1
dc1753bf
DEMO MANUAL DC1753B
Description
LTC3880EUJ
Dual Phase Step-Down
DC/DC Controller with
Digital Power Management
Demonstration circuit 1753B is a dual phase single-output,
synchronous buck converter featuring the LT C
®
3880EUJ,
a dual phase current mode controller with digital power
system management. There are two versions of the board
available:
n DC1753B-A: senses inductor current across a sense
resistor and has a default switching Freq of 350kHz.
n DC1753B-B: senses inductor current with the inductor
DCR and has a default switching Freq of 425kHz.
Either version can be populated with the LTC3880EUJ-1,
which allows the user to provide bias power to the IC from
an external power supply.
The output voltage of the board can be programmed from
0.5V to 3.3V, with output current up to 40A. The factory
default setting for the output is 1.8V.
The DC1753B powers up to default settings and pro-
duces power based on configuration resistors without the
need for any serial bus communication. This allows easy
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and
LTpowerPlay is a trademark of Linear Technology Corporation. All other trademarks are the
property of their respective owners.
performance summary
evaluation of the DC/DC converter aspects of the LTC3880.
To fully explore the extensive digital power management
features of the part, download the LTpowerPlay™ GUI
software onto your PC and use LT C ’s I2C/SMBus/PMBus
dongle DC1613A to connect to the board. LTpowerPlay
allows the user to reconfigure the part on-the-fly and store
the configuration in EEPROM, view telemetry of voltage,
current, temperature and fault status.
GUI DOWNLOAD
The software can be downloaded from:
http://www.linear.com/ltpowerplay
For more details and instructions of LTpowerPlay, please
refer to the LTpowerPlay for LTC3880 Quick Start Guide.
Design files for this circuit board are available at
http://www.linear.com/demo/DC1753B
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
VIN Input Supply Range 6.5 12 24 V
VOUT Output Voltage Range IOUT = 0A to 20A, VIN = 6.5V to 24V 0.5 1.8 3.3 V
VOUT_ACCURACY Output Voltage Accuracy IOUT = 0A to 20A, VIN = 6.5V to 24V
VOUT for 0.5V to 3.3V
±0.5 %
IOUT Output Current Range 0 40 A
fSW, A Factory Default Switching, Freq: A (RSENSE) 350 kHz
fSW, B Factory Default Switching, Freq: B (DCR) 425 kHz
EFFICIENCY Peak Efficiency VOUT = 1.8V, See Figures 6 and 7 91.8 %
Specifications are at TA = 25°C
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dc1753bf
DEMO MANUAL DC1753B
dc1753b F01
LTC3880
Demo Board
DC1753B
USB to
I2C/PMBus Dongle
DC1613A
+12V
Power Supply
LOAD
USB CABLE
12-PIN J10
CONNECTOR
VOUT
VIN
Quick start proceDure
Figure 1. Demo Setup with PC
Demonstration circuit 1753B makes it easy to evaluate
the performance of the LTC3880. Refer to Figure 3 for
proper measurement equipment setup and follow the
procedure below.
NOTE: When measuring the input or output voltage ripple,
care must be taken to avoid a long ground lead on the
oscilloscope probe. Measure the output voltage ripple by
touching the probe tip directly across the C20 or C23. See
Figure 5 for the proper scope probe technique.
1. Make sure jumpers are in the following positions:
JUMPER POSITION FUNCTION
JP1 OFF Write Protection of LTC3880
JP3 ON LED Indicator
JP4 OFF EXTVCC_DRV: External VCC for the LTC3880-1
JP5 C GPIO0B to GPIO1B: Tie GPIOs Together
2. With power off, connect the input power supply to
VIN and GND. Connect active load to outputs.
3. Make sure RUN switch is OFF.
4. Turn on the power at the input. .
NOTE: Make sure that the input voltage does not ex-
ceed 24V.
5. Turn on the RUN switch as desired.
6. Check for the correct output voltages. VOUT = 1.8V
± 0.5%.
NOTE: If there is no output, temporarily disconnect
the load to make sure that the load is not set too high.
7. Once the proper output voltages are established, adjust
the loads within the operating range and observe the
output voltage regulation, ripple voltage, efficiency
and other parameters.
8. Connect the dongle and control the output voltages
from the GUI. See next section for details.
CONNECTING A PC TO DC1753B
You can use a PC to reconfigure the power management
features of the LTC3880, such as: nominal VOUT, margin
set points, OV/UV limits, temperature fault limits, sequenc-
ing parameters, the fault log, fault responses, GPIOs and
other functionality. The DC1613A dongle may be plugged
in regardless of whether or not VIN is present.
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dc1753bf
DEMO MANUAL DC1753B
Quick start proceDure
Plug the dongle into the correct connector. The dongle
can be hot plugged.
