DC1755A - Demo Manual

DEMO MANUAL DC1755A
LTC3860EUH
Wide Input Range,
High Efficiency Step-Down
DC/DC Converter
DESCRIPTION
Demonstration circuit DC1755A provides the user with
two high current dual phase synchronous buck converters
driven by the LTC3860. These buck converters provide
outputs of 1.5V/50A and 1.2V/50A over an input voltage
range of 6V to 14V and a switching frequency of 500kHz.
The board can be easily modified for a 4-phase, single VO,
100A supply. The power stage for each phase consists
of the tri-state PWM compatible 6mm × 6mm Fairchild
DrMOS module and a 0.47μH 13.2mm × 12.8mm iron
powder type inductor from Würth. A high density, two
sided drop-in layout is used. The entire converter, excluding
the bulk output and input capacitors, fits within a 2.25” ×
1.38” area on the board.
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. All other trademarks are the property of their respective owners.
PERFORMANCE SUMMARY
PARAMETER
The main features of the board are listed below:
• High efficiency and high current density.
• Remote sensing for each output.
• Optional resistors to tie the two outputs together.
• Connector and header to tie two or more boards together
for up to 12-phase operation.
• RUN, PGOOD and TRACK/SS pins for each output.
• CLKIN and CLKOUT pins.
• Onboard bias voltage regulator.
• BNC connectors to monitor each output voltage.
Design files for this circuit board are available at
http://www.linear.com/demo
(TA = 25°C), no airflow.
CONDITIONS
VALUE
Minimum Input Voltage
6V
Maximum Input Voltage
14V
Output Voltage VOUTA
IOUTA = 0A to 50A, VIN = 6V to 14V
1.5V ± 2%
Output Voltage VOUTB
IOUTB = 0A to 50A, VIN = 6V to 14V
1.2V ± 2%
VOUTA Maximum Output Current, IOUTA
VIN = 6V to 14V, VOUTA = 1.5V
50A
VOUTB Maximum Output Current, IOUTB
VIN = 6V to 14V, VOUTB = 1.2V
Nominal Switching Frequency
50A
500kHz
Efficiency
VOUTA = 1.5V, IOUTA = 50A, VIN = 12V
90.2% Typical
See Figures 2 and 3
VOUTB = 1.2V, IOUTB = 50A, VIN = 12V
89.2% Typical
dc1755af
1
DEMO MANUAL DC1755A
QUICK START PROCEDURE
Demonstration circuit 1755A is easy to set up to evaluate the performance of the LTC3860EUH. Please refer to
Figure 1 for proper measurement equipment setup and
follow the procedure below.
1) With power off, connect the input supply, load and
meters as shown in Figure 1. Preset the load to 0A and
VIN supply to be 0V. Place jumpers in the following
positions:
JP1
JP2
JP3
RUNA
RUNB
INT PWR BLK BIAS
ON
ON
ON
2) Adjust the input voltage to be between 6V to 14V. VOUTA
should 1.5V ± 2%.
Note 3. Do not apply the load from the VOSA+ turret to
the VOSA– turret or from the VOSB+ turret to the VOSB–
turret. These turrets are only intended to monitor the
voltage across COUT3 and COUT13 respectively. Heavy
load currents applied across these turrets may damage
the converter.
DYNAMIC LOAD CIRCUIT (OPTIONAL)
Demonstration circuit 1755A provides a simple load step
circuit consisting of a MOSFET and sense resistor for each
rail. To apply a load step, follow the steps below.
1) Preset the amplitude of a pulse generator to 0.0V and
the duty cycle to 5% or less.
3) Next, apply 50A load to each output and remeasure
VOUT.
2) Connect the scope to the VOUT BNC connectors for
the rail under test with a coax cable. To monitor the
load step current, connect the scope probe across the
ISTEP+– turrets for that rail.
4) Once the DC regulation is confirmed, observe the output
voltage ripple, load step response, efficiency and other
parameters.
3) Connect the output of the pulse generator to the PULSE
GEN turret for the rail under test and connect the return
to one of the GND turrets.
Note 1. No airflow is required at room temperature with
50A on both outputs. But for ambient temperatures higher
than 30°C, a cooling fan is recommended.
4) With the converter running, slowly increase the
amplitude of the pulse generator output to provide the
desired load step pulse height. The scaling for the load
step signal is 10mV/A.
VOUTB should 1.2V ± 2%.
