Analog Devices Linear DC2331A-A Quick setup guide

1
DEMO MANUAL
DC2331A-A/DC2331A-B
Rev. 0
DESCRIPTION
LT8550
4-Phase DC/DC Expander with Internal
Gate Drivers for Buck Converters
Demonstration circuit 2331A-A/2331A-B is a 4-phase
DC/DC expander with internal gate drivers for buck con-
verters that features the LT
®
8550. The demonstration cir-
cuit expands (increases) the number of power sections
for a LT3763 60V step-down controller to provide higher
output power. The increased number of power sections
allowed by the LT8550 results in more available output
power without a corresponding increase in the difficulty
of the design or a sacrifice of LT3763 features. The demo
board uses the multi-chip (master-slave) feature of the
LT8550 so the total number of power sections can be
increased in four power section increments:
• DC2331A-A has one power section for the LT3763 pri-
mary controller and an additional four power sections
for its LT8550 which is configured as a master
• DC2331A-B does not have a primary controller, and
its LT8550 is configured as a slave with four power
sections
The DC2331A-A and DC2331A-B use the same PCB and
the PCB is an example of how ground plane layers should
be configured and traces routed for reliable performance.
The input voltage range of DC2331A-A/DC2331A-B is from
14V to 56V and the output is 12V. The maximum output
current is 14A per power section, so the maximum output
current of DC2331A-A is 70A and each slave DC2331A-B
adds an additional 56A of output current capability. The
switching frequency is 250kHz and at 24V input to 12V
OUT
at full load, the efficiency of DC2331A-A is 97.5%.
The DC2331A-A/DC2331A-B is designed so it is easy to
add power sections and increase output power. The mas-
ter and slave assemblies are programmed using jumpers
and adjustment of regulation loop compensation is usu-
ally not necessary as power sections are added. The con-
trol signal interface between master and slave assemblies
is a common ribbon cable. The power cabling between
master and slave assemblies is similarly simple. All registered trademarks and trademarks are the property of their respective owners.
The DC2331A-A/DC2331A-B’s jumpers program the
phase relationship between the power sections and turn
phase shedding on and off. Jumper JP5 programs the
LT8550 SYNC pin for master or slave operation and allows
DC2331A-A to be synchronized to an external clock. The
VCC and RSYNC JP5 settings—and the DC2331A assem-
blies in general—are forward compatible with the next
generation of phase expander ICs.
A ribbon cable provided with DC2331A-B interfaces the
control logic between a master DC2331A-A and a sin-
gle or multiple slave DC2331A-B(s). Each DC2331A-A/
DC2331A-B has two identical ribbon cable headers, so
daisy-chain ribbon cables are not required, even for sys-
tems with multiple slave assemblies. The DC2331A-A/
DC2331A-B uses high current #10 bolt-on terminals for
the input supply and load connections;and a sufficient
quantity of #10 ring lugs is provided to parallel master and
slaves with minimal DC offset voltage between assem-
blies. VIN–, VIN+, VO–and VO+terminals allow convenient
monitoring of input and output voltages while minimizing
the measured I •R PCB voltage drops caused by high
currents.
The DC2331A-A/DC2331A-B has terminals for SHDN
and SYNC inputs to the LT8550. There are also terminals
that make it easy to monitor the control logic between
master and slave DC2331s. Removal of jumper resis-
tors can cleanly separate the electrical interface between
the LT3763 primary controller and the remainder of
DC2331A-A, making it possible to connect an alternate
primary controller in place of the LT3763. Noise immune
signal and ground via pairs are available to re-establish
the connections between DC2331A-A and twisted wire
pairs sensing the new primary controller.
A combination of capacitors is used at the DC2331A-A/
DC2331A-B power input:1210 ceramics, 2220 ceramics
in a metal frame, hybrids and bulk electrolytic capacitors.

2
DEMO MANUAL
DC2331A-A/DC2331A-B
Rev. 0
DESCRIPTION
The 2220 ceramics in a metal frame are robust and con-
venient but may be replaced with an equivalent amount
of 1210 capacitance to minimize electrical noise. The
hybrid and bulk electrolytic capacitors stabilize the input
power. A combination of ceramic and aluminum polymer
capacitors are used at the power output in accordance
with design practice for the LT3763 primary controller.
DC2331A-A/DC2331A-B includes filters and filter options
for inputs to the LT8550 in accordance with data sheet
recommendations. SHDN voltage, switching frequency
and LT8550 ILIM current limit levels can all be adjusted
by resistors or resistor jumpers. DC2331A-A/DC2331A-B
comes with a housekeeping circuit that provides an 11.5V
input voltage to the LT8550. The housekeeping circuit
reduces the power dissipation that would otherwise
occur at high input voltages in regulator transistor Q21.
DC2331A-A/DC2331A-B uses resistors to sense inductor
current, but can be configured for DCR sensing of induc-
tor current.
DC2331A-A/DC2331A-B retains the features of the
LT3763 primary controller including:
•two inputs for analog control of the output current
regulation level
• output current monitoring
• fault indication.
A resistor divider combined with the CTRL1 output cur-
rent regulation level control makes the LT3763 current
limit occur before the LT8550 current limit to ensure
that the power sections share equally during output cur-
rent overload conditions. A resistor-NTC voltage divider
combined with the CTRL2 control reduces output current
when the PCB temperature reaches approximately 100°C.
A sense resistor for input current can be added and used
for input current regulation and monitoring. DC2331A-A
has placeholders for optional components that will allow
a voltage applied to the CTLV terminal to make modest
changes to the output voltage.
A high level of available output power without a corre -
sponding high level of design complexity or loss of con-
troller features makes the LT8550 attractive for high cur-
rent DC bus and battery systems in commercial, industrial
and automotive settings. DC2331A-A/DC2331A-B features
the LT8550EUKG in a thermally enhanced 52-pin 7mm x
8mm QFN package. The LT8550 and LT3763 data sheets
must be read in conjunction with this demo manual to
properly use or modify DC2331A-A/DC2331A-B.
Design files for this circuit board are available.
PERFORMANCE SUMMARY
Specifications are at TA= 25°C
PARAMETER CONDITIONS MIN TYP MAX UNITS
Minimum Input Voltage, VIN 14 V
Maximum Input Voltage, VIN 56 V
Output Voltage, VOUT R17=12.1k, R18=107k, R19=909 11.6 12.4 V
Maximum Output Current, IOUT DC2331A-A 70 A
Maximum Output Current, IOUT DC2331A-A + DC2331A-B 126 A
Output Current Limit, IOUT DC2331A-A, R50 = 100k, R82 = 150k, RSNS5 = 0.0025 80 A
Output Current Limit, IOUT DC2331A-A + DC2331A-B, R50 = 100k, R82 = 150k, RSNS5 = 0.0025 144 A
Efficiency DC2331A-A, VIN = 24V, IOUT = 70A 97.50 %
Switching Frequency 250 kHz

