40
OPT
0
OPT
R44
+ C1
270uF
16V
R10
VO_SNS-
VFB
E6
E5
E4
E2
OPT
C26
R11
OPT
0.1uF
C7
R4 2.2
+ C2
270uF
16V
VIN
OPT
RN2
RUN
5
ON
OPT
R48
C16
2.2nF
OPT
C27
2
OPT
R7
OPT
C28
VIN
R45
5k
MODE
BM CCM
4
C5 10nF
OPT
R5
PS
2
1
JP1
3
R1
20K
SW1
OPT
C11
C9
OPT
OFF
R43
OPT
4.02k 1%
R21
C15 220pF
R17
20k
1%
R12
13.3k
1%
C3
1.0uF
4
1
6
3
PLLIN
2
1
R46
10K
1%
36
14
13
12
37
16
8
7
6
5
4
3
2
1
34
R47
10K
1%
R33
100k
1%
TRSET1
TRSET2
TAVG
TCOMP2
TCOMP1
RUN2
TKSS2
VOSNS2-
VOSNS2+
ITH2
ITH1
VOSNS1-
VOSNS1+
TK/SS1
RUN1
4.7uF
EXTVCC
R3 1k
INTVCC1
4.7uF
C4
C46
26
VIN
LTC3875EUJ
U1
R41
OPT
R2
3.01k
1%
INTVCC1
OPT
R19
INTVCC1
R37
OPT
ISNS2-
SNSA2+
SNSD2+
BG2
BOOST2
SW2
TG2
SNS1-
SNSD1+
SNSA1+
BG1
BOOST1
SW1
TG1
BST2
BG2
22
23
10
9
R39
OPT
C20
220nF
SW2
11
TG2
20
C12
220nF
21
39
38
40
27 BG1
28 BST1
30 SW1
29 TG1
OPT
R105
220nF
C24
R18
OPT
R13 0
R34
OPT
R24
0
220nF
C10
INTVCC1
4
Q6
OPT
Q4
OPT
4
Q8
OPT
4
CUSTOMER NOTICE
Q7
BSC010NE2LSI
4
4
Q2
OPT
5
CIN1
10uF
1210
CIN3
10uF
1210
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
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.
R35
OPT
CMDSH-3-TR
0.1uF D2
C18
4
VIN
Q3
BSC010NE2LSI
4
Q5
BSC050NE2LS
OPT
R16
INTVCC1
R15
OPT
CMDSH-3-TR
0.1uF D1
C8
4
Q1
BSC050NE2LS
VIN
5
1
2
3
INTVCC1
17
32
PHASMD
5
1
2
3
E1
2
1
24
EXTVCC
IFAST
25
INTVCC
FREQ
15
35
ILIM
SGND/PGND
41
33
MODE/PLLIN
ENTMPB
18
31
CLKOUT
PGOOD
19
5
1
2
3
5
1
2
3
5
1
2
3
5
1
2
3
1
2
3
5
1
2
3
EXTCLK
L1
0.25uH
R28
715
1%
!"
SCALE = NONE
COUT6
100uF
6.3V
1210
VO_SNS-
COUT2
100uF
6.3V
1210
C25
1.0uF
EXTVCC
COUT5
+ 330uF
6.3V
7343
R14
10
1%
COUT3
+ 330uF
6.3V
7343
DATE
E14
12/31/13
DATE:
N/A
SIZE
GND
EXTVCC
GND
PGOOD
PGOOD
E13
E11
J6
SHEET 1
LTC3875EUJ / LTC3874EUFD
DEMO CIRCUIT 2142A
Tuesday, December 31, 2013
IC NO.
VOUT
VO_SNS-
GND
VOUT
VO_SNS+
1.0V AT 120A
J5
E7
J4
J3
E3
CLKOUT
Y INGY I, Y .
APPROVED
3
OF 3
REV.