Figure 2. Dongle Connector Locations
Figure 3. Dual Phase Single-Output Test Setup
dc1753b F02
DC1613A
CONNECTOR
dc1753b F03
+
–
SHUNT
VOUT
LOAD
RUN
SWITCH1
POWER
SUPPLY
–
+
+
–
+
–
+–
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dc1753bf
DEMO MANUAL DC1753B
Combining DC1753B with Other Digital Power Demo
Boards
The DC1753B may be plugged together in a multiboard
array with other digital power boards using J7 and J8.
Measuring Efficiency
To accurately measure efficiency of any configuration, do
the following:
n Remove R65 (bleeder resistor on bottom side of board).
n Set JP3 to OFF to disable the regulator that provides
power to LEDs.
n Measure VIN across the input ceramic capacitor (C18,
C19). Measure VOUT across the output ceramic capaci-
tor (C24, C25).
Evaluating the LTC3880-1
For applications that require the highest possible ef-
ficiency, the LTC3880-1 allows the user to supply the
bias current and gate driver current from an external
power supply. Connect the power supply, 4.8V to 5.2V,
to the INTVCC/EXTVCC pin. Obtain a DC1753B with an
LTC3880-1 installed from your Linear Technology Field
Applications Engineer.
To use the on-board LDO to drive INTVCC, make the
following modifications to the demo board:
n Set JP4 to ON so that U7 provides the drive to
INTVCC. U7 takes the place of the external power supply.
n Install R60.
To accurately measure efficiency of a demo board contain-
ing an LTC3880-1:
n Drive INTVCC from an external source through the
pin named: INTVCC/EXTVCC. Install R60, R65 if
installed
n Set JP4 to OFF to disable U7.
n Set JP3 to OFF to disable the regulator that provides
power to LEDs.
n Measure VIN across the input ceramic capacitor (C18,
C19). Measure VOUT across the output ceramic capaci-
tor (C24, C25).
Measuring Output Ripple Voltage
An accurate ripple measurement may be performed by
using the configuration in Figure 5 across C20 or C23.
Quick start proceDure
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DEMO MANUAL DC1753B
Figure 5. Measuring Output Voltage Ripple
Quick start proceDure
+ –
VOUT GND
COUT
dc1753b F05
Figure 4. Jumper Locations: JP3, JP4, R60, INTVCC/EXTVCC Turret
JP3
JP4
INTVCC
EXTVCC
R60
dc1753b F04
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DEMO MANUAL DC1753B
Figure 7. Typical Efficiency Curves, DCR Current Sensing, 12VIN, fSW = 425kHz
Figure 6. Typical Efficiency Curves, Sense Resistor Current Sensing, 12VIN, fSW = 350kHz
Quick start proceDure
OUTPUT CURRENT (A)
0
80
EFFICIENCY (%)
82
84
88
105 15 4030 352520
86
90
92
81
83
85
89
87
91
dc1753b F06
12VIN, 1.8VOUT, 350kHz, RSENSE
12VIN, 1.5VOUT, 350kHz, RSENSE
12VIN, 1.2VOUT, 350kHz, RSENSE
12VIN, 1.0VOUT, 350kHz, RSENSE
OUTPUT CURRENT (A)
0
80
EFFICIENCY (%)
82
84
88
105 15 4030 352520
86
90
92
81
83
85
89
87
91
dc1753b F07
12VIN, 1.8VOUT, 425kHz, DCR SENSE
12VIN, 1.5VOUT, 425kHz, DCR SENSE
12VIN, 1.2VOUT, 425kHz, DCR SENSE
12VIN, 1.0VOUT, 425kHz, DCR SENSE
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dc1753bf
DEMO MANUAL DC1753B
Figure 8. LTpowerPlay Software GUI
LTpowerPlay Software GUI
LTpowerPlay is a powerful Windows based development
environment that supports Linear Technology digital power
ICs with EEPROM, including the LTC3880, LTC2974 and
LTC2978, the quad and octal PMBus power supply man-
agers. The software supports a variety of different tasks.
You can use LTpowerPlay to evaluate Linear Technology
ICs by connecting to a demo board system. LTpowerPlay
can also be used in an offline mode (with no hardware
present) in order to build a multichip configuration file that
can be saved and reloaded at a later time. LTpowerPlay
provides unprecedented diagnostic and debug features. It
becomes a valuable diagnostic tool during board bring-up
to program or tweak the power management scheme in
a system, or to diagnose power issues when bringing up
rails. LTpowerPlay utilizes the DC1613A USB-to-SMBus
controller to communicate with one of many potential
targets, including the LTC2974’s DC1978A demo system,
or a customer board. The software also provides an au-
tomatic update feature to keep the software current with
the latest set of device drivers and documentation. The
LTpowerPlay software can be downloaded from:
http://linear.com/ltpowerplay
To access technical support documents for LT C Digital
Power Products visit Help. View online help on the
LTpowerPlay menu.
