DC2229A - Demo Manual

DEMO MANUAL DC2229A
DC2229A-A: LTC3877
DC2229A-B: LTC3877/LTC3874
High Current Step-Down Converter
Description
Demonstration circuits 2229A-A and 2229A-B feature the
LTC®3877 in two high output current, high efficiency, VID
programmed step-down converters with sub-mΩ DCR
sensing. For both converters, the input voltage range is
6V to 14V and the switching frequency is 400kHz.
The DC2229A-A provides two outputs. VOUT1 is VID
programmable from 0.6V to 1.23V and VOUT2 is set for
1.5V. Both rails have a maximum load current of 30A. The
DC2229A-B assembly is a four phase converter providing
a VID programmable output of 0.6V to 1.23V with a maximum load current of 120A. Phases 1 and 2 are controlled
by the LTC3877 and phases 3 and 4 are controlled by the
LTC3874 slave controller.
The demo board uses 0.25µH inductors with a DCR value of
0.325mΩ. The LTC3877 and LTC3874 employ a proprietary
sub-mΩ DCR sensing architecture which enhances the
signal to provide accurate control of the inductor current.
The low DCR inductors, along with the use of low Qg/low
RDS(ON) discrete FETs and strong gate drivers provides
high efficiency for high output current supplies. The full
load efficiency is 90.3%, as seen on the 1.5V rail of the
LTC3877 dual output converter (DC2229A-A assembly)
with an input voltage of 12V.
Additional features of this demo board include:
n
Remote sensing
n
PLLIN and CLKOUT pins
n
PGOOD, RUN and TK/SS pins
n
Optional resistors to tie two or more phases together
n
Optional footprints for BSG0811 dual channel MOSFETs
n
n
Optional NTC network on the ITEMP pin of the LTC3877
for less current limit variation over temperature
Dynamic load circuit
The demo board uses a high density, two-sided drop-in
layout. The core components for each dual phase section
consists of MOSFETs, inductors, ceramic CIN, ceramic
COUT on the top layer and the control circuit on the bottom,
resides in a 1.3" x 1.3" area of the board.
The LTC3877 and LTC3874 data sheets provide a complete
description of the IC operation and application information. These data sheets must be read in conjunction with
the quick start guide.
Design files for this circuit board are available at
http://www.linear.com/demo/DC2229A
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.
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1
DEMO MANUAL DC2229A
Performance Summary
Table 1. DC2229A-A Performance Summary (TA = 25°C), No Airflow
PARAMETER
CONDITIONS
Minimum Input Voltage
VALUES
6V
Maximum Input Voltage
14V
Output Voltage VOUT1, VID programmed
IOUT1 = 0A to 30A, VIN = 6V to 14V
VID0–VID5 = L
VID0, VID5 = L, VID1–VID4 = H
VID0–VID5 = H
0.6V ± 1%
0.9V ± 1%
1.23V ± 1%
Output Voltage VOUT2
IOUT2 = 0A to 30A, VIN = 6V to 14V
1.5V ± 1.5%
VOUT1 Maximum Output Current, IOUT1
VIN = 6V to 14V
30A
VOUT2 Maximum Output Current, IOUT2
VIN = 6V to 14V
30A
Nominal Switching Frequency
400kHz
Efficiency
VOUT1 = 1.2V, IOUT1 = 30A, VIN = 12V
89.1% typical
See Figures 3 to 5
VOUT2 = 1.5V, IOUT2 = 30A, VIN = 12V
90.3% typical
Table 2. DC2229A-B Performance Summary (TA = 25°C), No Airflow
PARAMETER
CONDITIONS
VALUES
Minimum Input Voltage
6V
Maximum Input Voltage
14V
Output Voltage VOUT, VID programmed
IOUT1 = 0A to 120A, VIN = 6V to 14V
VID0–VID5 = L
VID0, VID5 = L, VID1–VID4 = H
VID0–VID5 = H
0.6V ± 1%
0.9V ± 1%
1.23V ± 1%
VOUT Maximum Output Current, IOUT
VIN = 6V to 14V
120A
Nominal Switching Frequency
Efficiency, See Figure 6
2
400kHz
VOUT = 1.2V, IOUT1 = 120A, VIN = 12V
88.8% typical
dc2229af
DEMO MANUAL DC2229A
Quick Start Procedure
Demonstration circuits 2229A-A and 2229A-B are easy to
set up to evaluate the performance of the LTC3877 and
LTC3874. Please refer to Figure 1 (DC2229A-A assembly)
and Figure 2 (DC2229A-B assembly) for the 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 or Figure 2. Preset the load
to 0A and VIN supply to be 0V. For both assemblies,
place the jumpers in the following positions:
JP10
RUN
ON
JP8
MODE
FCM
JP7
VID_EN
H
JP1, JP6
VID0,VID5
L
JP2-JP5
VID1–VID4
H
2)Increase the input voltage to 12V.
3)Check the output voltage.
6)Adjust the input voltage and load current to the desired
levels within their limits and observe the regulation,
output ripple, load step response, efficiency and other
parameters.
7)Adjust VOUT1 with VID0–VID5 at JP1–JP6. Refer to the
data sheet for the VID programming table.
NOTE 1: To monitor the output voltage ripple, use the
BNC connectors labeled VOUT1 and VOUT2. VOUT1 is at
J9 and VOUT2 is at J10.
NOTE 2: Do not connect load between the VO1_SNS+
and VO1_SNS– turrets or between the VO2_SNS+ and
VO2_SNS– turrets. This could damage the converter.
Only apply load across the stud connectors on the edge
of the board which are located at J3 through J8.
Dynamic Load Circuit (Optional)
Demonstration circuit 2229A provides a simple load step
circuit consisting of a MOSFET and sense resistor for VOUT1
and VOUT2. To apply a load step, follow the steps below.
a) For the LTC3877 dual output converter (2229A-A assembly), VOUT1 should be 0.9V ± 1%. VOUT2 should be
1.5V ±1.5%.
1)Pre-set the amplitude of a pulse generator to 0.0V and
the duty cycle to 5% or less.
b)For the LTC3877/LTC3874 four phase converter
(DC2229A-B assembly), VOUT1 should be 0.9V ± 1%.
2)To monitor the load step current, connect a scope probe
across the ISTEP+/– turrets for that rail.
4)Next, apply full load and re-measure VOUT.
3)Connect the output of the pulse generator to the PULSE
GEN turret for the rail under test and connect the return
to the adjacent GND turret.
a) For the LTC3877 dual output converter (DC2229A-A
assembly), the full load current is 30A for VOUT1 and
30A for VOUT2.
b)For the LTC3877/LTC3874 four phase converter
(DC2229A-B assembly), the full load current is 120A.
5)Re-check regulation.
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 2mV/A.
5)For the four-phase LTC3877/LTC3874 converter
(DC2229A-B assembly), either load step circuit can be
used.