1630 McCarthy Blvd.
Milpitas, CA 95035
Phone: (408)432-1900 www.linear.com
Fax: (408)434-0507
LTC Confidential-For Customer Use Only
COUT8
+ 330uF
6.3V
7343
COUT4
+ 330uF
6.3V
7343
TECHNOLOGY
R42
100k
1%
INTVCC1
COUT7
100uF
6.3V
1210
VOUT
COUT1
100uF
6.3V
1210
VOUT
VO_SNS+
R6
10
1%
REVISION HISTORY
PROD
DESCRIPTION
TITLE: SCHEMATIC
HIGH EFFICIENCY POLYPHASE , SYNCHRONOUS
BUCK CONVERTER WITH VERY LOW DCR INDUCTOR
744301025
DCR=0.32m OHM
L2
R9
3.57k
1%
APP ENG. #"$%#"&#'
PCB DES.
0.25uH
3
REV
744301025
DCR=0.32m OHM
APPROVALS
R27
3.57k
1%
CIN4
10uF
1210
R8
715
1%
CIN2
10uF
1210
ECO
DEMO MANUAL DC2142A
Schematic Diagram
dc2142af
9
TK/SS
R49
R53
0
OPT
R55
R52
OPT
INTVCC2
R54
0
INTVCC2
R56 0
OPT
R50 0
COUT17
COUT18
+ 330uF
+ 330uF
6.3V
6.3V
7343
7343
VOUT
R67
0
INTVCC2
OPT
R64
PGOOD
ITH
RUN
PGOOD
CLKOUT
EXTCLK
COUT19
100uF
6.3V
1210
0
COUT20
100uF
6.3V
1210
R63 75k
100pF
C34
R61
R60 0
R57 0
13
11
10
27
9
28
5
4
8
1
12
COUT21
1.0uF
PHASMD
ILIM
FREQ
LOWDCR
ITH1
ITH0
RUN1
RUN0
MODE1
MODE0
SY NC
1.0uF
20
U2
4.7uF
C30
C39
100uF
6.3V
1210
Q19
2N7002A
BST3
BG3
22
21
BST4
BG4
16
17
3
0
25
26
6
COUT25
100uF
6.3V
1210
COUT24
100uF
6.3V
1210
R69
100k
1%
INTVCC2
C35
220nF
SW4
15
7
TG4
14
3
C33
220nF
SW3
23
2
TG3
24
R68
FAULT1B
FAULT0B
ISENSE1-
ISENSE1+
BG1
BOOST1
SW1
TG1
ISENSE0-
ISENSE0+
BG0
COUT22
COUT23
+ 330uF
+ 330uF
6.3V
6.3V
7343
7343
2
SW0
TG0
BOOST0
4.7uF
C31
LTC3874IUFD#PBF
R51
2.2
C40
100uF
6.3V
1210
VIN
EXTVCC
18
EXTVCC
C29
19
INTVCC
GND
29
R59 0
R65
0
4
Q16
OPT
Q14
OPT
4
Q18
OPT
4
CIN6
10uF
1210
CIN7
10uF
1210
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
CUSTOMER NOTICE
Q17
BSC010NE2LSI
4
4
Q11
OPT
5
CIN8
10uF
1210
CIN5
10uF
1210
LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A
CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS;
HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO
VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL
APPLICATION. COMPONENT SUBSTITUTION AND PRINTED
CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT
PERFORMANCE OR RELIABILITY. CONTACT LINEAR
TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
INTVCC2
4
VIN
Q13
BSC010NE2LSI
4
Q15
BSC050NE2LS
CMDSH-3-TR
0.1uF D4
C36
CMDSH-3-TR
INTVCC2
0.1uF D3
C32
4
Q10
BSC050NE2LS
VIN
5
INTVCC2
1
5
5
1
2
3
5
1
2
3
5
1
2
3
1
2
3
5
1
2
3
1
2
3
1
2
3
5
10
1
2
3
VIN
L3
0.25uH
0.25uH
OPT
OPT
!"
SCALE = NONE
APP ENG. #"$%&"'#(
PCB DES.
APPROVALS
R70
R66
715
1%
744301025
L4
R62
R58
715
1%
744301025
COUT15
+ 330uF
6.3V
7343
COUT10
+ 330uF
6.3V
7343
TECHNOLOGY
COUT14
100uF
6.3V
1210
COUT9
100uF
6.3V
1210
VOUT
DATE:
N/A
SIZE
SHEET 2
LTC3875EUJ / LTC3874EUFD
DEMO CIRCUIT 2142A
Wednesday, March 05, 2014
IC NO.