3
DEMO MANUAL
DC2331A-A/DC2331A-B
Rev. 0
QUICK START PROCEDURE
To evaluate the performance of
• DC2331A-A without using the multi-chip (master-
slave) feature of the LT8550, follow steps 1–8 of the
procedure below
• DC2331A-AandDC2331A-Busingthemulti-chip(mas-
ter-slave) feature of the LT8550, follow steps9–17 of
the procedure below.
Follow Steps 1–8 to Use DC2331A-A Without the
Multi-Chip (Master-Slave) Feature:
1. Use a single DC2331A-A assembly
2. Prepare to use the SHDN terminal to control the
startup: Connect the SHDN terminal to GND using a
clip-onlead.
3. Set the MODE jumper JP4 to FLOAT if phase shedding
is desired or to GND if phase shedding is not desired.
4. Set the SYNC jumper JP5 to GND.
Figure1. Proper Equipment Setup for DC2331A-A
DC2548 F01
+
–
+
–
+
–
+
–
+
–
LOAD
12V
0A TO 70A
INPUT SUPPLY
0V TO 56V
60A
–
+
–
+
FOR START-UP

4
DEMO MANUAL
DC2331A-A/DC2331A-B
Rev. 0
QUICK START PROCEDURE
5. Set the phase selection jumpers as shown below:
JP3 GND
JP2 VCC
JP1 VCC
6. Connect the input power supply with power off, load
and meters as shown in Figure1, Proper Equipment
SetupforDC2331A-A.Seethenextsection,PowerCon-
nectionsBetween Assemblies and Optional Heatsinks,
for tips on how to connect input and output power.
7. After all connections are made, turn on the input
power and verify that the input voltage is between
14V and56V.
8. Remove the clip-on lead that connects the SHDN
terminal to GND. Verify that the output voltage is 12V.
See the note after step 17 below.
Follow Steps 9–17 to Use DC2331A-A and DC2331A-B
with the Multi-Chip (Master-Slave) Feature:
9. Use a single DC2331A-A assembly and one or more
DC2331A-B assemblies:
• DC2331A-A has one power section for the LT3763
primary controller and an additional four power
sections for its LT8550 which is configured as a
master.
• DC2331A-B does not have a primary controller, and
its LT8550 is configured as a slave with four power
sections.
NOTE: It is easiest to do steps 10–13 before the
SHDN terminals, ribbon cable and power wiring are
connected:
10. Set the MODE jumpers JP4:
•On the master assembly DC2331A-A, set JP4 to
FLOAT if phase shedding is desired or to GND if
phase shedding is not desired.
•On the slave assemblies DC2331A-B, set JP4 to
FLOAT.
11. Set the SYNC jumpers JP5:
•On the master assembly DC2331A-A, set JP5
toGND.
•On the slave assemblies DC2331A-B, set JP5
toSYNC_U1.
12. Set the phase selection jumpers for the master
DC2331A-Aasshownbelow, dependingon thenumber
of slave DC2331A-Bs:
DC2331A-A +
DC2331A-B
(OneSlave)
DC2331A-A + DC2331A-B and DC2331A-B
(Two Slaves)
DC2331A-A DC2331A-A
JP3 GND JP3 VCC
JP2 FLOAT JP2 VCC
JP1 FLOAT JP1 GND
13. Set the phase selection jumpers for the slave
DC2331A-B(s) as shown below, depending on the
number of slave DC2331A-Bs:
DC2331A-A +
DC2331A-B
(OneSlave)
DC2331A-A + DC2331A-B and DC2331A-B
(Two Slaves)
DC2331A-B First DC2331A-B Second DC2331A-B
JP3 GND JP3 GND JP3 GND
JP2 VCC JP2 VCC JP2 FLOAT
JP1 VCC JP1 VCC JP1 FLOAT
14. Prepareto usethe SHDN terminalto controlthestartup:
•Connect all the SHDN terminals together using
clip-on leads and then GND any of the SHDN ter-
minals with an additional clip-on lead.
15. In accordance with Figure2, Proper Equipment Setup
for DC2331A-A and DC2331A-B:
•Connect the ribbon cable provided with DC2331A-B
to interface the control logic between the mas-
ter DC2331A-A and a single or multiple slave
DC2331A-B(s). Each DC2331A-A/-B has two iden-
tical ribbon cable headers, so daisy-chain ribbon
cables are not required, even for systems with
multiple slave assemblies.