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3
DEMO MANUAL DC2229A
Quick Start Procedure
–
VOUT1
LOAD
+
+
VOUT2
LOAD
–
IOUT2
IOUT1
+
–
VOUT1*
+
–
VOUT2*
DC2229 F01
IIN
* MONITOR THE OUTPUT VOLTAGE ACROSS EITHER COUT1
OR COUT6 FOR ACCURATE EFFICIENCY MEASUREMENTS
+
VIN
–
VIN
SUPPLY
+
–
Figure 1. Proper Measurement Equipment Setup for the Dual Output LTC3877 Converter (DC2229A-A Assembly)
4
dc2229af
DEMO MANUAL DC2229A
Quick Start Procedure
+
LOAD
–
IOUT
+
–
VOUT
IIN
+
VIN
–
DC2229 F02
VIN
SUPPLY
+
–
Figure 2. Proper Measurement Equipment Setup for the Four Phase LTC3877/LTC3874 Converter (DC2229A-B Assembly)
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5
DEMO MANUAL DC2229A
Quick Start Procedure
95
90
EFFICIENCY (%)
90
EFFICIENCY (%)
95
VIN = 12V
FSW = 400kHz
FCM
85
80
VOUT = 1.2V
VOUT = 1.0V
VOUT = 0.9V
VOUT = 0.6V
75
70
0
5
10
20
15
25
LOAD CURRENT (A)
30
85
80
75
70
35
FCM
FSW = 400kHz
0
5
10
20
15
25
LOAD CURRENT (A)
dc2229 F03
Figure 3. Efficiency Curves for VOUT1 of the LTC3877
Dual Output Converter (DC2229A-A Assembly) Across the
Programmable VID Range. VIN = 12V
95
80
75
70
95
0
5
10
20
15
25
LOAD CURRENT (A)
30
VOUT1 = 12V
FSW = 400kHz
FCM
90
85
80
VOUT = 1.2V
VOUT = 1.0V
VOUT = 0.9V
VOUT = 0.6V
75
VIN = 7V
VIN = 12V
VIN = 14V
35
dc2229 F05
Figure 5. Efficiency Curves for VOUT1 of the LTC3877 Dual
Output Converter (DC2229A-A Assembly) as the Input
Voltage Is Varied. VOUT1 is set to 1.0V
6
Figure 4. Efficiency Curves for the 1.5V Rail at VOUT2
on the LTC3877 Dual Output Converter (DC2229A-A
Assembly) at VIN = 12V
EFFICIENCY (%)
EFFICIENCY (%)
85
35
dc2229 F04
VOUT1 = 1.0V
FSW = 400kHz
FCM
90
30
70
0
5
10
20
15
25
LOAD CURRENT (A)
30
35
dc2229 F06
Figure 6. Efficiency Curves for VOUT1 of the Four Phase
LTC3877/LTC3874 Converter (DC2229A-B Assembly)
Across the VID Programming Range. VIN = 12V
dc2229af
DEMO MANUAL DC2229A
Quick Start Procedure
VOUT = 0.9V
VIN = 12V
VOUT1
50mV/DIV
119mV
30A
LOAD STEP
5A/DIV
15A
50µs/DIV
DC2229 F07
Figure 7. Load Step Response of VOUT1 on the Dual Output LTC3877 Converter (DC2229A-A Assembly)
VIDEN = L, VID0,5 = L, VID1-4 = H
COUT:3x Panasonic EEFSX0E331ER (330µF, 2.5V, 9mΩ) ||
2x Murata GRM31CR60G227ME11L (220µF, 4V, X5R, 1206)
FSW: 400kHz
VOUT = 1.5V
VIN = 12V
VOUT2
50mV/DIV
106mV
30A
LOAD STEP
5A/DIV
15A
50µs/DIV
DC2229 F08
Figure 8. Load Step Response of VOUT2 on the Dual Output LTC3877 Converter (DC2229A-A Assembly)
COUT:3x Panasonic EEFSX0E331ER (330µF, 2.5V, 9mΩ) ||
2x Murata GRM31CR60G227ME11L (220µF, 4V, X5R, 1206)
FSW: 400kHz
VOUT = 0.9V
VIN = 12V
VOUT
50mV/DIV
91mV
120A
LOAD STEP
10A/DIV
90A
50µs/DIV
DC2229 F09
Figure 9. Load Step Response of the Four Phase LTC3877/LTC3874 Converter (DC2229A-B Assembly)
VIDEN = L, VID0,5 = L, VID1-4 = H
COUT:3x Panasonic EEFSX0E331ER (330µF, 2.5V, 9mΩ) ||
2x Murata GRM31CR60G227ME11L (220µF, 4V, X5R, 1206)
FSW: 400kHz
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7
DEMO MANUAL DC2229A
Parts List
ITEM
QTY
DC2155A-A
REFERENCE
PART DESCRIPTION
MANUFACTURER/PART NUMBER
CAP, 0.1µF, X7R, 16V, 10%, 0603
TDK, C1608X7R1C104K
DC2229A-A Required Circuit Components
1
6
C1, C4, C6, C8, C14, C15
2
1
C10
CAP, 3.3nF, X5R, 25V, 10%, 0603
TDK, C0603X5R1E332K
3
1
C11
CAP, 4.7µF, X5R, 16V, 10%, 0805
AVX, 0805YD475KAT2A
4
1
C12
CAP, 47pF, COG, 50V, 5%, 0603
AVX, 06035A470JAT2A
5
1
C13
CAP, 2.2nF, X7R, 25V, 10%, 0603
AVX, 06033C222KAT2A
6
4
C2, C3, C18, C19
CAP, 0.22µF, X7R, 16V, 10%, 0603
AVX, 0603YC224KAT2A
7
2
C5, C17
CAP, 10µF, X5R, 16V, 10%, 0805
AVX, 0805YD106KAT2A
8
1
C9
CAP, 100pF, C0G, 50V, 5% 0603
AVX, 06035A101JAT2A
9
4
CIN1, CIN2, CIN3, CIN4
CAP, 22µF, X5R, 16V, 10%, 1210
MURATA, GRM32ER61C226KE20L
10
2
CIN9, CIN10
CAP, OS-CON, 180µF, 16V, 20%, SVP-F8
PANASONIC, 16SVP180MX
11
4
COUT1, COUT2, COUT6, COUT7
CAP, 220µF, X5R, 4V, 10%, 1206
MURATA, GRM31CR60G227ME11L
12
6
COUT3–COUT5, COUT8–COUT10
CAP, SPECIALTY POLYMER, 330µF, 2.5V, 7343 PANASONIC, EEFSX0E331ER