Quick start proceDure
8
dc1753bf
DEMO MANUAL DC1753B
Gui Quick start proceDure
LTpowerPlay Software GUI
The following procedure describes how to use LTpowerPlay
to monitor and change the settings of LTC3880.
1. Download and install the LTPowerPlay GUI:
http://linear.com/ltpowerplay
2. Launch the LTpowerPlay GUI.
a. The GUI should automatically identify the LTC3880. The
system tree on the left hand side should look like this:
b. A green message box shows for a few seconds in the
lower left hand corner, confirming that the LTC3880 is
communicating:
c. In the tool bar, click the “R” (RAM to PC) icon to read
the RAM from the LTC3880. This reads the configuration
from the RAM of LTC3880 and loads it into the GUI.
d. To change the output voltage to a different value, like
1.5V: In the Config tab, type 1.5 in the VOUT_COMMAND
box, like this:
Then, click the “W” (PC to RAM) icon to write these register
values to the LTC3880. After finishing this step, you will
see the output voltage will change to 1.5V.
If the write is successful, this message appears:
e. To save the changes into the NVM: In the tool bar, click
the “RAM to NVM” button:
f. Save the demo board configuration to a (*.proj) file by
clicking the Save icon and save the file with a new file
name.
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DEMO MANUAL DC1753B
parts List
ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER
Required Circuit Components
1 3 C1, C2, C6 CAP., X7R, 0.1µF, 50V, 10%, 0603 AVX, 06035C104KAT2A
2 1 C17 CAP., X7R, 0.22µF, 25V, 10%, 0603 TDK, C1608X7R1E224K
3 2 C3, C9 CAP., X7R, 1µF, 16V, 10%, 0603 AVX, 0603YC105KAT2A
4 1 C5 CAP., X5R, 4.7µF, 25V, 0805 TAIYO YUDEN, TMK212BJ475KG-T
5 1 C8 CAP., X7R, 4700PF, 10%, 50V, 0603 AVX, 06035C472KAT2A
6 4 C10, C29, C11, C30 CAP, POSCAP, 330µF, 6.3V, D3L SANYO, 6TPF330M9L
7 1 C13 CAP, OS-CON 150µF, 35V SUNCON, 35HVP150M
8 4 C20, C23-25 CAP., X5R, 100µF, 6.3V, 1210 AVX, 12106D107MAT2A
9 2 C12, C14 CAP., X7R, 0.01µF, 10%, 50V, 0603 AVX, 06035C103KAT2A
10 2 C21, C22 CAP., X5R, 1000pF, 25, 10%, 0603 AVX, 06035C102JAT2A
11 2 C15, C16 CAP., X7R, 100pF, 5%, 50V, 0603 AVX, 06035C101KAT2A
12 4 C18, C19, C27, C28 CAP., X5R, 10µF, 35V, 1210 TAIYO YUDEN, GMK325BJ106KN
13 1 C48 CAP., X5R, 10µF, 6.3V 0603 TDK, C1608X5R0J106M
14 2 D1, D2 DIODE, SCHOTTKY, SOD-323 CENTRAL CMDSH-3TR
15 2 Q1, Q3 OPTIMOS3 POWER-TRANSISTOR, PG-TDSON-8 INFINEON, BSC050N03LS
16 2 Q2, Q4 OPTIMOS3 POWER-TRANSISTOR, PG-TDSON-8 INFINEON., BSC011N03LSI
17 2 Q5, Q6 TRANS, GP, SS, PNP, 40V, SOT-23 ON SEMI MMBT3906LT1G
18 1 Q11 MOSFET P-CH, 20V, 0.58A, SOT-23 VISHAY TP0101K-T1-E3
19 9 R5, R17, R39, R40-R42, R44, R45, R57 RES., CHIP, 10k, 5%, 0603 VISHAY, CRCW060310K0JNEA
20 1 R66 RES., CHIP, 24.3k, 1%, 0603 VISHAY, CRCW060324K3FKEA
21 10 R8, R25, R56, R59, R6, R29, R30, R34,
R67, R63
RES., CHIP, 0 0603 YAGEO, RC0603FR-070RL
22 1 R3 RES., CHIP, 4.87k, 1%, 0603 AAC, CR16-4871FM
23 1 R24 RES., CHIP, 15.8k, 1%, 0603 VISHAY, CRCW060315K8FKEA
24 1 R52 RES., CHIP, 2, 1%, 0603 YAGEO, RC0603FR-072RL
25 2 R10, R16 RES., 0.002, 2512, 1% PANASONIC, ERJ-M1WTF2M0U
26 4 R11, R12, R13, R14 RES., CHIP, 100, 1%, 0603 VISHAY, CRCW0603100RFKEA
27 2 L1, L2 INDUCTOR, 0.4µH VITEC., 59PR9875
28 1 U4 IC, LTC3880EUJ, QFN 6mm × 6mm LINEAR TECH., LTC3880EUJ#010J-1PBF
Gui Quick start proceDure
Loading a LTC3880 Configuration (*.proj) File with the GUI
n In the upper left hand corner of the GUI: File > Open > browse
to your *.proj file. This will load the file into the GUI.