5
DEMO MANUAL
DC2331A-A/DC2331A-B
Rev. 0
QUICK START PROCEDURE
Figure2. Proper Equipment Setup for DC2331A-A and DC2331A-B
•Connect the input power supply with power off,
load and meters. See the next section, Power
Connections Between Assemblies and Optional
Heatsinks, for tips on how to connect input and
output power.
16. After all connections are made, turn on the input
power and verify that the input voltage is between
14V and56V.
17. Remove the clip-on lead that connects all the SHDN
terminals to GND. Verify that the output voltage is12V.
NOTE: If the output voltage is low, try startup again
using SHDN with the load disconnected. The load
may cause low output if some of the DC2331A power
sections are inadvertently disconnected and not able
to deliver power. It is possible the input supply may
current limit and cause DC2331A to have low output.
In more extreme cases it is possible that the load may
be set too high for DC2331A.
+
-
METERS
FOR ISMON
AND FAULT
+
-
VV
FOR
STARTUP
MASTER DC2331A-A
CONNECT
SHUTDOWN
TERMINALS
TOGETHER +
-A
LOAD
12V
0A – 130A
SLAVE DC2331A-B
+
-
V
RIBBON
CABLE
+
-A
INPUT
SUPPLY
0V – 56V
120A
+
-
+
-
V

6
DEMO MANUAL
DC2331A-A/DC2331A-B
Rev. 0
QUICK START PROCEDURE
Figure3. Efficiency and Power Loss—DC2331A-A
Figure4. 12VOUT at 70A VOUT Ripple with Infinite
Persist—DC2331A-A
Figure6. 24VIN Start-Up at No Load and Full Load—DC2331A-A
Figure5. 14VIN Start-Up at No Load and Full Load—DC2331A-A
Figure7. 56VIN Start-Up at No Load and Full Load—DC2331A-A
LOAD CURRENT (A)
0.1
1
10
100
0
10
20
30
40
50
60
70
80
90
100
1
10
100
1k
EFFICIENCY (%)
POWER LOSS (W)
DC2331A F03
EFFICIENCY
POWER LOSS
V
OUT
= 12V
fs = 250kHz
24V
IN–W/O SHEDDING
24V
IN–W/ SHEDDING
56V
IN–W/O SHEDDING
56V
IN–W/ SHEDDING
2µs/DIV
VOUT
20mV/DIV
VOUT
20mV/DIV
VOUT
10mV/DIV
DC2331A F04
56VIN
24VIN
14VIN
12VOUT AT 70A
1ms/DIV
SHDN
2V/DIV
VOUT
5V/DIV
VOUT
5V/DIV
DC2331A F05
14VIN
RLOAD = 0.165Ω
NO LOAD
1ms/DIV
SHDN
2V/DIV
VOUT
5V/DIV
VOUT
5V/DIV
DC2331A F06
24VIN
RLOAD = 0.165Ω
NO LOAD
1ms/DIV
SHDN
2V/DIV
VOUT
5V/DIV
VOUT
5V/DIV
DC2331A F07
56VIN
RLOAD = 0.165Ω
NO LOAD

7
DEMO MANUAL
DC2331A-A/DC2331A-B
Rev. 0
QUICK START PROCEDURE
Figure8. 56VIN, 12VOUT at 70A Thermal Image—DC2331A-A. Vertical Orientation with No Forced Air

8
DEMO MANUAL
DC2331A-A/DC2331A-B
Rev. 0
POWER CONNECTIONS BETWEEN ASSEMBLIES
AND OPTIONAL HEATSINKS
The power connections between master and slave
DC2331A assemblies—and between the DC2331A system
and the input supply or load—can be assembled using the
common components and hand tools shown in Figure9.
Figure9. Power Cabling is Assembled Using Common Components and Hand Tools

9
DEMO MANUAL
DC2331A-A/DC2331A-B
Rev. 0
POWER CONNECTIONS BETWEEN ASSEMBLIES
AND OPTIONAL HEATSINKS
The power connections between master and slave
DC2331A assemblies are important since unequal I*R
voltage drops in the power ground connections (VIN
ground in parallel with VOUT ground) between the assem-
blies can cause an offset voltage between the master and
slave assembly grounds. Consequently, the offset voltage
between master and slave grounds will cause undesired
current in the signal grounds of the control interface rib-
bon cable. The potential sources of the offset voltages
between DC2331A master and slave grounds, VDROP1
and VDROP2, are labeled in Figure10.
Figure10. Offset Voltages VDROP1 and VDROP2 Between DC2331A Master and Slave Grounds.
Make VDROP1 = VDROP2 to Prevent Undesired Current In the Signal Grounds of the Control Interface Ribbon Cable

10
DEMO MANUAL
DC2331A-A/DC2331A-B
Rev. 0
POWER CONNECTIONS BETWEEN ASSEMBLIES
AND OPTIONAL HEATSINKS
To minimize the offset voltage between assembly grounds,
the resistance of the ground power cabling should be
inversely proportional to the number of power sections
that connect through the ground cabling. In other words,
if the master assembly has five power sections and the
slave assembly has four power sections, then the resis-
tance of the master ground cabling should be 4/5 of the
slave ground cable resistance. Figure11 shows how to
make a ground cable that is 4/5 the resistance of a refer-
ence ground cable.
Figure11. The 4/5 R Ground Cable Is Made from a 4R and an R Ground Cable and Can Be Used
to Minimize the Offset Voltage Between Assembly Grounds

11
DEMO MANUAL
DC2331A-A/DC2331A-B
Rev. 0
POWER CONNECTIONS BETWEEN ASSEMBLIES
AND OPTIONAL HEATSINKS
Heatsinks as shown in Figure12 can be added to each
master and slave DC2331A assembly power section.
When used with a fan, the heatsinks will decrease
the thermal resistance between the DC2331A power
components and the ambient environment to increase
output power capability or lower component tempera-
tures. The DC2331A PCB design provides holes for
heatsink mounting.
Figure12. Heatsinks Can Be Added to DC2331A Assemblies for Improved Thermal Performance