13
2
D1, D2
DIODE, SCHOTTKY, SOD-323
CENTRAL SEMI, CMDSH-3TR
14
2
L1, L2
INDUCTOR, 0.25µH
WURTH ELEKTRONIK, 744301025
15
2
Q1, Q3
MOSFET N-CH 25V 39A TDSON-8
INFINEON, BSC050NE2LS
16
2
Q2, Q4
MOSFET N-CH 25V 38A TDSON-8
INFINEON, BSC010NE2LSI
17
2
R12, R28
RES, 665Ω, 1/10W, 1%, 0603
NIC, NRC06F6650TRF
18
1
R15
RES, 2.2Ω, 1/10W, 1%, 0603
NIC, NRC06F2R20TRF
19
1
R16
RES, 20k, 1/10W, 1%, 0603
NIC, NRC06F2002TRF
20
5
R17, R37, R70, R72, R78
RES, 10k, 1/10W, 1%, 0603
NIC, NRC06F1002TRF
21
1
R18
RES, 4.75k, 1/10W, 1%, 0603
VISHAY, CRCW06034K75FKEA
22
1
R19
RES, 10.7k, 1/10W, 1%, 0603
VISHAY, CRCW060310K7FKEA
23
1
R21
RES, 15k, 1/10W, 1%, 0603
NIC, NRC06F1502TRF
24
1
R24
RES, 10k, 1/10W, 1%, 0603
NIC, NRC06F1002TRF
25
1
R27
RES, 88.7k, 1/10W, 1%, 0603
VISHAY, CRCW060388K7FKEA
26
1
R36
RES, 30.1k, 1/10W, 1%, 0603
VISHAY, CRCW060330K1FKEA
27
7
R4, R14, R20, R31, R74, R65, R82
RES, CHIP, 0Ω , 0603
NIC, NRC06ZOTRF
28
1
R76
RES, 34.8k, 1/10W, 1%, 0603
VISHAY, CRCW060334K8FKEA
29
2
R8, R26
RES, 3.32k, 1/10W, 1%, 0603
NIC, NRC06F3321TRF
30
4
R9, R10, R33, R34
RES, 10Ω, 1/10W, 1%, 0603
NIC, NRC06F10R0TRF
31
1
U1
IC, STEP-DOWN CONVERTER
LINEAR TECH, LTC3877EUK#PBF
Dynamic Load Circuits
1
2
Q21, Q22
MOSFET N-CH 30V 80A D2PAK
VISHAY, SUM60N02-3M9P-E3
2
2
R70, R72
RES, 10k, 1/10W, 1%, 0603
NIC, NRC06F1002TRF
3
2
R71, R73
RES, 0.002Ω, 1%, 1/2W, 2010
VISHAY, WSL20102L000FEA
8
dc2229af
DEMO MANUAL DC2229A
Parts List
ITEM
QTY
DC2155A-A
REFERENCE
PART DESCRIPTION
MANUFACTURER/PART NUMBER
Additional Demo Board Circuit Components
1
0
C25
CAP, 0805, OPTIONAL
2
0
C7, C16, C20, C21, C22, C23, C24, C26, C27,
C28, C29, C32, C34
CAP, 0603, OPTIONAL
3
0
C33
CAP, 1206, OPTIONAL
CIN11
CAP, OS-CON, SVP-F8
4
5
0
CIN5–CIN8, CIN12–CIN19
CAP, 1210, OPTIONAL
6
0
COUT11, COUT12, COUT16, COUT17
CAP, 1206, OPTIONAL
7
0
COUT13–COUT15, COUT18–COUT20,
COUT21–COUT44
POSCAP, 7343, OPTIONAL
D3, D4
DIODE, SOD-323
J7, J8
STUD, TESTPIN, OPTIONAL
PEM, KFH-032-10
L3, L4
INDUCTOR
WURTH ELEKTRONIK, 744301025
0
Q17–Q20
MOSFET, DUAL N-CHANNEL OPTIONAL
INFINEON, BSG0811ND
Q23
MOSFET, N-CHANNEL SOT-23 OPTIONAL
13
0
Q5–Q16
MOSFET, N-CHANNEL, POWERPAK OPTIONAL
14
2
R13, R22
RES, CHIP, 0Ω , 0603
8
9
0
10
11
12
NIC, NRC06ZOTRF
15
1
R25
RES, 10k, 1/10W, 1%, 0603
NIC, NRC06F1002TRF
16
2
R35, R38
RES., 100k, 1/10W, 1%, 0603
NIC, NRC06F1003TRF
17
0
R1–R3, R5–R7, R11, R23, R29, R30, R32,
R39–R58, R63, R64, R66–R68, R69, R75,
R77, R80, R81, RN1, RN2
RES, 0603, OPTIONAL
18
0
R79
RES, 0805, OPTIONAL
19
0
R59, R60, R63, R64
RES, 1225, OPTIONAL
20
0
U2
IC, STEP-DOWN CONTROLLER, SLAVE
LINEAR TECH., LTC3874IUFD#PBF
21
0
U3
IC, COMPARATOR
LINEAR TECH., LT6703IDC-3#PBF
Hardware: For Demo Board Only
1
26
E1–E26
TESTPOINT, TURRET, 0.094"
MILL-MAX, 2503-2-00-80-00-00-07-0
2
6
J1–J6
RING, LUG #10
KEYSTONE, 8205, #10
3
6
J1–J6
STUD, TEST PIN
PEM, KFH-032-10
4
6
J1–J6
WASHER, TIN PLATED BRASS
ANY #10
5
12
J1–J6 X (2)
NUT, BRASS 10-32
ANY #10-32
6
2
J9, J10
CONN, BNC 5PINS
CONNEX, 112404
7
8
JP1–JP7, JP10
HEADER, 3-PIN 0.079 SINGLE ROW
SULLINS, NRPN031PAEN-RC
8
2
JP8, JP9
HEADER, 4-PIN, 2mm SINGLE ROW
SULLINS, NRPN041PAEN-RC
dc2229af
9
DEMO MANUAL DC2229A
Parts List
ITEM
QTY
DC2155A-B
REFERENCE
PART DESCRIPTION
MANUFACTURER/PART NUMBER
DC2229A-B Required Circuit Components
1
4
CIN1, CIN2, CIN3, CIN4
CAP, 22µF, X5R, 16V, 10%, 1210
MURATA., GRM32ER61C226KE20L
2
2
CIN9, CIN10
CAP, OS-CON, 180µF, 16V, 20%, SVP-F8
PANASONIC, 16SVP180MX
3
4
COUT1, COUT2, COUT6, COUT7
CAP, 220µF, X5R, 4V, 10%, 1206
MURATA., GRM31CR60G227ME11L
4
6
COUT3–COUT5, COUT8–COUT10
CAP, POSCAP, 330µF, 2.5V, 7343
PANASONIC, EEFSX0E331ER
5
5
C1, C4, C6, C8, C14
CAP, 0.1µF, X7R, 16V, 10%, 0603
TDK, C1608X7R1C104K
6
4
C2, C3, C18, C19
CAP, 0.22µF, X7R, 16V, 10%, 0603
AVX, 0603YC224KAT2A
7
2
C5, C17
CAP, 10µF, X5R, 16V, 10%, 0805
AVX, 0805YD106KAT2A
8
1
C9
CAP, 100pF, C0G, 50V, 5%, 0603
AVX, 06035A101JAT2A
9
1
C10
CAP, 3.3nF, X5R, 25V, 10%, 0603
TDK, C0603X5R1E332K
10