n Click the “Go On Line” button to link the GUI to the
existing LTC3880, as this:
n Click on the “W” (PC to RAM) button. This loads the
configuration into LTC3880 RAM.
n Then, you can save the configuration to the EEPROM.
Please see previous step f for details.
DC1753B-A
10
dc1753bf
DEMO MANUAL DC1753B
parts List
ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER
Additional Circuit Components
1 1 C50 CAP., X7R, 0.1µF, 50V, 10%, 0603 AVX, 06035C104KAT2A
2 1 C49 CAP., X5R, 4.7µF, 10V, 0603 AVX, 0603ZD475KAT2A
3 0 C42-C45 CAP, POSCAP, 330µF, 6.3V, D3L
4 0 C4, C38 CAP., 0603
5 0 C32, C34 CAP., 1210
6 1 C46 CAP., X7R, 0.01µF, 10%, 50V, 0603 AVX, 06035C103KAT2A
7 1 C35 CAP., X5R, 10µF, 35V, 1206 TAIYO YUDEN, GMK316BJ106ML
8 1 C36 CAP., TANT LOW ESR, 3.3µF, 25V, 10% AVX, TPSB335K025R2000
9 2 C37, C40 CAP., X7R, 1µF, 50V, 1206 AVX, 12065C105KAT2A
10 1 C41 CAP., X7R, 2.2µF, 16V, 0805 AVX, 0805YC223KAT2A
11 1 D3 LED GREEN S-GW TYPE SMD PANASONIC LN1371SGTRP
12 1 D5 LED RED S-TYPE GULL WING SMD PANASONIC LN1271RTR
13 0 D6, D9 DIODE, SCHOTTKY, SOD-323 CENTRAL CMDSH-3TR
14 1 Q15 MOSFET SPEED SRS 30V, 30A, LFPAK RENESAS RJK0305DPB-00#J0
15 0 Q7, Q8, Q9, Q10 OPTIMOS3 POWER-TRANSISTOR, PG-TDSON-8
16 1 Q14 MOSFET P-CH, 20V, 0.58A, SOT-23 VISHAY TP0101K-T1-E3
17 1 Q12 MOSFET N-CH, 60V, 115MA, SOT-23 FAIRCHILD 2N7002A
18 4 R49, R62, R64, R66 RES CHIP, 10k, 5%, 0603 VISHAY, CRCW060310K0JNEA
19 4 R48, R90, R83, R77 RES CHIP, 0, 0603 YAGEO, RC0603FR-070RL
20 0 R18, R20, R22, R23, R32, R73, R70, R1,
R2, R7, R15, R94, R95, R81, R82, R96,
R79, R80
RES., CHIP, 0603
21 2 R84, R85 RES., CHIP, 4.99k, 1%, 0603 YEGEO, RC0603FR-074K99L
22 2 R50, R61 RES., CHIP, 1.5k, 1%, 0603 VISAY, CRCW06031K50FKEA
23 1 R53 RES., CHIP, 200, 1%, 0603 YAGEO, RC0603FR-07200RL
24 1 R55 RES., CHIP, 127, 1%, 0603 VISHAY, CRCW0603127RFKEA
25 0 R65 RES., CHIP, 30, 1%, 1W 2512
26 1 R68 RES., CHIP, 0.01, 1%, 2010 VISHAY, WSL2010R0100FEA
27 0 R60 RES., 0805
28 1 R38 RES., CHIP, 49.9, 1%, 0603
29 1 U5 IC, 24LC025-I/ST, SOIC MICROCHIP, 24LC025-I/ST
30 1 U6 IC, LT1129CS8-3.3 S8 PACKAGE LINEAR TECH. LT1129CS8-3.3
31 1 U7 IC, LT1129CS8-5, S8 PACKAGE LINEAR TECH, LT1129CS8-5
Hardware
1 4 JP1, JP3-JP5 0.100" SINGLE ROW HEADER, 3 PIN SAMTEC, TSW-103-07-L-S
2 4 JP1, JP3-JP5 SHUNT .100" BLK SAMTEC, SNT-100-B-G
3 1 SW1 CONNECTOR, SUB MINIATURE SLIDE SWITCHES C&K.,JS202011CQN
4 2 J1, J2 JACK, BANANA KEYSTONE 575-4
5 4 J3, J4(×2) STUD, TESTPIN PEM KFH-032-10
