DC1801A - Demo Manual

DEMO MANUAL DC1801A
LTC3838EUHF
High Efficiency Dual Output
Step-Down DC/DC Converter
DESCRIPTION
Demonstration circuit 1801A is a dual output 1.5V/20A and
1.2V/20A synchronous buck converter operating with a
switching frequency of 300kHz over an input voltage range
of 4.5V to 14V. The demo board comes in two versions.
The A version uses inductor DCR current sensing for high
efficiency. The B version uses 2mΩ sense resistor for accurate current sensing with a low DCR ferrite inductor. The
fixed on-time valley current mode topology of the LTC3838
allows for a fast load step response (see Figures 6 to 9).
The load step response can be tested with the onboard
load step circuit and a bench pulse generator.
The demo board uses a high density, two sided drop in
layout. The entire converter, excluding the bulk output and
input capacitors, fits within a compact 1.5” × 1.0” area
on the board. The package style for the LTC3838EUHF is
a 38-pin QFN with an exposed ground pad.
PERFORMANCE SUMMARY
PARAMETER
The main features of the board are listed below:
• MODE jumper to program either discontinuous mode
(DCM) or forced continuous mode (FCM) at light or no
load.
• EXTVCC pin.
• PLLIN pin to synchronize the converter to an external
clock.
• Remote sensing for VOUT1.
• Optional resistors to tie the two phases together.
• Each rail has its own RUN pin, PGOOD pin and
TRACK/SS pin.
Design files for this circuit board are available at
http://www.linear.com/demo
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.
(TA = 25°C)
CONDITIONS
Minimum Input Voltage
VALUE
4.5V
Maximum Input Voltage
14V
Output Voltage VOUT1
IOUT1 = 0A to 20A, VIN = 4.5V to 14V
Output Voltage VOUT2
IOUT2 = 0A to 20A, VIN = 4.5V to 14V
1.5V ± 2%
VOUT1 Maximum Output Current, IOUT1
VIN = 4.5V to 14V, VOUT1 = 1.2V
20A
VOUT2 Maximum Output Current, IOUT2
VIN = 4.5V to 14V, VOUT2 = 1.5V
20A
Nominal Switching Frequency
1.2V ± 2%
300kHz
VOUT1 = 1.2V, IOUT1 = 20A, VIN = 12V
91% Typical
See Figures 2 and 3
VOUT2 = 1.5V, IOUT2 = 20A, VIN = 12V
92% Typical
-B Efficiency (RSENSE Current Sense)
VOUT1 = 1.2V, IOUT1 = 20A, VIN = 12V
89.5% Typical
See Figures 4 and 5
VOUT2 = 1.5V, IOUT2 = 20A, VIN = 12V
91% Typical
-A Efficiency (DCR Current Sense)
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1
DEMO MANUAL DC1801A
QUICK START PROCEDURE
Demonstration circuit 1801A is easy to set up to evaluate the performance of the LTC3838EUHF. Please refer to
Figure 1 for proper measurement equipment setup and
follow the procedure below.
1) With power off, connect the input supply, load and
meters as shown in Figure 1. Preset the load to 0A
and VIN supply to be 0V. Place jumpers in the following
positions:
JP4
RUN1
ON
JP1
RUN2
ON
JP3
MODE
FCM
2) Adjust the input voltage to be between 4.5V to 14V.
VOUT1 should 1.2V ± 2%.
VOUT2 should 1.5V ± 2%.
3) Next, apply 20A load and recheck VOUT.
4) Once the DC regulation is confirmed, observe the output
voltage ripple, load step response, efficiency and other
parameters.
Note 1. Use the BNC connectors labeled VOUT1 or VOUT2
to measure the output voltage ripple.
tor the voltage across COUT1 and COUT5 respectively.
Heavy load currents applied across these turrets may
damage the converter.
LOAD STEP TRANSIENT TESTING
Demonstration circuit 1801A provides a simple load step
circuit consisting of a MOSFET and sense resistor for each
rail. To apply a load step, follow the steps below.
1) Preset the amplitude of a pulse generator to 0.0V and
the duty cycle to 5% or less.