1
C11
CAP, 4.7µF, X5R, 16V, 10%, 0805
AVX , 0805YD475KAT2A
11
2
D1, D2
DIODE, SCHOTTKY, SOD-323
CENTRAL SEMI., CMDSH-3TR
12
2
L1, L2
INDUCTOR, 0.25µH
WURTH ELEKTRONIK, 744301025
13
2
Q1, Q3
MOSFET N-CH 25V 39A TDSON-8
INFINEON, BSC050NE2LS
14
2
Q2, Q4
MOSFET N-CH 25V 38A TDSON-8
INFINEON, BSC010NE2LSI
15
5
R4, R14, R20, R31, R74
RES, CHIP, 0Ω , 0603
NIC, NRC06ZOTRF
16
2
R8, R26
RES, 3.32k, 1/10W, 1%, 0603
NIC, NRC06F3321TRF
17
2
R9, R10
RES, 10Ω, 1/10W, 1%, 0603
NIC, NRC06F10R0TRF
18
2
R12, R28
RES, 665Ω, 1/10W, 1%, 0603
NIC, NRC06F6650TRF
19
1
R15
RES, 2.2Ω, 1/10W, 1%, 0603
NIC, NRC06F2R20TRF
20
1
R16
RES, 20k, 1/10W, 1%, 0603
NIC, NRC06F2002TRF
21
3
R17, R37, R78
RES, 10k, 1/10W, 1%, 0603
NIC, NRC06F1002TRF
22
1
R36
RES, 30.1k, 1/10W, 1%, 0603
VISHAY, CRCW060330K1FKEA
23
1
R27
RES, 88.7k, 1/10W, 1%, 0603
VISHAY, CRCW060388K7FKEA
24
1
U1
IC, LTC3877EUK#PBF, QFN 7mm x 7mm
LINEAR TECH., LTC3877EUK#PBF
25
4
CIN5–CIN8
CAP, 22µF, X5R, 16V, 10%, 1210
MURATA., GRM32ER61C226KE20L
26
1
C21
CAP, 47PF, C0G , 50V, 5%, 0603
MURATA., GRM1885C1H470JA01D
27
2
C23, C27
CAP, 0.22µF, X7R, 10V, 10%, 0603
AVX., 0603ZC224KAT2A
28
1
C25
CAP, 4.7µF, X5R, 16V, 10%, 0805
AVX , 0805YD475KAT2A
29
3
C22, C24, C28
CAP, 0.1µF, X7R, 16V, 10%, 0603
TDK, C0603X7R1C104K
30
6
COUT13–COUT15, COUT18–COUT20
CAP, POSCAP, 330µF, 2.5V, 7343
PANASONIC, EEFSX0E331ER
31
4
COUT11, COUT12, COUT16, COUT17
CAP, 220µF, X5R, 4V, 10% 1206
MURATA., GRM31CR60G227ME11
32
2
Q5, Q7
MOSFET N-CH 25V 39A TDSON-8
INFINEON, BSC050NE2LS
33
2
Q6, Q8
MOSFET N-CH 25V 38A TDSON-8
INFINEON, BSC010NE2LSI
34
1
Q23
MOSFET N-CH 60V 300MA SOT-23
VISHAY, 2N7002K-T1-E3
35
2
L3, L4
INDUCTOR, 0.25µH
WURTH ELEKTRONIK., 744301025
36
2
D3, D4
DIODE, SCHOTTKY, SOD-323
CENTRAL SEMI., CMDSH-3TR
37
14
R39, R44, R45, R47, R49, R54, R55, R56,
R58, R61, R62, R66–R68
RES, CHIP, 0, 1%, 0603
NIC, NRC06ZOTRF
38
1
R18
RES, 4.02k, 1/10W, 1%, 0603
VISHAY, CRCW06034K02FKEA
39
1
R41
RES, 10k, 1/10W, 1%, 0603
VISHAY, CRCW060310K0FKEA
40
1
R82
RES, 4.22k, 1/10W, 1%, 0603
VISHAY, CRCW06034K22FKEA
10
dc2229af
DEMO MANUAL DC2229A
Parts List
ITEM
QTY
41
4
DC2155A-B
REFERENCE
PART DESCRIPTION
MANUFACTURER/PART NUMBER
R59, R60, R63, R64
RES, 0, 1%, 1225
TEPRO, RN5326
42
1
R50
RES, 78.7k, 1/10W, 1%, 0603
NIC, NRC06F7872TRF
43
2
R43, R53
RES, 665Ω, 1/10W, 1%, 0603
NIC, NRC06F6650TRF
44
1
R46
RES, 2.2Ω, 1/10W, 1%, 0603
NIC, NRC06F2R20TRF
45
1
R76
RES, 30.1k, 1/10W, 1%, 0603
VISHAY, CRCW060330K1FKEA
46
1
U1
IC, STEP-DOWN CONVERTER
LINEAR TECH, LTC3877EUK#PBF
47
1
U2
IC, STEP-DOWN CONTROLLER, SLAVE
LINEAR TECH., LTC3874IUFD#PBF
MOSFET N-CH 30V 80A D2PAK
VISHAY, SUM60N02-3M9P-E3
Dynamic Load Circuits
1
2
Q21, Q22
2
2
R70, R72
RES, 10k, 1/10W, 1%, 0603
NIC, NRC06F1002TRF
3
2
R71, R73
RES, 0.002Ω, 1%, 1/2W, 2010
VISHAY, WSL20102L000FEA
Additional Demo Board Circuit Components
1
0
C12, C13, C15
CAP, OPTIONAL
2
0
C20, C29, C32, C7, C16, C34
CAP, OPTIONAL
3
1
C26
CAP, 47nF, X5R, 25V, 10%, 0603
4
0
C33
CAP, 1206, OPTIONAL
5
0
C7, C16, C34
CAP, 0603, OPTIONAL
6
0
CIN11
CAP, OS-CON, SVP-F8
7
0
CIN12–CIN19
CAP, 1210, OPTIONAL
8
0
COUT21–COUT44
POSCAP, 7343, OPTIONAL
9
0
Q17–Q20
MOSFET, DUAL N-CHANNEL OPTIONAL
10
0
Q9–Q16
MOSFET, N-CHANNEL, POWERPAK OPTIONAL
RES, CHIP, 0Ω , 0603
AVX., 06033D473KAT2A
INFINEON, BSG0811ND
11
2
R13, R22
12
0
R1–R3, R5, R6, R7, R11, R19, R21, R23, R24, RES, OPTIONAL
R29, R30, R32, R40, R42, R48, R51, R52,
R57, R65, R69, R79, R80, R81, R75, R77,
RN1, RN2
NIC, NRC06ZOTRF
13
1
R25
RES, 10k, 1/10W, 1%, 0603
NIC, NRC06F1002TRF
14
2
R33, R34
RES, 10Ω, 1/10W, 1%, 0603
NIC, NRC06F10R0TRF
15
2
R35, R38
RES, 100k, 1/10W, 1%, 0603
NIC, NRC06F1003TRF
16
1
U3
IC, LT6703IDC-3#PBF
LINEAR TECH., LT6703IDC-3#PBF
Hardware: For Demo Board Only
1
26
E1–E26
TESTPOINT, TURRET, 0.094"
MILL-MAX, 2503-2-00-80-00-00-07-0
2
6
J1–J8
RING, LUG #10
KEYSTONE, 8205, #10
3
6
J1–J8
STUD, TESTPIN
PEM, KFH-032-10
4
6
J1–J8
WASHER, TIN PLATED BRASS
ANY #10
5
12
J1–J8 X (2)
