DC441A - Demo Manual

QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 441
1.25A SYNCHRONOUS BUCK REGULATOR
LTC3411
DESCRIPTION
Demonstration circuit 441 is a constant-frequency stepdown converter, using the LTC3411 monolithic synchronous buck regulator. The DC441 has an input voltage
range of 2.65V to 5.5V, and is capable of delivering up to
1.25A of output current. In Burst Mode operation, the
DC supply current is typically only 240µA at no load, and
less than 1µA in shutdown. In switching-noise sensitive
applications, pulling the MODE pin to SGND inhibits
Burst Mode operation. These features, plus the
LTC3411 coming in a small 10-Pin MS package and having an operating frequency of 1MHz (allowing the exclusive use of low profile surface mount components),
make the DC441 demo board an ideal circuit for use in
battery-powered, hand-held applications.
Design files for this circuit board are available. Call
the LTC factory.
QUICK START PROCEDURE
Demonstration circuit 441 is easy to set up to evaluate
the performance of the LTC3411. Refer to Figure 1 for
proper measurement equipment setup and follow the
procedure below:
NOTE: When measuring the output ripple, see Figure 2
for proper scope probe technique.
1. Select the desired output voltage using jumper JP2.
The fixed output voltages are 1.8V, 2.5V, and 3.3V (as
shown). There is also an option to set the output voltage to a custom value by inserting a resistor into the
RFB5 pads next to jumper JP2.
2. Connect the input power supply to the Vin and GND
plug Vin or increase Vin over the rated maximum
supply voltage of 5.5V, or the part may be damaged.
3. Connect the load between the Vout and GND termi-
nals on the right-side of the board.
4. Select the desired operating mode using JP1. To se-
lect pulse-skipping mode, tie to ground by inserting
the jumper into the rightmost position. Inserting the
jumper into the leftmost position connects the pin to
Vin, which allows Burst Mode operation.
5. To shut down the circuit, connect the SHDN/RT pin to
SVIN by inserting the JP3 jumper into the rightmost
position.
terminals on the left-side of the board. Do not hot-
+
+
–
–
–
+
–
+
+
VS
+
LOAD
–
–
Figure 1. Proper Measurement Equipment Setup
GND
VIN
Figure 2. Scope Probe Placement for Measuring Output Ripple
1
5
4
3
2
1
E7
PGood
9
Ith
10
SD/RT
2
Rs2
1M
Rset
324K
JP3
3
4.7M
Rfb3
412K, 1%
Rfb2
698K, 1%
JP2
Rfb4
280K, 1%
Opt.
3.3V
E4
GND
OFF ON
E6
RPG RFB1
RSW CFFW
C1 COUT2
RC
CC
GND
COUT1
CIN2
CIN1
L1
U1
C
1.8V
2.5V
E5
GND
B
Cout3
0.1uF
1
7
Rsd
2
E2
Rfb1
887K, 1%
1%
Rfb5
Opt.
R1
10K
SYNC
/MODE
6.3V
Cffw
10pF
Opt.
Cc
1000pF
Burst Mode
C
C1
Opt.
Cout2
1uF
2
PGND
Sy/Mode
Rc
16.2K
1
2
SGND
Cbyp
Opt.
Rsw
Opt.
8
1
Vfb
1
SVin
4
PGood
7
3
JP1
8
0
Rs1
1M
Pulse-skip 3
100K
3
Rfilt
2.2uH
D1
Cout1
22uF
Opt.
6
Cin1
10uF
6.3V
Cin2
1uF
Opt.
Vout
3.3V/2.5V/1.8V
1.25A
Cout4
Opt.
E3
4
SW
5
Cin3
Opt.
PVin
1
6
Rpg
L1
2
Vin E1 VIN
2.65V-5.5V
Cin4
47uF
16V
D
U1
LTC3411EMS
5
D
B
RSET
PCB SILKSCREEN
CONTRACT NO.