2) Connect the scope to the VOUT BNC connectors for
the rail under test with a coax cable. To monitor the
load step current, connect the scope probe across the
IOSTEP+/– turrets for that rail.
3) Connect the output of the pulse generator to the PULSE
GEN turret for the rail under test and connect the return
to one of the GND turrets.
4) With the converter running, slowly increase the amplitude of the pulse generator output to provide the desired
load step pulse height. The scaling for the LOAD STEP
signal is 10mV/Amp.
Note 2. Do not apply the load from the VO1_SNS+ turret
to the VO1_SNS– turret or from the VO2+ turret to the
VO2– turret. These turrets are only intended to moni-
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2
DEMO MANUAL DC1801A
QUICK START PROCEDURE
A single output/dual phase converter may be preferred for
high output current applications. The benefits of single
output/dual phase operation is lower ripple current through
the input and output capacitors, faster load step response
and simplified thermal design. To implement single output/
dual phase operation, make the following modifications:
• Tie VOUT1 to VOUT2 by tying together the exposed copper
pads on the VOUT shapes with pieces of heavy copper
foil.
• Remove the ITH compensation network, VFB divider
and TRACK/SS capacitor for phase-2.
• Tie VRNG1 to VRNG2 by stuffing 0Ω at R4.
• Tie RUN1 to RUN2 by stuffing 0Ω at R7.
• If the optional transient detect circuit is used, externally
tie the DTR1 pin to the DTR2 pin.
• Recompensate if necessary.
• Tie VFB2 to INTVCC by stuffing 0Ω at R1. This will
disable the error amp for phase-2 and internally tie the
two ITH signals together.
Figure 1. Proper Measurement Equipment Setup
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3
DEMO MANUAL DC1801A
QUICK START PROCEDURE
95
100
fSW = 300kHz
VIN = 12V
90
fSW = 300kHz
VIN = 12V
80
90
EFFICIENCY (%)
EFFICIENCY (%)
70
85
80
60
50
40
30
1.5V FCM
1.2V FCM
1.5V DCM
1.2V DCM
20
75
10
1.5V FCM
1.2V FCM
0
0.01
70
1
6
11
LOAD CURRENT (A)
21
16
0.1
1
LOAD CURRENT (A)
DC1801a F03
DC1801a F02
Figure 2. Efficiency Curves for the DC1801A-A
(DCRSENSE) in FCM
95
10
Figure 3. Efficiency Curves for the DC1801A-A
(DCRSENSE) in FCM and DCM.
100
fSW = 300kHz
VIN = 12V
90
90
fSW = 300kHz
VIN = 12V
80
EFFICIENCY (%)
EFFICIENCY (%)
70
85
80
60
50
40
30
75
1.5V FCM
1.2V FCM
1.5V DCM
1.2V DCM
20
10
1.5V FCM
1.2V FCM
70
1
6
11
LOAD CURRENT (A)
16
21
DC1801a F04
Figure 4. Efficiency Curves for the DC1801A-B
(RSENSE) in FCM
0