Note 2. Use the BNC connectors labeled VOUTA or VOUTB
to measure the output voltage ripple.
dc1755af
2
DEMO MANUAL DC1755A
QUICK START PROCEDURE
+
IOUTA
-
VOUTA
load
-
VOUTB
load
A
+
IOUTB
A
+
VOUTA
*
+
V
V
-
VOUTB
-
*
+
V
VIN
-
DC1755a F01
IIN
*
A
+
VIN
supply
Monitor voltage across COUT7
and COUT19 for accurate
efficiency measurements.
-
Figure 1. Proper Measurement Equipment Setup
dc1755af
3
DEMO MANUAL DC1755A
95
95
90
90
EFFICIENCY (%)
EFFICIENCY (%)
QUICK START PROCEDURE
85
80
80
VIN = 6V
VIN = 10V
VIN = 12V
VIN = 14V
75
0
10
20
30
40
50
85
VIN = 6V
VIN = 10V
VIN = 12V
VIN = 14V
75
60
0
10
20
LOAD CURRENT (A)
30
40
50
DC1755a F02
Figure 2. Efficiency Curves for the 1.5V Rail of the DC1755A
1.5VO (AC)
50mV/DIV
77mV
DC1755a F03
Figure 3. Efficiency Curves for the 1.2V Rail of the DC1755A
1.2VO (AC)
50mV/DIV
81mV
50A
LOAD STEP
10A/DIV
60
LOAD CURRENT (A)
50A
LOAD STEP
10A/DIV
25A
20μs/DIV
DC1755a F04
Figure 4. Load Step Response of the 1.5V Rail
SINGLE OUTPUT/4-PHASE OPERATION
A single output/4-phase converter may be preferred for
higher output current applications. The optional components required to tie the phases together are found on
sheet 3 of the schematic in the lower right hand corner. To tie
the two outputs together, make the following modifications:
1) Select one rail to be the master.
a) If VOUTA is the master, then stuff 0Ω at R103 to
disable the error amplifier for VOUTB.
b) If VOUTB is the master, then stuff 0Ω at R104 to
disable the error amplifier for VOUTA.
25A
20μs/DIV
DC1755a F05
Figure 5. Load Step Response of the 1.2V Rail
2) Stuff 0Ω at R87, R88, R89 and R91 to tie the IAVG,
COMP, TRACK/SS and RUN signals together.
3) Remove the redundant compensation components.
6-PHASE AND 12-PHASE OPERATION
Two or more boards may be tied together for up to 12-phase
operation. To parallel two or more boards, place the boards
side by side. Connect J9 of one board to J10 of the adjacent board (see sheet 3 of the schematic, lower right
hand corner). This will tie the IAVG, COMP, TRACK/SS and
dc1755af
4
DEMO MANUAL DC1755A
QUICK START PROCEDURE
RUN signals of the adjacent boards together. Next, locate
the exposed copper shapes on the four corners of the
board on the top and bottom layers. Use these shapes to
tie the VOUT, VIN and GND planes of the adjacent boards.
Next, select which phases will be the master or the slave.
Figure 6 shows the typical setup for a 6-phase + 2-phase
converter. Figure 7 shows the typical setup for a 12-phase
converter. For additional help and support, contact your
local LTC sales office.