12
DEMO MANUAL
DC2331A-A/DC2331A-B
Rev. 0
PARTS LIST
ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER
DC2331A-A Required Circuit Components
1 5 CIN1, CIN2, CIN3, CIN4, CIN5 CAP., X7S, 4.7µF, 100V, 10%, 1210 MURATA, GRJ32DC72A475KE11L
2 10 CIN6, CIN7, CIN8, CIN9, CIN10, CIN11, CIN12,
CIN13 CIN14, CIN15
CAP., X7R, 15µF, 100V, 10%, 2220
(J-LEAD)
MURATA, KRM55WR72A156MH01K
3 3 CIN17, CIN18, CIN19 CAP., ALUM., POLYMER, 47µF, 63V,
20%
SUN ELEC., 63HVH47M
4 5 COUT1, COUT2, COUT3, COUT4, COUT5 CAP., X7R, 22µF, 16V, 20%, 1210 MURATA, GRM32ER71C226MEA8L
5 10 COUT6, COUT7, COUT8, COUT9, COUT10,
COUT11, COUT12, COUT13, COUT14, COUT15
CAP., ALUM., 150µF, 16V, 20% PANASONIC, 16SVP150M
6 1 C1 CAP., X7R, 2.2µF, 100V, 20%, 1206 MURATA, GRM31CR72A225MA73L
7 3 C2, C25, C33 CAP., X5R, 2.2µF, 16V, 10%, 0603 MURATA, GRM188R61C225KE15D
8 1 C3 CAP., X5R, 10µF, 16V, 10%, 0603 MURATA, GRM188R61C106KAALD
9 10 C4, C5, C8, C9, C10, C11, CAP., X7R, 1000pF, 25V, 10%, 0603 MURATA, GRM188R71E102KA01D
C12, C13, C15, C35
10 1 C6 CAP., X7R, 100pF, 16V, 10%, 0603 AVX, 0603YC101KAT2A
11 4 C14, C27, C36, C57 CAP., X7R, 0.01µF, 16V, 10%, 0603 MURATA, GRM188R71C103KA01D
12 5 C17, C18, C19, C20, C21 CAP., X7R, 0.22µF, 16V, 10%, 0603 MURATA, GRM188R71C224KA01D
13 1 C22 CAP., NP0, 47pF, 50V, 5%, 0603 MURATA, GRM1885C1H470JA01D
14 1 C23 CAP., X7R, 1µF, 100V, 10%, 1206 MURATA, GRM31CR72A105KA01L
15 1 C24 CAP., X7R, 1µF, 16V, 10%, 0603 MURATA, GRM188R71C105KA12D
16 1 C26 CAP., NP0, 10pF, 50V, 5%, 0603 MURATA, GRM1885C1H100JA01D
17 1 C28 CAP., X7R, 2.2µF, 100V, 10%, 1210 MURATA, GRM32ER72A225KA35L
18 1 C29 CAP., X5R, 22µF, 16V, 20%, 0805 MURATA, GRM21BR61C226ME44L
19 1 C30 CAP., X7R, 0.033µF, 16V, 10%, 0603 MURATA, GRM188R71C333KA01D
20 1 C31 CAP., X7R, 4700pF, 16V, 10%, 0603 MURATA, GRM188R71C472KA01D
21 1 C32 CAP., X5R, 47µF, 16V, 10%, 1210 MURATA, GRM32ER61C476KE15K
22 2 C34, C62 CAP., X7R, 0.1µF, 16V, 10%, 0603 MURATA, GRM188R71C104KA01D
23 1 C60 CAP., NP0, 22pF, 50V, 5%, 0603 MURATA, GRM1885C1H220JA01D
24 7 D1, D2, D3, D4, D5, D6, D7 DIODE, SCHOTTKY, 100V, SOD323 NXP, BAT46WJ,115
25 1 D8 DIODE, 80V, SOD523 DIODES INC.,1N4448HWT-7
26 5 L1, L2, L3, L4, L5 IND., 6.8µH COILCRAFT, SER2915L-682KL
27 1 L6 IND., 47µH Wurth Elektronik, 744771147
28 20 Q1, Q2, Q3, Q4, Q5, Q6, Q7, Q8, Q9, Q10,
Q11, Q12, Q13, Q14, Q15, Q16, Q17, Q18,
Q19, Q20
XSTR., MOSFET, 60V, PG-TDSON-8 INFINEON, BSC100N06LS3
29 1 Q21 MOSFET, P-CH 100V 2.6A SOT223 DIODES INC., ZXMP10A18G
30 5 RSNS1, RSNS2, RSNS3, RSNS4, RSNS5 RES., SENSE, 0.0025Ω, 3W, 1%,
2512
NIC, NCSR300F2M50DTRGF
IRC/TT Electronics, ULRG32512R0025FLFSLT
Panasonic, ERJMP4PF2M5U