0.01
0.1
1
LOAD CURRENT (A)
10
DC1801a F05
Figure 5. Efficiency Curves for the DC1801A-B
(RSENSE) in FCM and DCM
dc1801af
4
DEMO MANUAL DC1801A
QUICK START PROCEDURE
15A
5A
LOAD STEP
1.2VO
50mV/DIV
106mV
20μs/DIV
DC1801a F06
Figure 6. Load Step Response of the 1.2V Rail on the DC1801A-A
(DCRSENSE) at VIN = 12V. COUT = 2× Sanyo 2R5TPE330M9 || 2× 100μF
X5R 6.3V 1206, L = 0.47μH, fSW = 300kHz
15A
LOAD STEP
5A
1.5VO
50mV/DIV
127mV
20μs/DIV
DC1801a F07
Figure 7. Load Step Response of the 1.5V Rail on the DC1801A-A
(DCRSENSE) at VIN = 12V. COUT = 2× Sanyo 2R5TPE330M9 || 2× 100μF
X5R 6.3V 1206, L = 0.47μH, fSW = 300kHz
dc1801af
5
DEMO MANUAL DC1801A
QUICK START PROCEDURE
15A
LOAD STEP
5A
1.2VO
50mV/DIV
112mV
20μs/DIV
DC1801a F08
Figure 8. Load Step Response of the 1.2V Rail on the DC1801A-B
(RSENSE) at VIN = 12V. COUT = 2× Sanyo 2R5TPE330M9 || 2× 100μF X5R
6.3V 1206, fSW = 300kHz, L = 0.44μH, fSW = 300kHz
15A
LOAD STEP
5A
1.5VO
50mV/DIV
119mV
20μs/DIV
DC1801a F09
Figure 9. Load Step Response of the 1.5V Rail on the DC1801A-B
(RSENSE) at VIN = 12V. COUT = 2× Sanyo 2R5TPE330M9 || 2× 100μF X5R
6.3V 1206, fSW = 300kHz, L = 0.44μH, fSW = 300kHz
dc1801af
6
DEMO MANUAL DC1801A
PARTS LIST
Demo Board 1801A-A
ITEM
QTY
REFERENCE
PART DESCRIPTION
MANUFACTURER/PART NUMBER
Required Circuit Components
1
1
CIN1
CAP, 180μF, 16V, SVP-F8
SANYO, 16SVP180MX
2
2
CIN3, CIN5
CAP, X5R, 22μF, 16V, 1210
MURATA, GRM312ER61C226KE20L
3
4
COUT1, COUT2, COUT5, COUT6
CAP, 330μF, 2.5V, SIZE 7343
SANYO, 2R5TPE330M9
4
4
COUT3, COUT4, COUT7, COUT8
CAP, X5R, 100μF, 6.3V, 1206
MURATA, GRM31CR60J107ME39L
5
2
C3, C16
CAP, X6R, 0.22μF, 25V, 0603
MURATA, GRM188R60E224KA88D
6
5
C4, C5, C10, C13, C14
CAP, X5R, 0.1μF, 16V, 0603
AVX, 0603YD104KAT2A
7
2
C6, C11
CAP, NPO, 47pF, 16V, 0603
AVX, 0603YA470JAT2A
8
2
C7, C12
CAP, X7R, 470pF, 16V, 0603
AVX, 0603YC471JAT2A
9
1
C8
CAP, X5R, 4.7μF, 16V, 0805
AVX, 0805YD475KAT2A
10
2
C9, C18
CAP, X5R, 1μF, 16V, 0603
AVX, 0603YD105KAT2A
11
2
D1, D2
DIODE, SCHOTTKY, SOD-323
CENTRAL SEMI, CMDSH-4E TR
12
2
L1, L2
IND, 0.47μH
WÜRTH, 744355047
13
2
Q1, Q3
MOSFET, OPTIMOS, PG-TDSON-8
INFINEON, BSC050NE2LS
14
2
Q2, Q4
MOSFET, OPTIMOS, PG-TDSON-8
INFINEON, BSC010NE2LS
15
2
Q9, Q10
MOSFET, N-CH, 30V, TO-252
VISHAY, SUD50N03-12P-E3
16
7
R8, R11, R16, R35, R39, R55, R57
RES, CHIP, 0, 0603
VISHAY, CRCW06030000Z0EA
17
2
R12, R38
RES, CHIP, 100k, 1%, 0603
VISHAY, CRCW0603100KFKEA
18
3
R13, R21, R31
RES, CHIP, 15k, 1%, 0603
VISHAY, CRCW060315K0FKEA
19
0
R14, R15, R24, R29, R41, R45 (OPT)
RES, CHIP, 0603