TOP
6 PHASE
CONVERTER
Cu
Cu
BOARD #1
BOARD #2
BOARD #1 = MASTER
R87, R88, R89, R91 = 0
R101, R102 = 0.0m
R103 = 0
R104 = NOT STUFFED
2 PHASE
CONVERTER
BOARD #2
BOARD #2
SIDE A = SLAVE
SIDE B = INDEPENDENT DUAL PHASE RAIL
R87, R88, R89, R91 = NOT STUFFED
R101, R102 = NOT STUFFED
R103 = NOT STUFFED
R104 = 0
6 PHASE
CONVERTER
GND
BOTTOM
Cu BOARD #1
GND
Cu
DC1755a F06
Figure 6. Typical Setup for a 6-Phase + 2-Phase Converter
dc1755af
5
DEMO MANUAL DC1755A
QUICK START PROCEDURE
TOP
Cu
Cu
Cu
BOARD #1
Cu
BOARD #2
BOARD #1 = MASTER
R87, R88, R89, R91 = 0
R101, R102 = 0.0m
R103 = 0
R104 = NOT STUFFED
BOARD #3
BOARD #2 = SLAVE
R87, R88, R89, R91 = 0
R101, R102 = 0.0m
R103, R104 = 0
BOARD #3 = SLAVE
R87, R88, R89, R91 = 0
R101, R102 = 0.0m
R103, R104 = 0
BOTTOM
BOARD #3
GND
Cu BOARD #2
Cu
GND
Cu BOARD #1
GND
Cu
DC1755a F07
Figure 7. Typical Setup for a 12-Phase Converter
dc1755af
6
DEMO MANUAL DC1755A
PARTS LIST
ITEM
QTY
REFERENCE
PART DESCRIPTION
MANUFACTURER/PART NUMBER
Required Circuit Components
1
1
CIN1
CAP, 180μF 20% 16V OSCON
SANYO 16SVP180MX
2
4
CIN3, CIN5, CIN7, CIN9
CAP, 1210 22μF 20% 16V X5R
TDK C3225X5R1C226M
3
12
COUT1 to COUT3, COUT4 to COUT6,
COUT11 to COUT13, COUT14 to COUT16
CAP, 7343 330μF 20% 2.5V POSCAP
SANYO 2R5TPE330M9L
4
8
COUT7 to COUT10, COUT17 to COUT20
CAP, 1206 100μF 20% 6.3V X5R
MURATA GRM31CR60J107ME39L
5
2
C1 to A, C1 to B
CAP, 0603 470pF 10% 25V NPO
AVX 06033A471KAT2A
6
8
C1, C8, C9, C10, C13, C20, C21, C22
CAP, 0603 0.22μF 10% 25V X7R
TDK C1608X7R1E224K
7
8
C2, C11, C14, C23, C31, C32, C33, C34
CAP, 0603 2.2μF 10% 16V X7R
MURATA GRM188R61C225KE15
8
2
C4, C16
CAP, 0603 100pF 5% 25V NPO
AVX 06033A101JAT2A
9
2
C2 to A, C2 to B
CAP, 0603 68pF 5% 25V NPO
AVX 06033A680JAT2A
10
2
C3 to A, C3 to B
CAP, 0603 2200pF 25V X7R
MURATA GRM188R71E222MA01
11
3
C7, C19, C28
CAP, 0603 1μF 20% 25V X5R
AVX 06033D105MAT2A
12
4
L1, L2, L3, L4
IND, 0.47μH 20%
WÜRTH 744355147
13
1
RB to A
RES, 0603 13.3k 1% 1/10W
VISHAY CRCW060313K3FKEA
14
1
RB to B
RES, 0603 20k 1% 1/10W
NIC NRC06F2002TRF
15
19
R1, R11, R12, R16, R20, R25, R36, R45, R46,
R50, R54, R55, R59, R62, R69, R112, R113,
R116, R118
RES, 0603 0Ω JUMPER
VISHAY CRCW06030000Z0EA
16
2
R1 to A, R1 to B
RES, 0603 20k 1% 1/10W
NIC NRC06F2002TRF
17
6
R2, R17, R37, R51, R57, R107
RES, 0603 1Ω 5% 1/10W
VISHAY CRCW06031R00JNEA
18
2
R2 to A, R2 to B
RES, 0603 6.8k 1% 1/10W
VISHAY CRCW06036K80FKEA
19
2
R3 to A, R3 to B
RES, 0603 523Ω 1% 1/10W
VISHAY CRCW0603523RFKEA
20
9
R3, R4, R24, R26, R31, R38, R39, R61, R63
RES, 0603 10k 1% 1/10W
VISHAY CRCW060310K0FKEA
21
2
R8, R43
RES, 0603 100k 5% 1/10W
YAGEO RC0603JR-07100KL
22
4
R15, R33, R49, R70
RES, 0603 2.87k 1% 1/10W
VISHAY CRCW06032K87FKEA
23
2
R18, R52
RES, 0603 59.0k 1% 1/10W
VISHAY CRCW060359K0FKEA
24
4
R19, R21, R53, R56
RES, 0603 10Ω 1% 1/10W
NIC NRC06F10R0TRF
25
2
R30, R67
RES, 0603 40.2k 1% 1/10W
VISHAY CRCW060340K2FKEA
26
2
U1, U2
IC, DUAL OUTPUT BUCK CONVERTER
LINEAR TECHNOLOGY LTC3860EUH
27
4
U3, U4, U5, U6
INTEGRATED MOSFET, DC/DC CONVERTER