6 4 J3, J4(×2) NUT, BRASS 10-32 ANY #10-32
7 1 J14 CONN., HEADER, 2 × 7, 2mm, R/A (F) SULLINS, NPPN072FJFN-RC
8 1 J15 CONN., HEADER, 2 × 7, 2mm, R/A (M) MOLEX, 87760-1416
9 0 J9 (OPT) HEADER 14POS 2mm VERT GOLD MOLEX 87831-1420
10 1 J10 CONN HEADER 12POS 2mm, STR DL PCB FCI 98414-G06-12ULF
11 1 J11 CONN, BNC, 5 PINS CONNEX, 112404
12 28 E1-E21, E23, E24, E25, E27, E31, E33 TESTPOINT, TURRET, .062" MILL-MAX, 2308-2-00-80-00-00-07-0
DC1753B-A
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dc1753bf
DEMO MANUAL DC1753B
Figure 9. Demo Circuit 1753B Dual-Phase, Single-Output, Step-Down DC/DC Converter with Digital Power Management
5
5
4
4
3
3
2
2
1
1
D D
CC
BB
A A
R1,R2
ASSY
Hu4.00OPT 100 1nF
-A VERSION R SENSE
1.4K
C21,C22
00.56uH
L1,L2
0.22uF
R6,R29
CURRENT SENSE CONNECTIONS
SGND AND PGND CONNECTED AT
A SINGLE NODE NEAR U1
ON
OFF
WP
OPEN
C4,C38
1.0 uF
R12,R14
100
1.4K
R11,R13R10,R16
R30,R34
0
0
R7,R15
0 0.002
6.5V - 24V
-B VERSION DCR SENSE
*
35V
OPT
OPT
ADJ., MAX 40A
*
*
*
*
*
*
*
*
*
*
*
*
*
***
*
*
*
2. INSTALL SHUNTS AS SHOWN.
1. ALL RESISTORS ARE IN OHMS, 0603.
ALL CAPACITORS ARE IN MICROFARADS, 0603.
NOTE: UNLESS OTHERWISE SPECIFIED
D3L D3L D3L D3L
D3L D3L D3L D3L
2512
2512
OPT OPT
OPT OPT
PLACE Q5,Q6 NEAR L1,L2. RESPECTIVELY
OPT
OPT OPT
CONVERTER WITH DIGITAL POWER MANAGEMENT
MMBT3906LT
MMBT3906LT
0805 CMDSH-3TR CMDSH-3TR
1210 1210 1210
1210 1210
FSW
350KHz
425KHz
FREQ_CFG
ASEL
TSNS0
ITH
SW1
BOOST0
ITH_TP
TSNS1
ISNS0-
ISNS0+
BG0
SW0
TG0
ISNS1+
ISNS1-
VOUT_CFG
VDD25
WP
INTVCC
VTRIM_CFG
BG1
BOOST1
VIN
VDD33
VDD33
VDD33
VDD33
VOUT
VIN
VDD25
VIN
SCL
SDA
SYNC
ALERTB
GPIO0B
VSENSE0+
VSENSE0-
SHARE_CLK
RUN
EXTVCC_DRV
GPIO1B
VIN
REVISION HISTORY
DESCRIPTION DATEAPPROVEDECO REV
YI S.
PRODUCTION 41-6-61
__
REVISION HISTORY
DESCRIPTION DATEAPPROVEDECO REV
YI S.
PRODUCTION 41-6-61
__
REVISION HISTORY
DESCRIPTION DATEAPPROVEDECO REV
YI S.
PRODUCTION 41-6-61
__
SIZE
DATE:
.VER.ON CI
SHEET OF
TITLE:
APPROVALS
PCB DES.
APP ENG.
TECHNOLOGY Fax: (408)434-0507
Milpitas, CA 95035
Phone: (408)432-1900
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, July 21, 2014
1 3
DUAL-PHASE SINGLE OUTPUT STEP-DOWN DC/DC
HZ
YI S.
N/A
LTC3880EUJ
DEMO CIRCUIT 1753B-A/B
SIZE
DATE:
.VER.ON CI
SHEET OF
TITLE:
APPROVALS
PCB DES.
APP ENG.
TECHNOLOGY Fax: (408)434-0507
Milpitas, CA 95035
Phone: (408)432-1900
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, July 21, 2014
1 3
DUAL-PHASE SINGLE OUTPUT STEP-DOWN DC/DC
HZ
YI S.