20
4
R17, R23, R40, R46
RES, CHIP, 10k, 1%, 0603
21
2
R18, R32
RES, CHIP, 2.15k 1%, 0603
VISHAY, CRCW06032K15FKEAEA
22
4
R20, R26, R30, R36
RES, CHIP, 0, 0603
VISHAY, CRCW06030000Z0EA
23
2
R25, R27
RES, CHIP, 2.2 1%, 0603
VISHAY, CRCW06032R20FKEA
24
1
R28
RES, CHIP, 133k, 1%, 0603
VISHAY, CRCW0603133KFKEA
25
2
R42, R43
RES, CHIP, 10, 1%, 0603
VISHAY, CRCW060310R0FKED
26
2
RS1, RS2
RES, CHIP, 0.000Ω, 2W, 2512
TEPRO, RN5326
27
1
U1
LTC3838EUHF, QFN, 38-LEAD
LINEAR TECHNOLOGY LTC3838EUHF
VISHAY, CRCW060310K0FKEA
Additional Demo Board Circuit Components
1
0
CIN2 (OPT)
CAP, OPT, SVP-F8
2
0
CIN4, CIN6, CIN7, CIN8 (OPT)
CAP, OPT, 1210
3
0
C1, C2, C15, C17 (OPT)
CAP, OPT, 0603
4
0
COUT13 TO COUT16 (OPT)
CAP, OPT, 7343
5
0
Q5 TO Q8 (OPT)
MOSFET, OPTIMOS, PG-TDSON-8
6
0
R1, R3, R4, R6, R7, R9, R10, R19, R34,
R37, R44, R49, R50, R47, R48, R56 (OPT)
RES, CHIP, 0603
7
2
R51, R52
RES, CHIP, 10k, 1%, 0603
VISHAY, CRCW060310K0FKEA
8
2
R53, R54
RES, CHIP, 0.01, 1/2W, 1%, 2010
VISHAY, WSL2010R0100FEA
dc1801af
7
DEMO MANUAL DC1801A
PARTS LIST
Demo Board 1801A-A
ITEM
QTY
REFERENCE
PART DESCRIPTION
MANUFACTURER/PART NUMBER
Hardware/Components (For Demo Board Only)
1
20
E1 TO E20
TESTPOINT, TURRET, 0.095"
MILL-MAX, 2501-2-00-80-00-00-07-0
2
2
JP1, JP4
2mm SINGLE ROW HEADER, 3-PIN
SAMTEC, TMM-103-02-L-S
3
2
JP2, JP3
2mm SINGLE ROW HEADER, 4-PIN
SAMTEC, TMM-104-02-L-S
4
4
XJP1 TO XJP4
SHUNT
SAMTEC, 2SN-BK-G
5
6
J1 TO J6
JACK, BANANA
KEYSTONE, 575-4
6
2
J7, J8
CONN, BNC, 5 PINS
CONNEX, 112404
7
2
J9, J10
2mm SINGLE ROW HEADER, 2-PIN
SAMTEC, TMM-102-02-L-S
8
4
MH1 TO MH4
STAND-OFF, NYLON 0.25"
KEYSTONE, 8831 (SNAP ON)
dc1801af
8
DEMO MANUAL DC1801A
PARTS LIST
Demo Board 1801A-B
ITEM
QTY
REFERENCE
PART DESCRIPTION
MANUFACTURER/PART NUMBER
Required Circuit Components
1
1
CIN1
CAP, 180μF, 16V, SVP-F8
SANYO, 16SVP180MX
2
2
CIN3, CIN5
CAP, X5R, 22μF, 16V, 1210
MURATA, GRM312ER61C226KE20L
3
4
COUT1, COUT2, COUT5, COUT6
CAP, 330μF, 2.5V, SIZE 7343
SANYO, 2R5TPE330M9
4
4
COUT3, COUT4, COUT7, COUT8
CAP, X5R, 100μF, 6.3V, 1206
MURATA, GRM31CR60J107ME39L
5
2
C3, C16
CAP, X7R, 1000pF, 16V, 0603
AVX, 0603YC102KAT2A
6
5
C4, C5, C10, C13, C14
CAP, X5R, 0.1μF, 16V, 0603
AVX, 0603YD104KAT2A
7
2
C6, C11
CAP, NPO, 47pF, 16V, 0603
AVX, 0603YA470JAT2A
8
2
C7, C12
CAP, X7R, 470pF, 16V, 0603
AVX, 0603YC471JAT2A
9
1
C8
CAP, X5R, 4.7μF, 16V, 0805
AVX, 0805YD475KAT2A
10
2
C9, C18
CAP, X5R, 1μF, 16V, 0603
AVX, 0603YD105KAT2A
11
2
D1, D2
DIODE, SCHOTTKY, SOD-323
CENTRAL SEMI, CMDSH-4E TR
12
2
L1, L2
IND, 0.44μH