13
DEMO MANUAL
DC2331A-A/DC2331A-B
Rev. 0
ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER
31 2 R1, R50 RES., 100k, 1/10W, 1%, 0603 VISHAY, CRCW0603100KFKEA
32 1 R2 RES., 118k, 1/10W, 1%, 0603 VISHAY, CRCW0603118KFKEA
33 1 R3 RES., 13k, 1/10W, 1%, 0603 VISHAY, CRCW060313K0FKEA
34 2 R4, R98 RES., 47k, 1/10W, 5%, 0603 VISHAY, CRCW060347K0JNEA
35 6 R7, R11, R12, R13, R14, R15 RES., CHIP, 10Ω, 1/10W, 5%, 0603 VISHAY, CRCW060310R0JNEA
36 1 R8 RES., CHIP, 20Ω, 1/10W, 5%, 0603 VISHAY, CRCW060320R0JNEA
37 1 R10 RES., CHIP, 1Ω, 1/10W, 5%, 0603 VISHAY, CRCW06031R00JNEA
38 1 R16 RES., 210k, 1/10W, 1%, 0603 VISHAY, CRCW0603210KFKEA
39 1 R17 RES., 12.1k, 1/10W, 1%, 0603 VISHAY, CRCW060312K1FKEA
40 1 R18 RES., 107k, 1/10W, 1%, 0603 VISHAY, CRCW0603107KFKEA
41 1 R19 RES., 909Ω, 1/10W, 1%, 0603 VISHAY, CRCW0603909RFKEA
42 1 R20 RES, 10k, 1/10W, 5%, 0603 VISHAY, CRCW060310K0JNEA
43 3 R21, R22, R25 RES., 10Ω, 1/10W, 5%, 0603 VISHAY, CRCW060310R0JNEA
44 1 R27 RES., 19.6k, 1/10W, 1%, 0603 VISHAY, CRCW060319K6FKEA
45 1 R28 RES., 75k, 1/10W, 1%, 0603 VISHAY, CRCW060375K0FKEA
46 1 R29 RES., 1M, 1/10W, 1%, 0603 VISHAY, CRCW06031M00FKEA
47 1 R82 RES., 150k, 1/10W, 1%, 0603 VISHAY, CRCW0603150KFKEA
48 1 U1 I.C., LT8550, 52QFN ANALOG DEVICES, LT8550EUKG#PBF
49 1 U2 I.C., LED DRIVER, 28TSSOP ANALOG DEVICES, LT3763EFE#PBF
50 1 U3 I.C., REG., TSSOP28FE-EA ANALOG DEVICES, LT8631EFE#PBF
DC2331A-A Additional Demo Board Circuit Components
1 1 CIN16 CAP., ALUM., 470µF, 20%, 63V PANASONIC, EEV-FK1J471M
2 0 CIN20(OPT) CAP., ALUM., OPTION
3 1 C7 CAP., X7R, 1000pF, 25V, 10%, 0603 MURATA, GRM188R71E102KA01D
4 1 C16 CAP., ALUM., 10µF, 100V, 20% SUN ELEC., 100CE10BS
5 0 C37, C38, C39, C40, C41, C42, C43, C44, C45,
C46, C47, C48, C49, C50, C51, C52, C53, C54,
C55, C56, C58, C59(OPT)
CAP., OPTION, 0603
6 1 C61 CAP., X7R, 0.1µF,16V, 10%, 0603 MURATA, GRM188R71C104KA01D
7 0 Q22(OPT) TRAN., OPTION, SOT-23
8 1 RT1 THERMISTOR, NTC, 470KΩ, 0603 MURATA, NCP18WM474J03RB
9 15 R5, R6, R23, R34, R35, R36, R37, R38, R39,
R40, R41, R49, R53, R56, R62
RES., CHIP, 0Ω, 1/10W, 1%, 0603 VISHAY, CRCW06030000Z0EA
10 0 R9, R26, R30, R31, R32, R33, R42, R43, R44,
R45, R46, R47, R57, R58, R59, R60, R63,
R64, R65, R66, R67, R68, R69, R70, R71,
R76, R77, R78, R79, R80, R81, R84, R85,
R86, R87, R88, R89, R90, R91, R92, R93,
R94, R95, R102, R103, R104, R105, R107,
R108, R109, R110, R111, R112, R113, R114,
R115, R116, R117, R118, R119(OPT)
RES., OPTION, 0603
PARTS LIST

14
DEMO MANUAL
DC2331A-A/DC2331A-B
Rev. 0
PARTS LIST
ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER
11 2 R24, R52 RES., 47k, 1/10W, 5%, 0603 VISHAY, CRCW060347K0JNEA
12 1 R51 RES., 100k, 1/10W, 1%, 0603 VISHAY, CRCW0603100KFKEA
13 1 R48 RES., 133k, 1/10W, 1%, 0603 VISHAY, CRCW0603133KFKEA
14 1 R54 RES., 10k, 1/10W, 5%, 0603 VISHAY, CRCW060310K0JNEA
15 1 R55 RES., 15k, 1/10W, 1%, 0603 VISHAY, CRCW060315K0FKEA
16 1 R61 RES., 1M, 1/10W, 1%, 0603 VISHAY, CRCW06031M00FKEA
17 0 R72, R73, R74, R75(OPT) RES., OPTION, 0805
18 0 R83(OPT) RES., OPTION, 0805
19 0 R106(OPT) RES., OPTION, 2512
20 0 U4 (OPT) I.C., OPTION, OPAMP, 8MSOP ANALOG DEVICES, LT1636CMS8#PBF
DC2331A-A Hardware: For Demo Board Only
1 31 E1, E2, E3, E4, E5, E6, E7, E8, E9, E10, E11,
E12, E13, E14, E15, E16, E17, E18, E19, E20
E21, E22, E23, E24, E25, E26, E27, E28 E29,
E30, E31
TESTPOINT, TURRET, .061" MILL-MAX, 2308-2-00-80-00-00-07-0
2 2 JP1, JP2 HEADER 4 PIN 0.079 SINGLE ROW WURTH ELEKTRONIK, 62000411121
3 2 JP3, JP4 HEADER 3 PIN 0.079 SINGLE ROW WURTH ELEKTRONIK, 62000311121
4 1 JP5 HEADER 2X4 PIN, 0.079 WURTH ELEKTRONIK, 62000821121
5 5 XJP1, XJP2, XJP3, XJP4, XJP5 SHUNT, 2mm WURTH ELEKTRONIK, 60800213421
6 4 J1-J4 STUD, TEST PIN PEM, KFH-032-10ET
7 8 (J1-J4) NUT, BRASS NUTS # 10-32 ANY, 10-32M/S BR PL
8 12 (J1-J4) RING, LUG RING # 10 KEYSTONE, 8208
9 4 (J1-J4) WASHER, TIN PLATED BRASS ANY, #10EXT- BZ TN
10 2 J5, J6 HEADER, 2X7PIN, 0.079" MOLEX, 87831-1420
11 4 MH1-MH4 STAND-OFF, NYLON 1.0" WURTH ELEKTRONIK, 702939000