N/A
LTC3880EUJ
DEMO CIRCUIT 1753B-A/B
SIZE
DATE:
.VER.ON CI
SHEET OF
TITLE:
APPROVALS
PCB DES.
APP ENG.
TECHNOLOGY Fax: (408)434-0507
Milpitas, CA 95035
Phone: (408)432-1900
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, July 21, 2014
1 3
DUAL-PHASE SINGLE OUTPUT STEP-DOWN DC/DC
HZ
YI S.
N/A
LTC3880EUJ
DEMO CIRCUIT 1753B-A/B
C12
10nF
C12
10nF
R14R14
C28 10uFC28 10uF
E2
VIN
E2
VIN
D2D2
21
R22
OPT
R22
OPT
E8
GND_SNS
E8
GND_SNS
R32
OPT
R32
OPT
L2L2
E4
VDD33
E4
VDD33
R40
10K
R40
10K
R7R7
C3
1uF
C3
1uF
J4
GND
J4
GND
R57
10K
R57
10K
R18
OPT
R18
OPT
R1R1
E11
SGND E11
SGND
C25
100uF
C25
100uF
C27 10uFC27 10uF
C32C32
L1L1
R44 10KR44 10K
Q6Q6
Q9
OPT
Q9
OPT
1
25
3
4
C24
100uF
C24
100uF
C23
100uF
C23
100uF
R42
10K
R42
10K
R34R34
R11R11
E10
INTVCC/EXTVCC
E10
INTVCC/EXTVCC
R41
10K
R41
10K
J1
VIN
J1
VIN
R29R29
C16
100pF
C16
100pF C22
*
C22
*
R23
OPT
R23
OPT
C2 100nFC2 100nFR59 0R59 0
R25
0
R25
0
Q8
OPT
Q8
OPT
1
25
3
4
+
C13
150uF
+
C13
150uF
+
C44
+
C44
C34C34
+
C42
+
C42
R45 10KR45 10K
R8
0
R8
0
E9
ITH
E9
ITH
R10R10
J2
GND
J2
GND
C4C4
C48
10uF
C48
10uF
R67 0R67 0
C15
100pF
C15
100pF R3
4.87K
R3
4.87K
C8
4.7nF
C8
4.7nF
E5
VDD25
E5
VDD25
R12R12
C9
1uF
C9
1uF
+
C43
+
C43
C18 10uFC18 10uF
Q5Q5
C21C21
E1
GND
E1
GND
C1 100nFC1 100nF
+
C30
330uF
+
C30
330uF
R60 OPTR60 OPT
Q3
BSC050N03LS
Q3
BSC050N03LS
1
25
3
4
U4
LTC3880EUJ
U4
LTC3880EUJ
VSENSE0+ 1
VSENSE0- 2
ISNS1+ 3
ISNS1- 4
ITH0
5
ISNS0+ 6
ISNS0- 7
SYNC
8
SCL
9
SDA
10
ALERT
11
GPIO0 12
GPIO1 13
RUN0
14
RUN1
15
ASEL
16
FREQ_CFG
17
VOUT0_CFG
18
VOUT1_CFG
19
VTRIM0_CFG
20
VTRIM1_CFG
21
VDD25 22
WP
23
SC
24
VDD33 25
ITH1
26
VSENSE1 27
TSNS1
28
SW1 29
TG1 30
BOOST1 31
BG1 32
INTVCC 33
PGND
34
VIN 35
BG0 36
BOOST0 37
TG0 38
SW0 39
TSNS0
40
GND
41
C38C38
Q10
OPT
Q10
OPT
1
25
3
4
R17
10K
R17
10K
R13R13
R20
OPT
R20
OPT
R63 0R63 0
Q1
BSC050N03LS
Q1
BSC050N03LS
1
25
3
4
R15R15
+
C29
330uF
+
C29
330uF
+
C45
+
C45
E6
GND
E6
GND
E7
VOUT_SNS
E7
VOUT_SNS
+
C11
330uF
+
C11
330uF
R2R2
R52 2R52 2
C14
10nF
C14
10nF
C19 10uFC19 10uF
R73
OPT
R73
OPT
R48 0R48 0
R16R16
D1D1
21
R39
10K
R39
10K
R56 0R56 0
E3
GND
E3
GND
JP1JP1
1
2
3
Q4
BSC011N03LSI
Q4
BSC011N03LSI
1
25
3
4
J3
VOUT
J3
VOUT
R30R30
R24
15.8K
R24
15.8K
C6
100nF
C6
100nF
Q2
BSC011N03LSI
Q2
BSC011N03LSI
1
25
3
4
Q7
OPT
Q7
OPT
1
25
3
4
R6R6
+
C10
330uF
+
C10
330uF
C20
100uF
C20
100uF
C17
0.22uF
C17
0.22uF
C5
4.7uF
C5
4.7uF
R5
10K
R5
10K
schematic DiaGram
12
dc1753bf
DEMO MANUAL DC1753B
Figure 10. Demo Circuit 1753B Dual-Phase, Single-Output, Step-Down DC/DC Converter with Digital Power Management
5
5
4
4
3
3
2
2
1
1
DD
C C
BB
A A
CONVERTER WITH DIGITAL POWER MANAGEMENT
CNC
GPIO0-GPIO1
TO DC1613A
ALL PARTS ON THIS PAGE ARE FOR DEMO BOARD ONLY, NOT NEEDED IN CUSTOMER DESIGN
ON
OFF
RUN
1206
AUXVCC
EEWP
EESDA
EESCL
VDD33
3V3
VIN
3V3
VIN
ALERTB SDA SCL
RUN
RUN1
GPIO1B
GPIO0B
SYNC
SHARE_CLK
SIZE
DATE:
.VER.ON CI
SHEET OF
TITLE:
APPROVALS
PCB DES.