COOPER, FP1308R3-R44-R
13
2
Q1, Q3
MOSFET, OPTIMOS, PG-TDSON-8
INFINEON, BSC050NE2LS
14
2
Q2, Q4
MOSFET, OPTIMOS, PG-TDSON-8
INFINEON, BSC010NE2LS
15
2
Q9, Q10
MOSFET, N-CH, 30V, TO-252
VISHAY, SUD50N03-12P-E3
16
7
R8, R11, R16, R35, R39, R55, R57
RES, CHIP, 0, 0603
VISHAY, CRCW06030000Z0EA
17
2
R12, R38
RES, CHIP, 100k, 1%, 0603
VISHAY, CRCW0603100KFKEA
18
3
R13, R21, R31
RES, CHIP, 15k, 1%, 0603
VISHAY, CRCW060315K0FKEA
19
4
R14, R15, R41, R45
RES, CHIP, 10, 1%, 0603
VISHAY, CRCW060310R0FKED
20
4
R17, R23, R40, R46
RES, CHIP, 10k, 1%, 0603
VISHAY, CRCW060310K0FKEA
21
2
R24, R29
RES, CHIP, 0, 0603
VISHAY, CRCW06030000Z0EA
22
2
R25, R27
RES, CHIP, 2.2 1%, 0603
VISHAY, CRCW06032R20FKEA
23
1
R28
RES, CHIP, 133k, 1%, 0603
VISHAY, CRCW0603133KFKEA
24
2
R42, R43
RES, CHIP, 10, 1%, 0603
VISHAY, CRCW060310R0FKED
25
2
RS1, RS2
RES, CHIP, 2mΩ, 2W, 1%, 2512
VISHAY, WSL25122L000FEA
26
1
U1
LTC3838EUHF, QFN, 38-LEAD,
LINEAR TECHNOLOGY LTC3838EUHF
Additional Demo Board Circuit Components
1
0
CIN2 (OPT)
CAP, OPT, SVP-F8
2
0
CIN4, CIN6 TO CIN8 (OPT)
CAP, OPT, 1210
3
0
C1, C2 ,C15, C17 (OPT)
CAP, OPT, 0603
4
0
COUT13 TO COUT16 (OPT)
CAP, OPT, 7343
5
0
Q5 TO Q8 (OPT)
MOSFET, OPTIMOS, PG-TDSON-8
6
0
R1, R3, R4, R6, R7, R9, R10, R19, R34,
R37, R44, R49, R50, R47, R48, R56 (OPT)
RES, CHIP, 0603
7
2
R51, R52
RES, CHIP, 10k, 1%, 0603
VISHAY, CRCW060310K0FKEA
8
2
R53, R54
RES, CHIP, 0.01, 1/2W, 1%, 2010
VISHAY, WSL2010R0100FEA
9
0
R18, R20, R26, R30, R32, R36 (OPT)
RES, CHIP, 0603
dc1801af
9
DEMO MANUAL DC1801A
PARTS LIST
Demo Board 1801A-B
ITEM
QTY
REFERENCE
PART DESCRIPTION
MANUFACTURER/PART NUMBER
Hardware/Components (For Demo Board Only)
1
20
E1 TO E20
TESTPOINT, TURRET, 0.095"
MILL-MAX, 2501-2-00-80-00-00-07-0
2
2
JP1 TO JP4
2mm SINGLE ROW HEADER, 3-PIN
SAMTEC, TMM-103-02-L-S
3
2
JP2, JP3
2mm SINGLE ROW HEADER, 4-PIN
SAMTEC, TMM-104-02-L-S
4
4
XJP1 TO XJP4
SHUNT
SAMTEC, 2SN-BK-G
5
6
J1 TO J6
JACK, BANANA
KEYSTONE, 575-4
6
2
J7, J8
CONN, BNC, 5 PINS
CONNEX, 112404
7
2
J9, J10
2mm SINGLE ROW HEADER, 2-PIN
SAMTEC, TMM-102-02-L-S
8
4
MH1 TO MH4
STAND-OFF, NYLON 0.25"
KEYSTONE, 8831 (SNAP ON)
dc1801af
10
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
1
E4
R39
R50
OPT
RUN1
E19
E16
C18
1uF
E15
EXTVCC
E14
2
R49
JMP1X3 OPT
VIN
TRK/SS1
C17
OPT
R44
OPT
VOUT2
R37
OPT
E10 0
E9
R10
OPT
R47
OPT
-A (DCR SENSE)
-B (RSENSE)
ASSY
*
15K
R30
C14
R31
15K
*
0.1uF
5
*
0
R57
OPT
INTVCC
0.22uF
1000pF
C3,
C16
C12
470pF
R28 133K
C11 47pF
*
R29
R24
WURTH 744355047 (0.47uH)
COILTRONICS FP1308R3-R44-R (0.44uH)