FAIRCHILD FDMF6707B
Bias Supply and UVLO Circuit
1
1
C29
CAP, 0603 2.2μF 10% 16V X7R
MURATA GRM188R61C225KE15
2
1
C25
CAP, 0603 1μF 20% 25V X5R
AVX 06033D105MAT2A
3
1
C26
CAP, 0805 10μF 10% 25V NPO
AVX 08053D106MAT2A
4
1
C27
CAP, 0603 0.1μF 10% 16V X7R
AVX 0603YC104KAT2A
5
1
C30
CAP, 0603 10pF 5% 50V NPO
MURATA GQM1885C1H100JB01
6
1
D1
DIODE, BAV170 SOT23
DIODES INC., BAV170
7
1
D2
DIODE SHOTTKY SOD326
NXP PMEG2005AEA
8
1
L5
INDUCTOR 27μH 20%
WÜRTH 7447789127
9
1
R105
RES, 0603 20k 1% 1/10W
NIC NRC06F2002TRF
10
1
R106
RES, 0603 10k 1% 1/10W
VISHAY CRCW060310K0FKEA
dc1755af
7
DEMO MANUAL DC1755A
PARTS LIST
ITEM
QTY
REFERENCE
PART DESCRIPTION
MANUFACTURER/PART NUMBER
11
1
R90
RES, 1206 0Ω JUMPER
VISHAY CRCW12060000Z0EA
12
1
R93
RES, 0603 100Ω 5% 1/10W
VISHAY CRCW0603100RFKEA
13
1
R97
RES, 0603 105k 1% 1/10W
VISHAY CRCW0603105KFKEA
14
1
R100
RES, 0603 127k 1% 1/10W
VISHAY CRCW0603127KFKEA
15
1
U7
IC, STEP DOWN REGULATOR, DFN
LINEAR TECHNOLOGY LT3502EDC
16
1
U8
IC, VOLTAGE MONITOR, DC-3
LINEAR TECHNOLOGY LT6703IDC-3
Additional Circuit Components
1
0
CIN2
CAP, SANYO SVP-F8
OPTIONAL
2
0
CIN4, CIN6, CIN8, CIN10 to CIN12
CAP, 1210
OPTIONAL
3
0
COUT21 to COUT26, COUT31 to COUT36
CAP, 7343H
OPTIONAL
4
0
COUT27 to COUT30, COUT37 to COUT48
CAP, 1206
OPTIONAL
5
0
RES, 0603
R5, R6, R7, R9, R10, R13, R14, R23, R27,
R28, R29, R32, R34, R35, R40, R41, R42, R44,
R47, R48, R58, R60, R64, R65, R66, R68, R71,
R72, R87, R88, R89, R91, R92, R94, R95, R96,
R103, R104, R108, R110, R111, R114, R115,
R117, R119
OPTIONAL
6
0
C3, C5, C6, C12, C15, C17, C18, C24
CAP, 0603
OPTIONAL
7
0
Q2, Q3
MOSFET, TO-252
OPTIONAL
8
0
R73, R74, R77, R78, R83, R84, R85, R86
RES, 0603
OPTIONAL
9
0
R80, R82, R101, R102
RES, 2010
OPTIONAL
10
2
Q1, Q4
MOSFET, TO-252
VISHAY SUD50N03-09P
11
2
R75, R76
RES, 0603 10k 1% 1/10W
VISHAY CRCW060310K0FKEA
12
2
R79, R81
RES, 2010 0.010Ω 2% 1W
IRC LRC-LRF2010LF-01-R010-F
KEYSTONE 8831
Hardware/Components (For Demo Board Only)
1
4
STANDOFF, SNAP ON
2
12
NUT, BRASS #10-32
ANY
3
6
RING, LUG #10
KEYSTONE 8205
4
6
WASHER, TIN, PLATED BRASS
ANY
5
24
E1 to E11, E14, E16, E17 to E27
TURRET
MILL MAX 2501-2-00-80-00-00-07-0
6
3
JP1 to JP3
HEADER, 3 PIN
SAMTEC TMM-103-02-L-S
7
3
XJP1 to XJP3
SHUNT, 2mm CTRS
SAMTEC 2SN-BK-G
8
6
J1 to J4, J11, J12
STUD, TEST PIN
PEM KFH-032-10
9
2
J7, J8
CON, BNC, 5 PINS
CONNEX 112404
10
1
J9
HEADER, DOUBLE ROW, RIGHT ANGLE
MILL-MAX 802-40-008-20-001000
11
1
J10
SOCKET, DOUBLE ROW
MILL-MAX 803-43-008-20-001000
dc1755af
8
1
2
3
4
RB-A
13.3K
1%
3
E9
R32
OPT
CLKINA
R31
10k
VCCA
VCCA
R110
OPT
R29
OPT
8
7
6
5
4
3
2
1
VCCA
FB2
COMP2
VSNSP
VSNSN
VSNSOUT
COMP1
FB1
C12
OPT
VIN
R11
0
TRACK/SSA
VCC
C5
OPT
VCCA
R8
100K
R34
OPT
R30
40.2K
VCCA
C6
OPT
A
IAVGA
R7
OPT
U1
LTC3860EUH
CLKOUTA
FSWITCH = 500kHz
TYPICAL
VDIFA
FBA
C7
1uF
R17
1
R14
OPT
COMPA
R2-A
6.8k
C1-A
470pF
R117
OPT
E7
R12
0
VOB+
R10
OPT
C3
OPT
5VBIAS
R116
0
VOSA+
68pF
C2-A
R3-A
523
C3-A
2200pF
E4
E3
JP1
2
CAPACITORS AND RESISTORS ARE 0603
UNLESS OTHERWISE SPECIFIED.