APP ENG.
TECHNOLOGY Fax: (408)434-0507
Milpitas, CA 95035
Phone: (408)432-1900
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, July 21, 2014
2 3
DUAL-PHASE SINGLE OUTPUT STEP-DOWN DC/DC
HZ
YI S.
N/A
LTC3880EUJ
DEMO CIRCUIT 1753B-A/B
SIZE
DATE:
.VER.ON CI
SHEET OF
TITLE:
APPROVALS
PCB DES.
APP ENG.
TECHNOLOGY Fax: (408)434-0507
Milpitas, CA 95035
Phone: (408)432-1900
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, July 21, 2014
2 3
DUAL-PHASE SINGLE OUTPUT STEP-DOWN DC/DC
HZ
YI S.
N/A
LTC3880EUJ
DEMO CIRCUIT 1753B-A/B
SIZE
DATE:
.VER.ON CI
SHEET OF
TITLE:
APPROVALS
PCB DES.
APP ENG.
TECHNOLOGY Fax: (408)434-0507
Milpitas, CA 95035
Phone: (408)432-1900
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, July 21, 2014
2 3
DUAL-PHASE SINGLE OUTPUT STEP-DOWN DC/DC
HZ
YI S.
N/A
LTC3880EUJ
DEMO CIRCUIT 1753B-A/B
R82 OPTR82 OPT
R49
10.0K
R49
10.0K
C46
10nF
C46
10nF
E17
SYNC
E17
SYNC
E21
GND
E21
GND
R77
10
R77
10
R83
0
R83
0
J15 DEMO HEADER (M)J15 DEMO HEADER (M)
FAULTB 1
CTRL 2
ALERTB 3
SDA 4
SHARE_CLK 5
SCL 6
RESETB 7
AUXP 8
UNUSED 9
UNUSED 10
GND 11
GND 12
12V 13
12V 14
R94
OPT
R94
OPT
E13
ALERTB
E13
ALERTB
R84
4.99K
R84
4.99K
E20
RUN
E20
RUN
D9
OPT
D9
OPT
SW1SW1
1
2
34
5
6
E15
SCL
E15
SCL
U5
24LC025-I/ST
U5
24LC025-I/ST
A0
1
A1
2
A2
3
VSS
4SDA 5
SCL 6
WP 7
VCC 8
R95
OPT
R95
OPT
E16
SHARE_CLK
E16
SHARE_CLK
E33
RUN1
E33
RUN1
E19
GPIO0B
E19
GPIO0B
R85
4.99K
R85
4.99K
E14
SDA
E14
SDA
JP5JP5
1
2
3
R79
0
R79
0
C50
100nF
C50
100nF
D6
OPT
D6
OPT
R90
0
R90
0
R81 OPTR81 OPT
E31
SGND
E31
SGND
R86
OPT
R86
OPT
E25
GPIO1B
E25
GPIO1B
R80
OPT
R80
OPT
R87
OPT
R87
OPT
J10J10
AUXP 1
SDA 2
GND 3
SCL 4
LGKPWR 5
ALERTB 6
GPIO_1 7
OUTEN_0 8
OUTEN_1 9
GND 10
AUXSCL 11
AUXSDA 12
J14 DEMO HEADER (F)J14 DEMO HEADER (F)
FAULTB
1
CTRL
2
ALERTB
3
SDA
4
SHARE_CLK
5
SCL
6
RESETB
7
AUXP
8
UNUSED
9
UNUSED
10
GND
11
GND
12
12V
13
12V
14
R96
OPT
R96
OPT
R70
OPT
R70
OPT
schematic DiaGram
13
dc1753bf
DEMO MANUAL DC1753B
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.