L1,L2
R26
R56
C6 47pF
C7 470pF
R21
FSW = 300kHz
2. INSTALL SHUNTS ON JUMPERS AS SHOWN.
1. ALL RESISTORS 0603.
ALL CAPACITORS ARE 0603.
0
C5 0.1uF
R17
10K
R13
15K
VFB2
R55
OPT
NOTE:
TIE SGND PIN TO PGND PAD
UNDERNEATH IC.
INTVCC
C2
OPT
R9
NOTES: UNLESS OTHERWISE SPECIFIED
GND
EXTVCC
PGOOD1
RUN1
ON
OFF
JP4
RUN1
TRK/SS1
CLKOUT
E8
3
2
R23
10K
INTVCC
PLLIN
FCM
SYNC
DCM
JP3
MODE
JP2 INTVCC
PHASMD
CLKOUT
120 DEG
2
90 DEG
3
60 DEG
TRK/SS2
C1
OPT
TRK/SS2
R8 0
R6
OPT
2.15K
OPT
R18,
R32
4
0
OPT
9
8
7
6
5
4
3
2
1
12
11
10
R20,
R36
R46
10K
C15 R40
OPT 10K
TRK/SS1
VRNG1
VRNG2
TRK/SS2
U1
LTC3838EUHF
R11
OPT
INTVCC
*
OPT
10
OPT
0
R14,R15, R24,
R41,R45 R29
*
R41
*
0
OPT
R26,
R30
R45
S1+ C16 S1-
VOUTSENSE1+
TRACK/SS1
ITH1
VRNG1
RT
SGND
CLKOUT
MODE/PLLIN
PHASEMD
VRNG2
C3
S2-
*
R14
R12
100K
INTVCC
BG2 29
27
R38
100K INTVCC
TG1 20
SW1 21
BG1 22
DRVCC1 23
VIN 24
PGND 25
INTVCC 26
EXTVCC
C9
0
R35
C10
0.1uF
1uF
3
R27
VOUT1
1
2.2
4
Q2
4
Q1
4
Q4
4
IOSTEP1-
IOSTEP1+
E22
E24
4
SW1
BSC010NE2LS
4
BSC050NE2LS
4
SW2
BSC010NE2LS
4
Q3
BSC050NE2LS
*
L1
R32
CIN3
22uF
16V
1210
*
*
*
R36
R34
OPT
CIN5
OPT
1210
S1+
CUSTOMER NOTICE
2512
*
RS1
VOUT2
1
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
E25
E23
SCALE = NONE
JW
DING L.
PCB DES.
APP ENG.
E3
VOUT2
E6
E5
J2
CIN1 J1
+ CIN2 + 180uF
OPT
16V
16SVP180MX
VIN
E7
COUT7 + COUT6 + COUT5 J3
330uF
100uF
330uF
2.5V
2.5V
6.3V
7343-D15T 7343-D15T
1206
J4
CIN7
(OPT)
35V
1210
R52
10K
VO2-
GND
VOUT2
1.5V / 20A
VO2+
VIN-
GND
VIN
4.5V - 14V
VIN+
R42
10
GND
PULSE2
VOUT1
E12
E11
VO1_SNS-
VO1_SNS+
J6
DATE:
N/A
SIZE
LTC3838EUHF
1
DEMO CIRCUIT 1801A
Tuesday, March 08, 2011
IC NO.
SHEET 1
OF 1
1
REV.