NUT, BRASS 10-32
ANY #10-32
6
2
J9, J10
CONN, BNC 5PINS
CONNEX, 112404
7
8
JP1–JP7, JP10
HEADER, 3-PIN 0.079 SINGLE ROW
SULLINS, NRPN031PAEN-RC
8
2
JP8, JP9
HEADER, 4-PIN, 2mm SINGLE ROW
SULLINS, NRPN041PAEN-RC
dc2229af
11
A
B
C
JP8
E7
2
3
SGND
CLKOUTA
60 DEG
90 DEG
120 DEG
E12
E11
3
2
JP9 INTVCCA
PHASMD
PLLIN
BURST
FCM
PULSE SKIP
R25
10K
INTVCCA
0
R22
R11
OPT
5
CLKOUTA
PHASMD
PGOOD2
PGOOD1
VFB2-
VFB2+
E13
R38
100K
INTVCCA
E10
R24
10K
R35
100K
INTVCCA
OPT
C16
15K
R7
OPT
C2
C3
0.22uF 0.22uF
R6
OPT
PGOOD2
PGOOD1
C19
VID1
VID1
2
VID0
4
E14
EXTVCCA
0.22uF 0.22uF
R29
R30
OPT
OPT
EXTVCCA
VFB2-
VFB2+
TK/SS2
ITH2
ITH1
C18
DIFFOUT
VOSNS1-
VOSNS1+
TK/SS1
VFB1
H
L
ITEMP1
VID1
VID2
VID2
H
L
VID3
2
VID3
VID4
H
L
VID3
2
GND
R37
10K
R36
30.1K
INTVCCA
E26
VID4
2
C20
OPT
EXTVCCA
0
R20
C11
4.7uF
16V
0805
INTVCCA
0
R14
H
L
4
Q2
4
VID_EN
BG2
4
Q4
4
TG2
C14
0.1uF
D2
CMDSH-3
D1
CMDSH-3
C6
0.1uF
VID5
2
JP6
H
L
2
JP7
3
VID_EN
OPT
R15
4
BSC010NE2LSI
4
Q3
BSC050NE2LS
R75
C8
0.1uF
4
BSC010NE2LSI
4
Q1
BSC050NE2LS
1. ALL RESISTORS ARE 0603.
2. ALL CAPACITORS ARE 0603.
3. INSTALL SHUNTS ON JUMPERS AS SHOWN.
23
24
25
26
27
28
29
30
31
32
33
BG1
TG1
VID5
3
NOTES: UNLESS OTHERWISE SPECIFIED
SW2
TG2
BOOST2
BG2
EXTVCC
INTVCC
VIN
BG1
BOOST1
TG1
SW1
CLKOUTA
RUN
PGOOD2
R27
PGOOD1
88.7K
PHASMD
MODE_PLLIN
FSW = 400kHz
H
L
JP5
U1
LTC3877EUK
VID4
INTVCCA
CHL_SEL
VID_EN
VID5
VID2
JP4
SNSA2+
12
SNSA1+
R32
OPT
11
8
7
10
C15
0.1uF
ITH2
ITH1
6
5
R21
R17
10K
4
3
2
1
R5
OPT
9
20K
VFB1
C7 OPT
R2
OPT
C9 100pF
R18
C10
3.3nF
4.75K
C12 47pF
R19
C13
2.2nF
10.7K
R16
C4
0.1uF
R3
OPT
MODE_PLLIN
R23
OPT
TKSS2
TKSS1
RN1
OPT
R13 0
E6
E4
MODE
TK/SS2
TK/SS1
RN2
OPT
R1
OPT
VID0
2
JP3
SNS213
ITEMP1
H
L
JP2
14
D
VID0
JP1
45
GND
SNSD2+
2
1
1
3
44
SNS1-
1
3
VID0
ILIM
15
41
VID1
RUN
16
40
VID2
FREQ
17
2
1
4
1
1
4
43
SNSDC1+
42
ITEMP1
1
3
18
39
VID3
MODE_PLLIN
38
VID4
PHASMD
19
37
20
35
VID5
PGOOD1
36
1
3
34
VID_EN
PGOOD2
21
1
3
1
3
1
3
4
1
2
3
CHL_SEL
CLKOUT
22
5
1
2
3
5
1
2
3
5
1
2
3
5
5
R26
3.32K
CIN2
22uF
16V
1210
0.25uH
744301025
L2
CIN4
22uF
16V
1210
-B
-A
R28
665
CIN3
22uF
16V
1210
COUT7
220uF
4V
1206
APPROVALS
COUT6
220uF
4V
1206
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
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.
HZ
VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL
APP ENG. M. SHRIVER
APPLICATION. COMPONENT SUBSTITUTION AND PRINTED
CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT
PERFORMANCE OR RELIABILITY. CONTACT LINEAR
TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
2
+
COUT3
330uF
2.5V
+
COUT5
330uF
2.5V
R9
10
PRODUCTION
VOUT2
COUT4
330uF
2.5V
1
VIN
COUT8
330uF
2.5V
+
+
VIN+
GND
VO1_SNS-
VO1_SNS+
VIN-
R34
10
E9
E8
J6
C17
10uF J5
6.3V
0805
VO2_SNS-
VO2_SNS+
VOUT2-
1.5V / 30A
VOUT2+
NOT STUFFED
VOUT_SLAVE
VOUT1+
C5 J3
10uF
0.6V - 1.23V / 30A
6.3V
0805
VOUT1J4
E5
E3
E2
J2
IC NO.
DATE: JULY 20, 2015
N/A
SIZE
1
DC2229A-A
SHEET 1
RE V .
OF 3
2
HIGH CURRENT STEP-DOWN CONVERTER WITH VID
PROGRAMMING AND LOW DCR INDUCTORS
LTC3877EUK
1630 McCarthy Blvd.
Milpitas, CA 95035
Phone: (408)432-1900 www.linear.com
Fax: (408)434-0507
LTC Confidential-For Customer Use Only
R33
10
COUT10
330uF
2.5V
TECHNOLOGY
COUT9
330uF
2.5V
TITLE: SCHEMATIC
+
VOUT2
DATE
3-5-15
VIN
J1 6V - 14V
CIN10
+180uF
16V
E1
MIKE S.
APPROVED
CIN9
+180uF
16V
R10
10
DESCRIPTION
REVISION HISTORY
1.5V/30A
+
VOUT1
2
REV
0.6V-1.23V/120A 4 PHASE
VOUT1
COUT2
220uF
4V
1206
__
ECO
0.6V-1.23V/30A
COUT1
220uF
4V
1206
R4
0
R31
0
R12
665
0.25uH
744301025
L1
R8
3.32K
CIN1
22uF
16V
1210
SW1
C1
0.1uF
2
CUSTOMER NOTICE
Q12
OPT
SW2
Q11
OPT
2.2
Q10
OPT
Q9
OPT
1
2
3
5
1
2
3
5
1
2
3
5
12
1
2
3
5
A
B
C
D
DEMO MANUAL DC2229A
Schematic Diagram
dc2229af
A
B
C
D
FAULT_SLAVE
E25
5
3
E15
EXTVCCB
R48
OPT
OPT
Q23
OPT
EXTVCCB
C26
OPT
R47
RUN_SLAVE
2
PGOOD1
TKSS1
1
C27
OPT
C23
OPT
C21
OPT
ITH_SLAVE
8
7
6
5
4
3
2
1
R42
OPT
R39
OPT
INTVCCB
MODE1
ISENSE1+
ISENSE1-
RUN1
RUN0
ISENSE0-
ISENSE0+
MODE0
R41
OPT
INTVCCB
4
R50
OPT
4
R54
OPT
R52
INTVCCB
OPT
CLKOUTA
GND
SW1
BOOST1
BG1
EXTVCC
INTVCC
VIN
BG0
BOOST0
29
15
16
17
18
19
20
21
R56
OPT
R51
OPT
INTVCCB
EXTVCCB
BG4
C29
OPT
4
Q8
4
TG4
D4
OPT
D3
OPT
C28
OPT
4
4
Q6
BG3
TG3
C22
OPT
EXTVCCB
OPT
R49
C25
OPT
0805
INTVCCB
R45 OPT
U2
LTC3874IUFD#PBF
OPTIONAL
22
FAULT_SLAVE
LOWDCR
FREQ
10
5
FAULT0B
ILIM
11
27
12
26
FAULT1B
SYNC
25
PHASMD
13
28
ITH0
ITH1
9
24
TG0
23
SW0
TG1
14
3
5
Q5
OPT
OPT
1
2
3
5
Q7
OPT
R77
C24
OPT
1
2
3
5
OPT
1
2
3
5
3
1
2
3
R46
R66
OPT
VFB2-
4
4
OPT
4
4
5
L4
R57
OPT
R53
OPT
OPT
R55
OPT
R44
OPT
R69 OPT
RUN_SLAVE
R62 OPT
COUT17
OPT
1206
COUT12
OPT
1206
+
+
+
COUT18
OPT
7343
APPROVALS
2
SCALE = NONE
+
COUT19
OPT
7343
OPT
OPT
VOUT_SLAVE-
VOUT_SLAVE+
IC NO.