GND
CLKINA
VOSA-
R1-A
20K
1%
R112
0
VDIFA
TRACK/SSA
PGOODA
OFF
ON
GND
33
31
VINSNS
32
TRK/SS1
30
CLKIN
11
TRK/SS2
9
28
CLKOUT
12
FREQ
10
SGND
29
SGND
27
IAVG
R35
OPT
14
C4
100pF
PWMEN2
RUN2
ILIM2
ISNS2P
ISNS2N
ISNS1N
ISNS1P
ILIM1
RUN1
PWMEN1
R13
OPT
R9
OPT
VCCA
VIN
PWM1
25
PGOOD1
PGOOD2
26
PWMEN1
PWMEN2
15
PWM2
16
PHSMD
13
OPT
B
R25 0
17
18
19
20
21
22
23
24
R18
59.0k
R28
OPT
R23
OPT
VCCA
R16
0 ILIMA
B
CIN6
OPT
1210
CIN3
22uF
16V
1210
CIN5
22uF
16V
1210
C9
0.22uF
C8
0.22uF
CIN4
OPT
1210
VIN
20
19
18
17
16
15
14
13
12
11
20
19
18
17
16
15
14
13
12
11
PGND
PGND
PGND
PGND
PGND
VSWH
VIN
VIN
VIN
VIN
PGND
PGND
PGND
PGND
PGND
VSWH
VIN
VIN
VIN
VIN
VIN
PGND
0.22uF
C1
C10
0.22uF
C2
2.2uF
16V
R1 0
C
U3
FDMF6707B
C11
2.2uF
16V
R20 0
5VBIAS
1
5VBIAS
U4
FDMF6707B
C
PHASES 1 AND 2
22
R6
PGND
23
RUNA
PGND
A
21
PGND
22
10
9
42
8
21
7
PGND
24
3
1
26
PGND
6
GH
10
9
42
8
VIN
VIN
VIN
NC
PGND
23
PGND
6
PHASE
7
24
PGND
25
5
41
GH
PGND
25
4
DISB#
VSWH
VSWH
VSWH
VSWH
VSWH
GL
CGND
THWN
VSWH
VSWH
VSWH
VSWH
VSWH
GL
CGND
THWN
DISB#
PWM
31
32
33
34
35
36
37
38
39
40
DISBL#2
R26
10K
THDN2
THDN1
R5
OPT
R27
OPT
DISBL#1
R4
10K
CUSTOMER NOTICE
C32
2.2uF
16V
31
32
33
34
35
36
37
38
39
40
C31
2.2uF
16V
L1
0.47uH
744355147
WURTH EL.
D
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
+
AK
SCALE = NONE
MIKE S.
COUT4
330uF
2.5V
CIN11
OPT
1210
CIN2
OPT
R21
10
COUT3
330uF
2.5V
VOA+
R19
10
+
+
E8
E6
J4
COUT1
330uF
2.5V
J3
E5
DATE
09-28-11
GND
VOSA-
GND
VOUTA
1.5V / 50A
VIN-
GND
VIN
6V - 14V
VIN+
VOSA+
E2
J2
J1
E1
MIKE S
APPROVED
DATE:
N/A
SIZE
LTC3860EUH
E
DEMO CIRCUIT 1755A
Monday, January 16, 2012
IC NO.
SHEET 1
OF 3
2
REV.