HIGH EFFIVIENCY DUAL OUTPUT STEP-DOWN DC-DC CONVERTER
1630 McCarthy Blvd.
Milpitas, CA 95035
Phone: (408)432-1900 www.linear.com
Fax: (408)434-0507
LTC Confidential-For Customer Use Only
+ COUT15 + COUT16
OPT
OPT
7343-D15T 7343-D15T
VOUT2
+ COUT13 + COUT14
OPT
OPT
7343-D15T 7343-D15T
VOUT1
ONLY ADD FOOTPRINTS
ON SOLDERMASK, DO
NOT SHOW IN
SCHEMATIC.
OPTIONAL COUT
R43
10
VOUT1
1.2V / 20A
+ COUT2 + COUT1
330uF
330uF J5
2.5V
2.5V
7343-D15T 7343-D15T
GND
TECHNOLOGY
E21
TITLE: SCHEMATIC
R54
0.01
2010
1
E18
COUT4 COUT3
100uF
100uF
6.3V
6.3V
1206
1206
Q10
SUD50N03-12P
VOUT2
APPROVALS
IOSTEP2-
IOSTEP2+
LOAD STEP
10mV / A
5% DUTY CYCLE MAX
J8
COUT8
100uF
6.3V
1206
CIN8
(OPT)
35V
1210
1
COUT1,2,5,6 = Sanyo 2R5TPE330M9
COUT3,4,7,8 = Murata GRM31CR60J107ME39L
CIN1 = Sanyo 16SVP180MX
CIN3,4 = Murata GRM32ER61C226KE20L
Q1,Q3 = Infineon BSC050NE2LS
Q2,Q4 = Infineon BSC010NE2LS
LOAD STEP CIRCUIT #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
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.
2
S2-
2512
R20
*
RS2
R19
OPT
S2+
CIN6
OPT
1210
DCR SENSE FILTER /
DIVIDER FOR PHASE 2
*
*L2
R18
CIN4
22uF
16V
1210
S1DCR SENSE FILTER /
DIVIDER FOR PHASE 1
Q6
OPT
Q5
OPT
Q8
OPT
Q7
OPT
PULSE1
E17
R51
GND
10K
E20
R53
0.01
2010
1
Q9
SUD50N03-12P
VOUT1
LOAD STEP
10mV / A
5% DUTY CYCLE MAX
J7
2
Note:
Make footprint for Q1-Q8 compatible with
LFPAK and PowerPAK MOSFETs.
LOAD STEP CIRCUIT #1
C13
D1
0.1uF CMDSH-3
R25
C8
2.2 4.7uF
16V
0805
D2
CMDSH-3
RUN2
R7 OPT
C4
0.1uF
RUN1
INTVCC
EXTVCC
0
INTVCC
R1 OPT
VRNG1
VRNG2
R4 OPT
VFB2
OPTIONAL COMPONENTS FOR SINGLE
OUTPUT, DUAL PHASE OPERATION
R16
3
0.000 Ohm 2512 TEPRO RN5326
0.002 Ohm 2512 VISHAY WSL25122L000FEA
RS1, RS2
R48
0
TG2 31
SW2 30
DRVCC2 28
*
TRACK/SS2
PGND 39
ITH2
S2+
*
R15
VOUTSENSE113
2
SENSE1+
14
R3
JMP1X3OPT
SENSE2- 36
SENSE115
E2 VIN
VFB2 38
VOUT2 35
VOUT1
16
JP1
RUN2
ON
OFF
SENSE2+ 37
RUN2 34
RUN1
17
RUN2
4
BOOST2 32
PGOOD1
18
3
1
4
1
4
1
PGOOD2 33
BOOST1
19
5
5
4
3
2
3
5
1
2
3
5
1
2
3
5
1
2
3
5
1
2
3
2
3
5
1
2
3
5
1
2
3
5
1
2
3
5
1
2
3
RUN2
5
4
3
2
E1
2
3
PGOOD2
A
B
C
D
DEMO MANUAL DC1801A
SCHEMATIC DIAGRAM
dc1801af
11
DEMO MANUAL DC1801A
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
dc1801af
12 Linear Technology Corporation
LT 0212 • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900
●
FAX: (408) 434-0507 ● www.linear.com
© LINEAR TECHNOLOGY CORPORATION 2012
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