DATE: JULY 20, 2015
N/A
SIZE
1
DC2229A-A
SHEET 2
REV.
OF 3
2
HIGH CURRENT STEP-DOWN CONVERTER WITH VID
PROGRAMMING AND LOW DCR INDUCTORS
LTC3877EUK
1630 McCarthy Blvd.
Milpitas, CA 95035
Phone: (408)432-1900 www.linear.com
Fax: (408)434-0507
LTC Confidential-For Customer Use Only
R64
OPT
1225
TECHNOLOGY
R63
OPT
1225
TITLE: SCHEMATIC
J8
J7
1
VOUT2
VOUT_SLAVE
R60 OPT
1225
COUT20
OPT
7343
COUT15
OPT
7343
R59 OPT
1225
+
COUT14
OPT
7343
VOUT1
+
COUT13
OPT
7343
VOUT_SLAVE
CAP-SVP-F8
CIN11
+OPT
VIN
ITH_SLAVE
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
CUSTOMER NOTICE
RUN
R67 OPT
VFB2+
R61 OPT
VFB1
ITH1
2
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.
HZ
VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL
APP ENG. M. SHRIVER
APPLICATION. COMPONENT SUBSTITUTION AND PRINTED
CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT
PERFORMANCE OR RELIABILITY. CONTACT LINEAR
TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
TKSS2
R65
0
R68 OPT
TKSS1
CHL_SEL
R58
OPT
INTVCCA
ITH2
COUT16
OPT
1206
COUT11
OPT
1206
JUMPERS TO TIE PHASES TOGETHER
Q16
OPT
CIN7
OPT
1210
CIN6
OPT
1210
CIN8
OPT
1210
OPT
L3
R40
OPT
R43
OPT
CIN5
OPT
1210
SW3
VIN
SW4
Q15
OPT
OPT
Q14
OPT
Q13
OPT
1
2
3
5
1
2
3
5
1
2
3
5
1
2
3
FAULT_SLAVE
A
B
C
D
DEMO MANUAL DC2229A
Schematic Diagram
13
dc2229af
A
B
C
D
+
+
COUT27
OPT
7343
COUT21
OPT
7343
+
COUT39
OPT
7343
+
COUT40
OPT
7343
COUT34
OPT
7343
COUT28
OPT
7343
+
+
+
+
COUT41
OPT
7343
COUT35
OPT
7343
COUT29
OPT
7343
COUT23
OPT
7343
+
+
+
+
COUT24
OPT
7343
COUT30
OPT
7343
COUT36
OPT
7343
COUT42
OPT
7343
+
+
+
+
COUT43
OPT
7343
COUT37
OPT
7343
COUT31
OPT
7343
COUT25
OPT
7343
CIN16
OPT
1210
CIN12
OPT
1210
VIN
5
TG3
SW3
CIN17
OPT
1210
TG1
SW1
CIN13
OPT
1210
1
2
3
4
1
2
3
4
8
SW4
4
TG4
1
2
3
7
BG3
CIN19
OPT
1210
1
6
CIN18
OPT
1210
TG2
4
SW3
BG1
5
Q19
BSG0811ND
OPT
8
2
3
7
SW2
CIN15
OPT
1210
6
CIN14
OPT
1210
COUT44
OPT
7343
COUT38
OPT
7343
COUT32
OPT
7343
4
SW1
+
+
+
+
COUT26
OPT
7343
4
5
Q17
BSG0811ND
OPT
OPTIONAL DUAL CHANNEL MOSFETS
+
COUT33
OPT
7343
+
+
+
COUT22
OPT
7343
OPTIONAL COUT
VOUT_SLAVE
VOUT2
VOUT1
9
10
9
10
9
10
9
10
8
7
6
5
Q20
BSG0811ND
OPT
8
7
6
5
Q18
BSG0811ND
OPT
VOUT1
E18
E16
R70
10k
1%
VOUT1
ISTEP1+
R71 E17 LOAD STEP
0.002
2mV / Amp
1%
2010
ISTEP1E19
J9
BG4
SW4
BG2
SW2
GND
PULSE GEN2
E22
E20
3
R72
10k
1%
Q22
SUM60N02-3m9P
TO-263AB
E23
E21
C33
OPT
1206
R79
OPT
0805
VIN
VOUT2
R81
OPT
R80
OPT
RUN
2
RUN
R78
10.0k
R82
0
1
APPROVALS
2
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
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.
HZ
VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL
APP ENG. M. SHRIVER
APPLICATION. COMPONENT SUBSTITUTION AND PRINTED
CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT
PERFORMANCE OR RELIABILITY. CONTACT LINEAR
TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
R74
0
RUN
RUN_SLAVE
LTC3877EUK
TECHNOLOGY
REV.
1630 McCarthy Blvd.
Milpitas, CA 95035
Phone: (408)432-1900 www.linear.com
Fax: (408)434-0507
LTC Confidential-For Customer Use Only
IC NO.
DATE: JULY 20, 2015
N/A
SIZE
1
DC2229A-A
SHEET 3
OF 3
2
HIGH CURRENT STEP-DOWN CONVERTER WITH VID
PROGRAMMING AND LOW DCR INDUCTORS
TITLE: SCHEMATIC
Use Tepro RN5326 for 0 Ohm, 1225 resistor
CIN1-4: Murata GRM32ER61C226KE20L (22uF, 16V, X5R, 1210)
CIN9,10: Sanyo 16SVP180MX (180uF, 16V, 30mOhm, 3.0 A RMS)
COUT3-5,8-10: Panasonic EEFSX0E331ER (330uF, 9mOhms, 2.5V, 7343)
COUT1,2,6,7: Murata GRM31CR60G227M (220uF, 4V, X5R, 1206)
L1,2: Wurth 744301025
(250nH, DCR=0.32mOhms +/- 7%, Isat = 65A typical,
footprint = 11.3mm X 11mm, H = 8.9mm)
Notes to PCB designer:
2
CUSTOMER NOTICE
OPT
4
U3 LT6703IDC-3
C32
OPT
R76
34.8k
VIN
OUT
VS
+INA GND
C34
OPT
3
2
1
E24
ISTEP2-
ISTEP2+
LOAD STEP
2mV / Amp
J10
JP10
ON
RUN
OFF
R73
0.002
1%
2010
VOUT2
DYNAMIC LOAD CIRCUIT FOR VOUT2
GND
PULSE GEN1
Q21
SUM60N02-3m9P
TO-263AB
DYNAMIC LOAD CIRCUIT FOR VOUT1
3
1
14
3
5
A
B
C
D
DEMO MANUAL DC2229A
Schematic Diagram
dc2229af
A
B
C
E7
2
3
SGND
CLKOUTA
60 DEG
90 DEG
120 DEG
E12
E11
3
2
JP9 INTVCCA
PHASMD
PLLIN
BURST
FCM
PULSE SKIP
MODE
R25
10K
INTVCCA
0
R22
R11
OPT
5
CLKOUTA
PHASMD
20K
PGOOD2
PGOOD1
VFB2-
VFB2+
C15
OPT
E13
R17
10K
R24
OPT
R38
100K
R7
OPT
VID0
2
C2
C3
PGOOD2
PGOOD1
C19
VID1
VID1
2
VID0
4
E14
EXTVCCA
0.22uF 0.22uF
R29
R30
OPT
OPT
EXTVCCA
VFB2-
VFB2+
TK/SS2
ITH2
ITH1
C18
DIFFOUT
VOSNS1-
VOSNS1+
TK/SS1
VFB1
H
L
ITEMP1
VID1
0.22uF 0.22uF
R6
OPT
SNSA1+
R32
OPT
11
10
9
8
7
6
5
4
3
2
1
R5
OPT
ITH2
ITH1
R35
100K
INTVCCA
E10
INTVCCA
OPT
C16
OPT
R21
C13
OPT
C10
3.3nF
VFB1
C7 OPT
R2
OPT
C9 100pF
R18
4.02K
C12 OPT
R19
OPT
R16
C4
0.1uF
R3
OPT
MODE_PLLIN
R23
OPT
TKSS2
TKSS1
RN1
OPT
R13 0
E6
E4
JP8
TK/SS2
TK/SS1
RN2
OPT
R1
OPT
ITEMP1
H
L
JP2
VID2
VID2
H
L
VID3
VID3
VID4
H
L
VID3
2
JP4
GND
R37
10K
R36
30.1K
INTVCCA
E26
VID4
2
C20
OPT
EXTVCCA
0
R20
C11
4.7uF
16V
0805
INTVCCA
0
R14
H
L
4
Q2
4
VID_EN
BG2
4
Q4
4
TG2
C14
0.1uF
D2
CMDSH-3
D1
CMDSH-3
C6
0.1uF
VID5
2
JP6
H
L
R75
2
JP7
3
VID_EN
R15
4
BSC010NE2LSI
4
Q3
BSC050NE2LS
OPT
C8
0.1uF
4
BSC010NE2LSI
4
Q1
BSC050NE2LS
1. ALL RESISTORS ARE 0603.
2. ALL CAPACITORS ARE 0603.
3. INSTALL SHUNTS ON JUMPERS AS SHOWN.
23
24
25
26
27
28
29
30
31
32
33
BG1
TG1
VID5
3
NOTES: UNLESS OTHERWISE SPECIFIED
SW2
TG2
BOOST2
BG2
EXTVCC
INTVCC
VIN
BG1
BOOST1
TG1
SW1
CLKOUTA
RUN R27
PGOOD2
PGOOD1
88.7K
PHASMD
MODE_PLLIN
FSW = 400kHz
H
L
JP5
U1
LTC3877EUK
VID4
INTVCCA
CHL_SEL
VID_EN
VID5
VID2
2
JP3
SNSA2+
12
D
VID0
JP1
45
GND
SNS213
2
1
1
3
44
SNS1-
1
3
SNSD2+
14
41
VID0
ILIM
15
2
1
4
1
1
4
43
SNSDC1+
42
ITEMP1
VID1
RUN
16
40
1
3
VID2
FREQ
17
39
VID3
MODE_PLLIN
18
38
VID4
PHASMD
19
37
20
35
VID5
PGOOD1
36
1
3
34
VID_EN
PGOOD2
21
1
3
1
3
1
3
4
1
2
3
CHL_SEL
CLKOUT
22
5
1
2
3
5
1
2
3
5
1
2
3
5
5
R26
3.32K
L2
CIN4
22uF
16V
1210
0.25uH
744301025
R28
665
CIN3
22uF
16V
1210
-B
-A
CIN2
22uF
16V
1210
COUT2
220uF
4V
1206
R31
0
COUT7
220uF
4V
1206
APPROVALS
COUT6
220uF
4V
1206
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
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.
HZ
VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL
APP ENG. M. SHRIVER
APPLICATION. COMPONENT SUBSTITUTION AND PRINTED
CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT
PERFORMANCE OR RELIABILITY. CONTACT LINEAR
TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
2
+
COUT3
330uF
2.5V
__
ECO
COUT4
330uF
2.5V
1
COUT8
330uF
2.5V
+
+
VO1_SNS-
R34
10
E9
E8
J6
C17
10uF J5
6.3V
0805
VO2_SNS-
VO2_SNS+
VOUT2-
VOUT2+
IC NO.
DATE: JULY 20, 2015
N/A
SIZE
1
DC2229A-B
SHEET 1
2
REV.
OF 3
HIGH CURRENT STEP-DOWN CONVERTER WITH VID
PROGRAMMING AND LOW DCR INDUCTORS
LTC3877EUK
1630 McCarthy Blvd.
Milpitas, CA 95035
Phone: (408)432-1900 www.linear.com
Fax: (408)434-0507
LTC Confidential-For Customer Use Only
R33
10
GND
VINVO1_SNS+
NOT STUFFED
COUT10
330uF
2.5V
TECHNOLOGY
COUT9
330uF
2.5V
TITLE: SCHEMATIC
+
VOUT2
VIN+
D
A
B
VOUT1+
C5 J3
10uF
0.6V - 1.23V / 120A C
6.3V
0805
VOUT1J4
E5
E2
J2
CIN10
+180uF
16V
E3
DATE
3-5-15
VIN
J1 6V - 14V
E1
VOUT_SLAVE
COUT5
330uF
2.5V
1.5V/30A
+
R9
10
VIN
MIKE S.
APPROVED
CIN9
+180uF
16V
R10
10
DESCRIPTION
REVISION HISTORY
PRODUCTION
VOUT2
+
VOUT1
2
REV
0.6V-1.23V/120A 4 PHASE
VOUT1
COUT1
220uF
4V
1206
R4
0
0.6V-1.23V/30A
R12
665
0.25uH
744301025
L1
R8
3.32K
CIN1
22uF
16V
1210
SW1
C1
0.1uF
2
CUSTOMER NOTICE
Q12
OPT
SW2
Q11
OPT
2.2
Q10
OPT
Q9
OPT
1
2
3
5
1
2
3
5
1
2
3
5
1
2
3
5
DEMO MANUAL DC2229A
Schematic Diagram
15
dc2229af
A
B
C
D
FAULT_SLAVE
E25
0
5
EXTVCCB
C26
47nF
R47
RUN_SLAVE
Q23
2N7002
2
PGOOD1
3
E15
EXTVCCB
R48
OPT
TKSS1
C27
0.22uF
C23
0.22uF
C21
47pF
ITH_SLAVE
8
7
6
5
4
3
2
1
R42
OPT
R39
0
INTVCCB
MODE1
ISENSE1+
ISENSE1-
RUN1
RUN0
ISENSE0-
ISENSE0+
MODE0
R41
10K
INTVCCB
4
R54
0
R52
OPT
CLKOUTA
R50
INTVCCB
78.7K
GND
SW1
BOOST1
BG1
EXTVCC
INTVCC
VIN
BG0
BOOST0
R56
0
R51
OPT
C29
OPT
EXTVCCB
BG4
4
Q8
4
INTVCCB
TG4
C28
0.1uF
D4
CMDSH-3
R77
D3
CMDSH-3
29
R49 0
C25
4.7uF
0805
INTVCCB
EXTVCCB
C22
0.1uF
4
4
BG3
TG3
15
16
17
18
19
20
21
R45 0
U2
LTC3874IUFD#PBF
OPTIONAL
22
FAULT_SLAVE
LOWDCR
FREQ
10
1
4
FAULT0B
ILIM
11
27
12
26
FAULT1B
SYNC
25
PHASMD
28
ITH0
ITH1
9
24
TG0
23
SW0
TG1
13
5
3
BSC010NE2LSI
Q6
3
4
4
Q5
BSC050NE2LSI
R46
R66
0
VFB2-
4
BSC010NE2LSI
4
Q7
BSC050NE2LSI
OPT
C24
0.1uF
1
2
3
14
5
1
2
3
5
1
2
3
5
1
2
3
5
5
R53
665
OPT
R57
0.25uH
744301025
L4
CIN8
22uF
1210
16V
CIN6
22uF
1210
16V
0.25uF
744301025
L3
R55
0
R44
0
R68 0
TKSS1
CHL_SEL
R61 0
R62 0
R69 OPT
RUN_SLAVE
VFB2+
COUT17
220uF
1206
4V
COUT12
220uF
1206
+
+
COUT18
330uF
7343
2.5V
COUT13
330uF
7343
2.5V
2
+
+
J8
J7
1
GND
VOUT
SCALE = NONE
APPROVALS
LTC3877EUK
TECHNOLOGY
IC NO.