DUAL OUTPUT 4 -PHASE STEP-DOWN CONVERTER
1630 McCarthy Blvd.
Milpitas, CA 95035
Phone: (408)432-1900 www.linear.com
Fax: (408)434-0507
LTC Confidential-For Customer Use Only
VOSA-
COUT2
330uF
2.5V
+
VIN
CIN1
180uF
16V
VOSA+
+
PRODUCTION
+
E
DESCRIPTION
REVISION HISTORY
TECHNOLOGY
COUT9
100uF
6.3V
1206
+
2
REV
TITLE: SCHEMATIC
COUT10
100uF
6.3V
1206
COUT5
330uF
2.5V
COUT6
330uF
2.5V
+
COUT7
100uF
6.3V
1206
CIN12
OPT
1210
__
ECO
COUT8
100uF
6.3V
1206
APPROVALS
0.47uH
744355147
WURTH EL.
L2
R33
2.87K
1%
R15
2.87K
1%
D
LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A
CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS;
HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO
PCB DES.
VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL
APP ENG.
APPLICATION. COMPONENT SUBSTITUTION AND PRINTED
CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT
PERFORMANCE OR RELIABILITY. CONTACT LINEAR
TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
R24 TP2
10K
1 R107
TP1
PWM
R3
10K
R2
CGND
GND
PGND
4
BOOT
PGND
27
VIN
VIN
VIN
NC
PHASE
5
41
CGND
GND
27
PGND
26
BOOT
PGND
28
VDRV
PGND
3
1
VCIN
2
VDRV
PGND
28
SMOD#
VSWH
VSWH
VSWH
VCIN
2
43
29
30
1
SMOD#
VSWH
VSWH
VSWH
43
29
30
RUNA
1
2
3
4
DEMO MANUAL DC1755A
SCHEMATIC DIAGRAM
dc1755af
9
1
2
3
4
RB-B
20.0K
1%
E11
GND
CLKOUTB
E16
E14
R68
OPT
VCCB
R59 0
R119
OPT
R118
0
R111
OPT
C1-B
470pF
R2-B
6.8k
C15
OPT
C24
OPT
R66
OPT
8
7
6
5
FB2
COMP2
VSNSP
VSNSN
VSNSOUT
COMP1
FB1
VCC
VIN
A
CLKOUTB
R45
0
U2
LTC3860EUH
R67
40.2K
VCCB
IAVGB
C18
OPT
RUNB
TRACK/SSB
R43
100K
VCCB
FSWITCH = 500kHz TYPICAL
VCCB
VDIFB
4
3
2
1
VCCB
C17
OPT
C19
1uF
FBB
R48
OPT
R51 1
R46
0
COMPB
5VBIAS
VOSB+
68pF
C2-B
R3-B
523
3
E10
JP2
C3-B
2200pF
R69 0
CLKOUTA
VOSB-
R1-B
20K
1%
R113
0
VDIFB
TRACK/SSB
PGOODB
OFF
2
31
1
32
TRK/SS1
R72
OPT
R71
OPT
VIN
ILIM1
RUN1
23
17
18
19
20
21
22
R62 0
R58
OPT
R54 0
PWMEN4
RUNB
RUN2
ILIM2
ISNS2P
ISNS2N
ISNS1N
ISNS1P
24
R50
0
R47
OPT
R44
OPT
VCCB
PWMEN3
100pF
C16
R42
OPT
R41 OPT
26
RUNB
33
GND
VINSNS
FREQ
10
CLKIN
11
TRK/SS2
9
30
SGND
28
IAVG
29
SGND
CLKOUT
12
PHSMD
13
25
PWM1
27
PGOOD1
PGOOD2
14
PWMEN1
PWMEN2
15
ON
B
B
R52
59.0k
R65
OPT
R60
OPT
VCCB
ILIMB
CIN10
OPT
1210
C21
0.22uF
C20
0.22uF
CIN8
OPT
1210
CIN9
22uF
16V
1210
CIN7
22uF
16V
1210
VIN
VIN
20
19
18
17
16
15
14
13
12
11
20
19
18
17
16
15
14
13
12
11
PGND
PGND
PGND
PGND
PGND
VSWH
VIN
VIN
VIN
VIN
PGND
PGND
PGND
PGND
PGND
VSWH
VIN
VIN
VIN
VIN
21
21
PWM2
16
0.22uF
C13
C
7
C14
2.2uF
16V
R36 0
U5
FDMF6707B
0.22uF
C22
C23
2.2uF
16V
0
R55
U6
FDMF6707B
PGND
5VBIAS
C
39
40
31
32
33
34
35
36
37
38
PWM
DISB#
DISBL#4
R63
10K
DISBL#3
R39
10K
THDN4
R64
OPT
THDN3
R40
OPT
CUSTOMER NOTICE
31
32
33
34
35
36
37
38
39
C34
2.2uF
16V
C33
2.2uF
16V
D
L3
D
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
+
SCALE = NONE
MIKE S.