15
DEMO MANUAL
DC2331A-A/DC2331A-B
Rev. 0
PARTS LIST
ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER
DC2331A-B Required Circuit Components
1 4 CIN1, CIN2, CIN3, CIN5 CAP., X7S, 4.7µF, 100V, 10%, 1210 MURATA, GRJ32DC72A475KE11L
2 8 CIN6, CIN7, CIN8, CIN9, CIN10, CIN11, CIN14,
CIN15
CAP., X7R, 15µF, 100V, 10%, 2220
(J-LEAD)
MURATA, KRM55WR72A156MH01K
3 3 CIN17, CIN18, CIN19 CAP., ALUM., POLYMER, 47µF, 63V,
20%
SUN ELEC., 63HVH47M
4 4 COUT1, COUT2, COUT3, COUT4 CAP., X7R, 22µF, 16V, 20%, 1210 MURATA, GRM32ER71C226MEA8L
5 8 COUT6, COUT7, COUT8, COUT9, COUT10,
COUT11, COUT12, COUT13
CAP., ALUM., 150µF, 16V, 20% PANASONIC, 16SVP150M
6 1 C1 CAP., X7R, 2.2µF, 100V, 20%, 1206 MURATA, GRM31CR72A225MA73L
7 2 C2, C33 CAP., X5R, 2.2µF, 16V, 10%, 0603 MURATA, GRM188R61C225KE15D
8 1 C3 CAP., X5R, 10µF, 16V, 10%, 0603 MURATA, GRM188R61C106KAALD
9 7 C8, C9, C10, C11, C12, C13, C35 CAP., X7R, 1000pF, 25V, 10%, 0603 MURATA, GRM188R71E102KA01D
10 1 C6 CAP., X7R, 100pF, 16V, 10%, 0603 AVX, 0603YC101KAT2A
11 4 C17, C18, C19, C20 CAP., X7R, 0.22µF, 16V, 10%, 0603 MURATA, GRM188R71C224KA01D
12 1 C24 CAP., X7R, 1µF, 16V, 10%, 0603 MURATA, GRM188R71C105KA12D
13 1 C26 CAP., NP0, 10pF, 50V, 5%, 0603 MURATA, GRM1885C1H100JA01D
14 1 C27 CAP., X7R, 10nF, 16V, 10%, 0603 MURATA, GRM188R71C103KA01D
15 1 C28 CAP., X7R, 2.2µF, 100V, 10%, 1210 MURATA, GRM32ER72A225KA35L
16 1 C32 CAP., X5R, 47µF, 16V, 10%, 1210 MURATA, GRM32ER61C476KE15K
17 2 C34, C62 CAP., X7R, 0.1µF, 16V, 10%, 0603 MURATA, GRM188R71C104KA01D
18 1 C55 CAP., X7R, 220pF, 25V, 10%, 0603 AVX, 06033C221KAT4A
19 4 D1, D2, D3, D4 DIODE, SCHOTTKY, 100V, SOD323 NXP, BAT46WJ,115
20 4 L1, L2, L3, L4 IND., 6.8µH COILCRAFT, SER2915L-682KL
21 1 L6 IND., 47µH Wurth Elektronik, 744771147
22 16 Q1, Q2, Q3, Q4, Q5, Q6, Q7, Q8, Q9, Q10,
Q11, Q12, Q13, Q14, Q15, Q16
XSTR., MOSFET, 60V, PG-TDSON-8 INFINEON, BSC100N06LS3
23 1 Q21 MOSFET, P-CH 100V 2.6A SOT223 DIODES INC., ZXMP10A18G
24 4 RSNS1, RSNS2, RSNS3, RSNS4 RES., SENSE, 0.0025Ω, 3W, 1%,
2512
NIC, NCSR300F2M50DTRGF
IRC/TT ELECTRONICS, ULRG32512R0025FLFSLT
PANASONIC, ERJMP4PF2M5U
25 1 R2 RES., 118k, 1/10W, 1%, 0603 VISHAY, CRCW0603118KFKEA
26 1 R3 RES., 13k, 1/10W, 1%, 0603 VISHAY, CRCW060313K0FKEA
27 6 R7, R12, R13, R14, R15, R26 RES., CHIP, 10Ω, 1/10W, 5%, 0603 VISHAY, CRCW060310R0JNEA
28 1 R10 RES., CHIP, 1Ω, 1/10W, 5%, 0603 VISHAY, CRCW06031R00JNEA
29 1 R27 RES., 19.6k, 1/10W, 1%, 0603 VISHAY, CRCW060319K6FKEA
30 1 R28 RES., 75k, 1/10W, 1%, 0603 VISHAY, CRCW060375K0FKEA
31 1 R29 RES., 1M, 1/10W, 1%, 0603 VISHAY, CRCW06031M00FKEA
32 1 U1 I.C., LT8550, 52QFN ANALOG DEVICES, LT8550EUKG#PBF
33 1 U3 I.C., REG., TSSOP28FE-EA ANALOG DEVICES, LT8631EFE#PBF