2
OF 3
REV.
1630 McCarthy Blvd.
Milpitas, CA 95035
Phone: (408)432-1900 www.linear.com
Fax: (408)434-0507
LTC Confidential-For Customer Use Only
COUT16
+ 330uF
6.3V
7343
COUT11
+ 330uF
6.3V
7343
TITLE: SCHEMATIC
HIGH EFFICIENCY POLYPHASE , SYNCHRONOUS
BUCK CONVERTER WITH VERY LOW DCR INDUCTOR
COUT13
100uF
6.3V
1210
COUT12
100uF
6.3V
1210
DEMO MANUAL DC2142A
Schematic Diagram
dc2142af
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 representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
ON
R92
20K
1
OPT
R104
154k
2
0.1uF
3
2
1
R77
10K
1%
C45
OFF3
R90
BIAS
JP6
C37
10uF
16V
0805
INTVCC1
VIN
D5
2
6
5
SET
GND
MOD
DIV
V+
OUT
4
5
6
VIN
MODE
INTVCC
U4 LTC6992IS6-1
C47
1.0uF
25V
R102
237k
1%
R93
681K
1%
R91
R87
1M
0
RUN
FB
SW
L5
3.3uH
C43
1.0uF
R100
301
1%
R95
301
1%
0.1uF
R101
OPT
R88
20K
C41
744043003
+5.5V
R99
5K
3
4
1
UD1 LTC6908S6-1#PBF
1
6
V+
OUT1
2
5
GND
OUT2
3
4
SET
MOD
70Hz, 3% Duty Cy cle
CMDSH-3-TR
GND
7
+5.5V
U3
LTC3621EDCB-2
OPTIONAL 5.5V BIAS
R83
23.2K
1%
R80
187k
1%
+IN
V-
V+
-IN
VOUT
U5 LT1803IS5
EXTCLK
3
2
5
C48
22pF
4
1
C38
22uF
10V
0805
EXTVCC
82.5 1%
R96
COUT27
OPT
1210
COUT38
OPT
1210
COUT28
OPT
1210
COUT39
OPT
1210
COUT29
OPT
1210
R98
0.01
2512
SUD50N04-8M8P-4GE3
Q20
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
CUSTOMER NOTICE
R97
0.01
2512
Q21
2
J9
2
J7
!"
SCALE = NONE
APP ENG. #"$%&"'#(
PCB DES.
COUT43
OPT
1210
DATE:
N/A
SIZE
SHEET 3
LTC3875EUJ / LTC3874EUFD
DEMO CIRCUIT 2142A
Wednesday, March 05, 2014
IC NO.
2
OF 3
REV.
1630 McCarthy Blvd.
Milpitas, CA 95035
Phone: (408)432-1900 www.linear.com
Fax: (408)434-0507
LTC Confidential-For Customer Use Only
TITLE: SCHEMATIC
HIGH EFFICIENCY POLYPHASE , SYNCHRONOUS
BUCK CONVERTER WITH VERY LOW DCR INDUCTOR
TECHNOLOGY
COUT36
OPT
1210
COUT46
OPT
1210
COUT35
OPT
1210
COUT45
OPT
1210
COUT34
OPT
1210
COUT44
OPT
1210
COUT33
OPT
1210
VOUT
IOUT STEP
VOUT
COUT42
OPT
1210
COUT32
OPT
1210
APPROVALS
GND
C44
1.0uF
1
1
COUT41
OPT
1210
COUT31
OPT
1210
E16
VOUT
COUT40
OPT
1210
COUT30
OPT
1210
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.
R85
2.2
SUD50N04-8M8P-4GE3
DYNAMIC LOAD CIRCUIT
COUT37
OPT
1210
VOUT
EXT PULSE
E15
R94
10K
1%
INT EXT
JP7
PULSE
2
3.3 1% 1
3
OPT
R76
C42
150pF
R89
+5.5V
VOUT
DEMO MANUAL DC2142A
Schematic Diagram
dc2142af
11
DEMO MANUAL DC2142A
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
12 Linear Technology Corporation
dc2142af
LT 0314 • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900
●
FAX: (408) 434-0507 ● www.linear.com
 LINEAR TECHNOLOGY CORPORATION 2014
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