AK
APPROVALS
0.47uH
744355147
WURTH EL.
L4
R70
2.87K
1%
R49
2.87K
1%
0.47uH
744355147
WURST EL.
LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A
CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS;
HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO
PCB DES.
VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL
APP ENG.
APPLICATION. COMPONENT SUBSTITUTION AND PRINTED
CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT
PERFORMANCE OR RELIABILITY. CONTACT LINEAR
TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
VSWH
VSWH
VSWH
VSWH
VSWH
GL
CGND
THWN
40
R61
10K TP4
VSWH
VSWH
VSWH
VSWH
VSWH
GL
CGND
THWN
DISB#
PWM
R38
10K TP3
1 R37
5VBIAS
1 R57
PHASES 3 AND 4
23
PGND
PHASE
10
9
42
8
VIN
VIN
VIN
NC
PGND
22
PGND
23
PGND
24
7
PHASE
10
9
42
8
VIN
VIN
VIN
NC
PGND
6
24
PGND
22
6
GH
5
41
CGND
GND
PGND
25
PGND
26
5
41
GH
2
CGND
GND
26
PGND
3
PGND
4
BOOT
27
PGND
3
VDRV
28
PGND
2
VCIN
PGND
25
1
VCIN
4
BOOT
PGND
27
VDRV
PGND
28
SMOD#
VSWH
VSWH
VSWH
43
29
30
1
SMOD#
VSWH
VSWH
VSWH
10
43
29
30
A
+
COUT14
330uF
2.5V
TECHNOLOGY
COUT12
330uF
2.5V
VOSB-
+
VOSB+
E27
VOSB-
GND
VOUTB
1.2V / 50A
VOSB+
COUT11
330uF
2.5V
J12
+
J11
E26
DATE:
N/A
SIZE
LTC3860EUH
E
DEMO CIRCUIT 1755A
Monday, January 16, 2012
IC NO.
SHEET 2
OF 3
2
REV.
1630 McCarthy Blvd.
Milpitas, CA 95035
Phone: (408)432-1900 www.linear.com
Fax: (408)434-0507
LTC Confidential-For Customer Use Only
COUT13
330uF
2.5V
R56
10
+
VOB+
R53
10
DUAL OUTPUT 4 -PHASE STEP-DOWN CONVERTER
TITLE: SCHEMATIC
COUT19
100uF
6.3V
1206
+
COUT17
100uF
6.3V
1206
COUT15
330uF
2.5V
COUT20
100uF
6.3V
1206
COUT16
330uF
2.5V
COUT18
100uF
6.3V
1206
E
1
2
3
4
DEMO MANUAL DC1755A
SCHEMATIC DIAGRAM
dc1755af
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.
1
2
3
4
COUT21
7343H
OPT
+
COUT22
7343H
OPT
E25
ON
OFF
JP3
3
2
1
R75
10k
1
+
COUT41
OPT
1206
VOA+
COUT24
7343H
OPT
R97
105K
R105
20K
0
1206
R90
C30
10pF
C25
1uF
5VBIAS
A
+
COUT42
OPT
1206
COUT25
7343H
OPT
1
+
COUT43
OPT
1206
COUT26
7343H
OPT
E23
E19
R80
OPT
1%
2010
COUT44
OPT
1206
COUT27
OPT
1206
ISTEPA-
4
3
2
1
VIN
SHDN
FB
BD
VIN
1uF
C28
C26
10uF
L5
9
GND
EXPOSED
PAD
GND
DA
BOOST
SW
U7
LT3502EDC
5
6
7
8
27uH
WURTH EL.7447789127
J7
B
C27
0.1uF
16V
COUT28
OPT
1206
LOAD STEP
10mV / Amp
ISTEPA+
Q2
SUD50N03-09P
OPT
BIA SUPPLY & UVLO CIRCUIT
R114
OPT
COUT23
7343H
OPT
+
R79
0.010
1%
2010
OPTIONAL COUT
E21
E17
INTERNAL BIAS
VIN
5V / 400mA
+
VOA+
GND
PULSE GEN A
Q1
SUD50N03-09P
2
3
5% DUTY CYLCE MAX.