16
DEMO MANUAL
DC2331A-A/DC2331A-B
Rev. 0
PARTS LIST
ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER
DC2331A-B Additional Demo Board Circuit Components
1 0 CIN4, COUT5(OPT) CAP., OPTION, 1210
2 0 CIN12, CIN13(OPT) CAP., OPTION, 2220 (J-LEAD)
3 1 CIN16 CAP., ALUM., 470µF, 20%, 63V PANASONIC, EEV-FK1J471M
4 0 CIN20(OPT) CAP., ALUM., OPTION
5 0 COUT14, COUT15(OPT) CAP., ALUM., OPTION
6 0 C4, C5, C14, C15, C21, C22, C25, C30, C31,
C36, C37, C38, C39, C40, C41, C42, C43, C44,
C45, C46, C47, C48, C49, C50, C51, C52, C53,
C54, C56, C57, C58, C59, C60, C61(OPT)
CAP., OPTION, 0603
7 1 C7 CAP., X7R, 1000pF, 25V, 10%, 0603 MURATA, GRM188R71E102KA01D
8 1 C16 CAP., ALUM., 10µF, 100V, 20% SUN ELEC., 100CE10BS
9 0 C23(OPT) CAP., OPTION, 1206
10 0 C29(OPT) CAP., OPTION, 0805
11 0 D5, D6, D7(OPT) DIODE, SCHOTTKY, OPTION, SOD323
12 0 D8(OPT) DIODE, OPTION, SOD523
13 0 L5(OPT) IND., OPTION
14 0 Q17, Q18, Q19, Q20(OPT) XSTR., MOSFET, OPTION,
PG-TDSON-8
15 0 Q22(OPT) MOSFET, OPTION, SOT223
16 0 RSNS5, R106(OPT) RES.,. OPTION, 2512
17 0 RT1(OPT) THERMISTOR, OPTION, 0603
18 0 R1, R4, R6, R9, R11, R16, R17, R18, R19,
R20, R21, R22, R24, R25, R33, R34, R35,
R36, R37, R38, R39, R40, R41, R42, R43,
R44, R45, R46, R47, R49, R50, R51, R52,
R53, R55, R56, R57, R58, R59, R60, R62,
R63, R64, R65, R66, R67, R68, R69, R70,
R71, R76, R77, R78, R79, R81, R82, R84,
R85, R86, R87, R88, R89, R90, R91, R92,
R93, R94, R98, R99, R100, R101, R102,
R103, R104, R105, R108, R109, R110, R111,
R112, R113, R114, R115, R116, R117, R118,
R119(OPT)
RES., OPTION, 0603
19 11 R3, R5, R8, R30, R31, R32, R80, R95, R96,
R97, R107
RES., CHIP, 0Ω, 1/10W, 1%, 0603 VISHAY, CRCW06030000Z0EA
20 1 R48 RES., 133k, 1/10W, 1%, 0603 VISHAY, CRCW0603133KFKEA
21 1 R54 RES., 10k, 1/10W, 5%, 0603 VISHAY, CRCW060310K0JNEA
22 1 R61 RES., 1M, 1/10W, 1%, 0603 VISHAY, CRCW06031M00FKEA
23 0 R72, R73, R74, R75, RES., OPTION, 0805
R83(OPT)

17
DEMO MANUAL
DC2331A-A/DC2331A-B
Rev. 0
PARTS LIST
ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER
DC2331A-B Hardware: For Demo Board Only
1 21 E1, E2, E3, E4, E5, E6, E7, E8, E9, E10, E14,
E15, E19, E21, E22, E23, E24, E27, E28, E29,
E30
TESTPOINT, TURRET, .061" MILL-MAX, 2308-2-00-80-00-00-07-0
2 0 E11, E12, E13, E16, E17, E18, E20, E25, E26,
E31(OPT)
TESTPOINT, TURRET, .061" MILL-MAX, 2308-2-00-80-00-00-07-0
3 2 JP1, JP2 HEADER 4 PIN 0.079 SINGLE ROW WURTH ELEKTRONIK, 62000411121
4 2 JP3, JP4 HEADER 3 PIN 0.079 SINGLE ROW WURTH ELEKTRONIK, 62000311121
5 1 JP5 HEADER 2X4 PIN, 0.079 WURTH ELEKTRONIK, 62000821121
6 5 XJP1, XJP2, XJP3, XJP4, XJP5 SHUNT, 2mm WURTH ELEKTRONIK, 60800213421
7 4 J1-J4 STUD, TEST PIN PEM, KFH-032-10ET
8 8 (J1-J4) NUT, BRASS NUTS # 10-32 ANY, 10-32M/S BR PL
9 12 (J1-J4) RING, LUG RING # 10 KEYSTONE, 8208
10 4 (J1-J4) WASHER, TIN PLATED BRASS ANY, #10EXT- BZ TN
11 2 J5, J6 HEADER, 2X7PIN, 0.079" MOLEX, 87831-1420
12 4 MH1-MH4 STAND-OFF, NYLON 1.0" WURTH ELEKTRONIK, 702939000
13 1 CABLE ASSY., 8" STRIP MMT PRECISION CORP., CA-2440

18
DEMO MANUAL
DC2331A-A/DC2331A-B
Rev. 0
LT3763
LT8550 PRIMARY CONTROLLER
OPTIONAL DCR SENSE
[1.]
[2.]
[3.]
[2.]
[2.] [2.]
_____
VIN
SYNC
TG
BOOST
BG
EN/UVLO
INTVCC SENSE+ SENSE- SW
REGSNS
ISN ISP
ENOUT
BGSH
TGSR
TGSH
TGSL
CLK1
SHDN
ISN_DCR ISP_DCR SENSE+_DCR
SENSE-_DCR
VOUT
CLK1
TGBUF
BGBUF
BGBUF/BGSH
TGBUF/TGSH
CLK1/SYNC_U1
SYNC_U1
FAULT
ISMON
IVINMON
CTRL1 CTRL2 CTLV
CLK2 MODE REGSNS
TGBUF/TGSH BGBUF/BGSH
ENOUT
TGBUF/TGSH BGBUF/BGSH
BGBUF/BGSH TGBUF/TGSH
CLK1/SYNC_U1
CLK1/SYNC_U1
IAMPP
IAMPN
CLK1/SYNC_U1
+
CIN17
47uF
63V
63HVH47M
E4
IAMPP
E6
MODE
R35
0
E28 BGBUF/BGSH
TP15
TGSH
R53
0
TP17 BG
E7
CLK2
E14
GND
TP29
GND
E5
IAMPN
R32
OPT
J2
GND
R41
0
TP7
TGSR
E17 FAULT
_____
TP4
SENSE+
J6
7
7
9
9
1
122
66 44
10 10
5
5
11
11 12 12
14 14
13
13
3
3
88
E30 CLK1/SYNC_U1
E8
SHDN
____
E31 CTLV
E26 SYNC
R36
0
TP6
TGBUF
+
CIN16 470uF
63V
EEV-FK1J471M
R49
0
R39
0
E13
EN/UVLO
E29 TGBUF/TGSH
+
CIN20
OPT
R31
OPT
E16 ISMON
TP10
BGSH
TP14
SENSE-
J4
GND
TP26
GND
TP12
ENOUT
TP21
CLK1
R40
0
TP18
BGBUF
+
CIN18
47uF
63V
63HVH47M
R33 OPT
J5
7
7
9
9
1
122
66 44
10 10
5
5
11
11 12 12
14 14
13
13
3
3
88
R102 OPT
TP25
ISP
R37
0
TP20
SENSE+_DCR
E10
VO-
J1
VIN
14V - 56V
+
CIN19
47uF
63V
63HVH47M
E25 GND
R103 OPT
TP28
GND
J3
VOUT
12V 70A
R34
0
TP27
GND
TP5
ISN
TP3
SENSE-_DCR
C53
OPT
E27 ENOUT
E2
VIN-
R38
0
E20 GND
E9
VO+
E18 IVINMON
E19
SYNC_U1
TP22 INTVCC
E1
VIN+
E15 GND
E22
GND
TP9
ISN_DCR
E24 GND
R62
0E3 GND
R63 OPT
TP24 SW
TP19
ISP_DCR
E23 GND
C58
OPT
TP11
CLK1
TP23 TG
TP13
REGSNS
R30
OPT
R56
0
E21 REGSNS
E11 CTRL2
TP16
TGSL
TP8 BOOST
E12 CTRL1
CLK2
REGSNS ENOUT
MODE
IAMPPIAMPN
SCHEMATIC DIAGRAM