DATE: JULY 20, 2015
N/A
SIZE
1
DC2229A-B
SHEET 2
2
REV.
OF 3
HIGH CURRENT STEP-DOWN CONVERTER WITH VID
PROGRAMMING AND LOW DCR INDUCTORS
TITLE: SCHEMATIC
1630 McCarthy Blvd.
Milpitas, CA 95035
Phone: (408)432-1900 www.linear.com
Fax: (408)434-0507
LTC Confidential-For Customer Use Only
RUN AND RUN _SLAVE DRIVEN WITH DIVIDER ON SHEET3.
R64
0
1225
VOUT2
VOUT_SLAVE
R60 0
1225
COUT20
330uF
7343
2.5V
COUT15
330uF
7343
2.5V
R63
0
1225
R59 0
1225
COUT19
330uF
7343
2.5V
COUT14
330uF
7343
2.5V
VOUT1
+
+
VOUT_SLAVE
CAP-SVP-F8
CIN11
+OPT
VIN
ITH_SLAVE
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
CUSTOMER NOTICE
RUN
R67 0
VFB1
ITH1
2
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.
HZ
VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL
APP ENG. M. SHRIVER
APPLICATION. COMPONENT SUBSTITUTION AND PRINTED
CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT
PERFORMANCE OR RELIABILITY. CONTACT LINEAR
TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
TKSS2
R65
OPT
R58
0
INTVCCA
ITH2
COUT16
220uF
1206
4V
COUT11
220uF
1206
JUMPERS TO TIE PHASES TOGETHER
Q16
OPT
CIN7
22uF
1210
16V
R40
OPT
R43
665
CIN5
22uF
1210
16V
SW3
VIN
SW4
Q15
OPT
2.2
Q14
OPT
Q13
OPT
1
2
3
5
1
2
3
5
1
2
3
5
16
1
2
3
FAULT_SLAVE
A
B
C
D
DEMO MANUAL DC2229A
Schematic Diagram
dc2229af
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.
A
B
C
D
+
+
COUT27
OPT
7343
COUT21
OPT
7343
+
COUT39
OPT
7343
+
COUT40
OPT
7343
COUT34
OPT
7343
COUT28
OPT
7343
COUT22
OPT
7343
+
+
+
+
COUT41
OPT
7343
COUT35
OPT
7343
COUT29
OPT
7343
COUT23
OPT
7343
+
+
+
+
COUT24
OPT
7343
COUT30
OPT
7343
COUT36
OPT
7343
COUT42
OPT
7343
+
+
+
+
COUT43
OPT
7343
COUT37
OPT
7343
COUT31
OPT
7343
COUT25
OPT
7343
CIN16
OPT
1210
CIN12
OPT
1210
VIN
5
TG3
SW3
CIN17
OPT
1210
TG1
SW1
CIN13
OPT
1210
1
2
3
4
1
2
3
4
8
BG3
4
TG4
1
2
3
7
SW4
CIN19
OPT
1210
1
2
6
CIN18
OPT
1210
TG2
4
SW3
BG1
5
Q19
BSG0811ND
OPT
8
7
3
SW2
CIN15
OPT
1210
6
CIN14
OPT
1210
COUT44
OPT
7343
COUT38
OPT
7343
COUT32
OPT
7343
COUT26
OPT
7343
4
SW1
+
+
+
+
4
5
Q17
BSG0811ND
OPT
OPTIONAL DUAL CHANNEL MOSFETS
+
COUT33
OPT
7343
+
+
+
OPTIONAL COUT
VOUT_SLAVE
VOUT2
VOUT1
9
10
9
10
9
10
9
10
8
7
6
5
Q20
BSG0811ND
OPT
8
7
6
5
Q18
BSG0811ND
OPT
VOUT1
E18
E16
R70
10k
1%
VOUT1
ISTEP1+
R71 E17 LOAD STEP
0.005
5mV / Amp
1%
2010
ISTEP1E19
J9
BG4
SW4
BG2
SW2
GND
PULSE GEN2
E22
E20
3
R72
10k
1%
R73
0.005
1%
2010
VOUT2
SUM60N02-3m9P
TO-263AB
Q22
C33
OPT
1206
R79
OPT
0805
VIN
R78
10.0k
R82
4.22k
APPROVALS
R74
0
RUN
2
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
CUSTOMER NOTICE
OPT
4
U3 LT6703IDC-3
C32
OPT
R76
30.1k
RUN_SLAVE
SCALE = NONE
LTC3877EUK
TECHNOLOGY
IC NO.
DATE: JULY 20, 2015
N/A
SIZE
1
DC2229A-B
SHEET 3
OF 3
2
RE V .
1630 McCarthy Blvd.
Milpitas, CA 95035
Phone: (408)432-1900 www.linear.com
Fax: (408)434-0507
LTC Confidential-For Customer Use Only
HIGH CURRENT STEP-DOWN CONVERTER WITH VID
PROGRAMMING AND LOW DCR INDUCTORS
TITLE: SCHEMATIC
Use Tepro RN5326 for 0 Ohm, 1225 resistor
CIN1-8: Murata GRM32ER61C226KE20L (22uF, 16V, X5R, 1210)
CIN9,10: Sanyo 16SVP180MX (180uF, 16V, 30mOhm, 3.0 A RMS)
COUT3-5,8-10,13-15,18-20: Panasonic EEFSX0E331ER (330uF, 9mOhms, 2.5V, 7343)
VIN
OUT
VS
+INA GND
C34
OPT
3
2
1
E24
1
COUT1,2,6,7,11,12,16,17: Murata GRM31CR60G227M (220uF, 4V, X5R, 1206)
L1- 4: Wurth 744301025
(250nH, DCR=0.32mOhms +/- 7%, Isat = 65A typical,
footprint = 11.3mm X 11mm, H = 8.9mm)
Notes to PCB designer:
2
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.
HZ
VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL
APP ENG. M. SHRIVER
APPLICATION. COMPONENT SUBSTITUTION AND PRINTED
CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT
PERFORMANCE OR RELIABILITY. CONTACT LINEAR
TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
R81
OPT
R80
OPT
RUN
2
RUN
ISTEP2-
ISTEP2+
LOAD STEP
5mV / Amp
JP10
ON
RUN
OFF
E23
E21
J10
VOUT2
DYNAMIC LOAD CIRCUIT FOR VOUT2
GND
PULSE GEN1
Q21
SUM60N02-3m9P
TO-263AB
DYNAMIC LOAD CIRCUIT FOR VOUT1
3
1
3
5
A
B
C
D
DEMO MANUAL DC2229A
Schematic Diagram
dc2229af
17
DEMO MANUAL DC2229A
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
18 Linear Technology Corporation
dc2229af
LT 0815 • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900
●
FAX: (408) 434-0507 ● www.linear.com
 LINEAR TECHNOLOGY CORPORATION 2015