APPROVALS
DRAWN
A
June Wu
DATE
6/28/01
TECHNOLOGY
TITLE
ENGINEER Tom Gross
A
LTC3411EMS
CHECKED
APPROVED
1630 McCarthy Blvd.
Milpitas, CA 95035
Phone: (408)432-1900
Fax: (408)434-0507
Buck Regulator: 2.65V-5.5V->1.8V, 2.5V, or [email protected](max)
6/28/01
SIZE CAGE CODE
DESIGNER
DWG NO
REV
A
DEMO DC441A
Monday, March 11, 2002
5
4
3
SCALE:
2
FILENAME:
SHEET
1
1
OF
1
Bill Of Material
Demo Bd. #441A
Linear Technology Corporation
LTC3411EMS
6/17/2005
11:57 AM
Item Qty Reference
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
0
1
1
1
1
0
1
1
0
0
7
2
1
3
1
1
1
1
1
1
1
0
1
1
1
0
2
1
1
1
1
1
Cbyp,Cout2,Cin2 (OPT)
Cc
Cffw
Cout1
Cin1
Cout4,Cin3 (OPT)
Cout3
Cin4
C1 (OPT)
D1 (OPT)
E1-E7
JP1,JP3
JP2
JP1,JP2,JP3
L1
Rc
R1
Rfb1
Rfb2
Rfb3
Rfb4
Rfb5 (OPT)
Rfilt
Rpg
Rset
Rsw (OPT)
Rs1,Rs2
Rsd
U1
Part Description
CAP.,
0603
CAP., X7R, 1000pF, 25V, 20% 0402
CAP., NPO, 10pF, 50V, 10% 0402
CAP., X5R, 22uF, 6.3V, 10% 1210
CAP., X5R, 10uF, 6.3V, 10% 1206
CAP.,
6032, 7343
CAP., X7R, 0.1uF, 16V, 20% 0603
CAP., TANT., 47uF, 16V, 20% 6032
CAP.,
402
DIODE,
SMA
TESTPOINT, TURRET, .094"
0.079 SINGLE ROW HEADER 3 PIN
0.079X4 DOUBLE ROW HEADER
SHUNT,
INDUCTOR, 2.2uH D52LC
RES.,CHIP, 16.2K, 1/16W, 5%, 0402
RES.,CHIP, 10K, 1/16W, 5%, 0402
RES.,CHIP, 887K, 1/16W, 1% 0402
RES.,CHIP, 698K, 1/16W, 1% 0402
RES.,CHIP, 412K, 1/16W, 1% 0402
RES.,CHIP, 280K, 1/16W, 1% 0402
RES.,
1% 0402
RES.,CHIP, 0, 1/16W, 0402
RES.,CHIP, 100K, 1/16W, 5% 0402
RES.,CHIP, 316K, 1/16W, 1% 0402
RES.,
0402
RES.,CHIP, 1M, 1/16W, 5% 0402
RES.,CHIP, 4.7M, 1/16W, 5% 0402
I.C., LTC3411, MS10
PRINTED CIRCUIT BOARDS
STENCIL
S/F
6-Boards to Alan 3/15/02
Page 1 - of - 1
Manufacture / Part #
AVX, 04023C102MAT
AVX, 04025A100KAT
MURATA, GRM32DR60J226KA01
MURATA, GRM31CR60J106KC01
AVX, 0603YC104MAT
AVX, TAJC476M016R
MILL-MAX, 2501-2
COMM CON, 2802S-03-G1
COMM CON, 2202S-08-G1
COMM CON, CCIJ2MM-138G
TOKO, A914BYW-2R2M
AAC, CR05-1622FM
AAC, CR05-103JM
AAC, CR05-8873FM
AAC, CR05-6983FM
AAC, CR05-4123FM
AAC, CR05-2803FM
AAC, CJ05-000M
AAC, CR05-104JM
AAC, CR05-3163FM
AAC, CR05-105JM
AAC, CR05-475JM
LINEARL, LTC3411EMS
DEMO BOARD DC441A
STENCIL DC441A
S / Frame, #10679, @ Flairis
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