Figure 11. Demo Circuit 1753B Dual-Phase, Single-Output, Step-Down DC/DC Converter with Digital Power Management
5
5
4
4
3
3
2
2
1
1
DD
C C
BB
A A
LED
ON
OFF
GPIO0B
ALERTB
ALL PARTS ON THIS PAGE ARE FOR DEMO ONLY, NOT NEEDED IN CUSTOMER DESIGN
EXTVCC_DRV
ON
OFF
DYNAMIC LOAD CIRCUIT
DO NOT EXCEED 5% DUTY CYCLE!
NOTE:
PULSE OUT
10mV / AMP
VOUT
IOUT
TST 2512
OPT
0805
3528 1206 1206
1206
CONVERTER WITH DIGITAL POWER MANAGEMENT
+3.3V
VIN
+3.3V
+3.3V
VOUT
VIN
VOUT
3V3 VDD33
VIN
EXTVCC_DRV
GPIO0B
ALERTB
VIN
SIZE
DATE:
.VER.ON CI
SHEET OF
TITLE:
APPROVALS
PCB DES.
APP ENG.
TECHNOLOGY Fax: (408)434-0507
Milpitas, CA 95035
Phone: (408)432-1900
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
Friday, August 29, 2014
3 3
DUAL-PHASE SINGLE OUTPUT STEP-DOWN DC/DC
HZ
YI S.
N/A
LTC3880EUJ
DEMO CIRCUIT 1753B-A/B
SIZE
DATE:
.VER.ON CI
SHEET OF
TITLE:
APPROVALS
PCB DES.
APP ENG.
TECHNOLOGY Fax: (408)434-0507
Milpitas, CA 95035
Phone: (408)432-1900
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
Friday, August 29, 2014
3 3
DUAL-PHASE SINGLE OUTPUT STEP-DOWN DC/DC
HZ
YI S.
N/A
LTC3880EUJ
DEMO CIRCUIT 1753B-A/B
SIZE
DATE:
.VER.ON CI
SHEET OF
TITLE:
APPROVALS
PCB DES.
APP ENG.
TECHNOLOGY Fax: (408)434-0507
Milpitas, CA 95035
Phone: (408)432-1900
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
Friday, August 29, 2014
3 3
DUAL-PHASE SINGLE OUTPUT STEP-DOWN DC/DC
HZ
YI S.
N/A
LTC3880EUJ
DEMO CIRCUIT 1753B-A/B
D3
GREEN
D3
GREEN
12
R65
30
1W
R65
30
1W
U7
LT1129CS8-5
U7
LT1129CS8-5
OUTPUT 1
SENSE/ADJ 2
GND 3
NC 4
SHDN
5
GND
6
GND
7
VIN
8
R53
200
R53
200
C35
10uF
C35
10uF
C49
4.7uF
C49
4.7uF
R38 49.9R38 49.9 J11J11
1
2
3
4
5
U6
LT1129CS8-3.3
U6
LT1129CS8-3.3
OUTPUT 1
SENSE/ADJ 2
GND 3
NC 4
SHDN
5
GND
6
GND
7
VIN
8
Q14
TP0101K
Q14
TP0101K
23
1
R64
10K
R64
10K
R68
0.01
R68
0.01
C40
1uF
C40
1uF
JP3JP3
1
2
3
R66 10KR66 10K
R61
1.5K
R61
1.5K
D5
RED
D5
RED
12
+
C36
3.3uF
+
C36
3.3uF
E27E27
Q11
TP0101K
Q11
TP0101K
2
3
1
R62
10K
R62
10K
C37
1uF
C37
1uF
E23
PULSE IN
E23
PULSE IN
R50
1.5K
R50
1.5K
C41
0.22uF
C41
0.22uF
R55
127
R55
127
E24
GND
E24
GND
Q12
2N7002A
Q12
2N7002A
2 3
1
Q15
RJK0305DPB
Q15
RJK0305DPB
1
25
3
4
JP4JP4
1
2
3
schematic DiaGram
14
dc1753bf
DEMO MANUAL DC1753B
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com
LINEAR TECHNOLOGY CORPORATION 2015
LT 0715 • PRINTED IN USA
DEMONSTRATION BOARD IMPORTANT NOTICE
Linear Technology Corporation (LT C ) 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 LT C 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 LT C 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. LT C assumes no liability for applications assistance,
customer product design, software performance, or infringement of patents or any other intellectual property rights of any kind.
LT C 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 LT C applica-
tion engineer.
Mailing Address:
Linear Technology
1630 McCarthy Blvd.
Milpitas, CA 95035
Copyright © 2004, Linear Technology Corporation