2
3
COUT30
OPT
1206
C29
2.2uF
16V
VIN
E22
E18
COUT31
7343H
OPT
COUT32
7343H
OPT
COUT45
OPT
1206
VOB+
+
R76
10k
RUNA RUNB
R93
100
R106
10K
R100
127K
1%
3
2
1
COUT33
7343H
OPT
COUT46
OPT
1206
+
1
GND
4
R96
R95
R94
R92
OPT
OPT
OPT
OPT
COUT34
7343H
OPT
COUT47
OPT
1206
+
R81
0.010
1%
2010
1
C
UVLO THRESHOLD = 5.5V RISING
LT6703IDC-3
+INA
VS
OUT
U8
R108
OPT
D1
BAV170
SOT23
5VBIAS
UVLO CIRCUIT
R115
OPT
+
VOB+
GND
PULSE GEN B
Q4
SUD50N03-09P
5% DUTY CYLCE MAX.
D2
PMEG4005AEA
COUT29
OPT
1206
VOUTA
C
COUT48
OPT
1206
COUT35
7343H
OPT
THDN4
THDN3
THDN2
THDN1
+
R82
OPT
1%
2010
+
VOB+
CLKINA
SGND
SGND
SGND
RUNA
TRACK/SSA
COMPA
IAVGA
RIGHT
ANGLE
HEADER
COUT37
OPT
1206
E24
E20
J8
1
8
7
6
5
4
3
2
IAVGA
D
COUT40
OPT
1206
R85
OPT
PWMEN2
R77
OPT
PWMEN1
OPT
OPT
OPT
OPT
R86
OPT
R84
R83
PWMEN4
R74
R78
OPT
PWMEN3
R73
DISBL#2
DISBL#1
PWM ENABLE CIRCUIT FOR
NON-THREE STATE
COMPATIBLE DRMOS
E
R102 OPT
2010
2010
VOB+
R101 OPT
IAVGB
COMPA
OPT
R88
R103 OPT
D
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
AK
MIKE S.
SCALE = NONE
LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A
CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS;
HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO
PCB DES.
VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL
APP ENG.
APPLICATION. COMPONENT SUBSTITUTION AND PRINTED
CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT
PERFORMANCE OR RELIABILITY. CONTACT LINEAR
TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
VCCA
RUNB
FBA
MILL MAXX
803-43-008-20-001000
CLKOUTB
SGND
SGND
SGND
RUNB
TRACK/SSB
COMPB
IAVGB
1630 McCarthy Blvd.
Milpitas, CA 95035
Phone: (408)432-1900 www.linear.com
Fax: (408)434-0507
LTC Confidential-For Customer Use Only
CONNECT TO
PARALLEL
DC1755A
CLKOUTB
8
7
6
5
4
3
2
1
RIGHT
ANGLE
J10 SOCKET
DISBL#4
DISBL#3
DATE:
N/A
SIZE
LTC3860EUH
E
DEMO CIRCUIT 1755A
Monday, January 16, 2012
IC NO.
SHEET 3
OF 3
2
REV.
DUAL OUTPUT 4 -PHASE STEP-DOWN CONVERTER
TECHNOLOGY
R104 OPT
TITLE: SCHEMATIC
FBB
OPT
R91
RUNA
TRACK/SSA TRACK/SSB
APPROVALS
VCCB
COMPB
OPT
R89
OPTIONAL COMPONENTS FOR SINGLE OUTPUT
CONVERTER WITH 4,6 or 12 PHASES
COUT39
OPT
1206
VOA+
OPT
R87
COUT38
OPT
1206
ISTEPB-
ISTEPB+
VOUTB
CUSTOMER NOTICE
CONNECT TO
PARALLEL
DC1755A
CLKINA
MILL MAXX
802-40-008-20-001000
J9
COUT36
7343H
OPT
LOAD STEP
10mV / Amp
Q3
SUD50N03-09P
OPT
DYNAMIC LOAD CIRCUIT FOR VOUTB
2
VOA+
1
2
3
DYNAMIC LOAD CIRCUIT FOR VOUTA
B
3
2
3
A
1
2
3
4
DEMO MANUAL DC1755A
SCHEMATIC DIAGRAM
dc1755af
11
DEMO MANUAL DC1755A
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
dc1755af
12 Linear Technology Corporation
LT 0112 • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900
●
FAX: (408) 434-0507 ● www.linear.com
© LINEAR TECHNOLOGY CORPORATION 2012
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