19
DEMO MANUAL
DC2331A-A/DC2331A-B
Rev. 0
250kHz
[4.]
[2.]
[2.]
[2.]
[2.]
[2.]
[2.]
[2.]
[2.]
[2.]
[2.]
[2.]
[5.]
SYNC_U1
GND
RSYNC
VCC
[2.]
[2.]
VIN
VIN
TGSH TGSL
REGSNS
TGSR
ISN
ISP
BGSH
CLK1
REG
SHDN ENOUT
TGBUF BGBUF
CLK2
IAMPN IAMPP
ISP_DCR ISN_DCR
MODE
VCC VCC VCC
VCC
SYNC_U1 VCC
C2 2.2uF
R107
OPT
C6
100pF
D7 BAT46WJ
12
C4 1nF
JP4
MODE
FLOAT
GND
1 3 2
JP1
PHS1
FLOAT VCC
GND
1 2 3 4
C8
1nF
R80 OPT
R96
OPT
C35 1nF
R105 OPT
C36 10nF
C3
10uF
R26
10
R8
20
C9
1nF
R1
100k 1%
R43 OPT
R3
13k
1%
R11
10
JP2
PHS2
FLOAT VCC GND
1 2 3 4
R42
OPT
C48 OPT
R4
47k
C51
OPT
R81 OPT
JP3
PHS3
VCC GND
1 3 2
C52
OPT
R2
118k
1%
JP5
SYNC
1 2 3 4 5 6 7 8
R6
0
LT8550EUKG U1A
REGSNS
40
REGIS
47
REGDRV
48
REG
3
VCC
29
ILIM
27
MODE
30
IAMPP
33
IAMPN
32
ISP
34
ISN
35
TGSR
17
TGSH
18
TGSL
19
TGBUF 13
BGBUF 12
BGSH 22
CLK1 21 CLK2 20
SYNC 23
RT/MS 26
PHS1 25 PHS2 24 PHS3 41
SHDN 31
ENOUT 28
NC
42
GND
53
R23
0
C27
0.01uF
C55 220pF
R7
10
C7 1nF
R10
1
R48
133k
C56
OPT
C54 OPT
Q21
ZXMP10A18G 1
234
R97 OPT
R5
0
C5
1nF
R95
OPT
D6
BAT46WJ
1 2
VCC
VCC
VCC
SCHEMATIC DIAGRAM

20
DEMO MANUAL
DC2331A-A/DC2331A-B
Rev. 0
VIN
VIN
11.5V
REG
REG
VOUT VOUT
ISP1_DCR ISN1_DCR ISN1_DCR
ISP1_DCR
ISP2_DCR ISN2_DCR
ISN2_DCR ISP2_DCR
Q5
BSC100N06LS3
3
2
1
4
5
R72 OPT 0805
C50
OPT
+
COUT13 150uF 16V
16SVP150M
Q7 BSC100N06LS3
3
2
1
4
5
C42 OPT
RSNS1 0.0025 2512 1%
R66 OPT
R78
OPT
CIN9 15uF 100V KRM55WR
L1
6.8uH
SER2915L-682KL
Q6
BSC100N06LS3
3
2
1
4
5
CIN1 4.7uF 1210 100V
R13 10
C49
OPT
D2 BAT46WJ
1 2
Q4 BSC100N06LS3
3
2
1
4
5
R60 OPT
R73 OPT 0805
C38 OPT
C12 1000pF
C19
0.22uF
COUT1 22uF 16V X7R
1210
TP2
C44 OPT
R86
OPT
R79
OPT
R12 10
CIN8 15uF 100V KRM55WR
CIN6 15uF 2220 100V KRM55WR
Q8 BSC100N06LS3
3
2
1
4
5
R45 OPT
COUT4 22uF 16V X7R
1210
R87
OPT
R69
OPT
CIN5 4.7uF 1210 100V
D1
BAT46WJ
1 2
C40 OPT
R68 OPT
L2
6.8uH
SER2915L-682KL
LT8550EUKG U1B
VIN
49 BST1 14
TG1 15
SW1 16
BG1 11
ISP1 44
ISN1 43
BST2 7
TG2 8
SW2 9
BG2 10
ISP2 36
ISN2 37
R88
OPT
+
COUT10 150uF 16V 16SVP150M
Q2
BSC100N06LS3
3
2
1
4
5
R89
OPT
C1 2.2uF
1206 100V
R46 OPT
R58
OPT
Q3 BSC100N06LS3
3
2
1
4
5
Q1
BSC100N06LS3
3
2
1
4
5
R67
OPT
+
COUT6 150uF 16V 16SVP150M
R90 OPT
RSNS2 0.0025 2512 1%
C17
0.22uF
+
COUT7 150uF 16V
16SVP150M
CIN7 15uF 2220 100V KRM55WR
C13 1000pF
ISP1
ISN1
ISP2
ISN2
ISP2
ISP1 ISN1
ISN2
SCHEMATIC DIAGRAM