DC1877A - Demo Manual

DEMO MANUAL DC1877A
LTC3630AEDHC
High Efficiency High Voltage 500mA
Synchronous Step-Down Converter
Description
Demonstration circuit 1877A is a 500mA output DC/DC
power supply featuring LTC®3630A (DFN package), with
4V to 76V input range. The LTC3630A operates in a high
efficiency Burst Mode® operation and includes internal
high and low side switches. The board provides jumper
selected output voltages of 1.8V, 3.3V, 5V and an option
for additional voltages. LTC3630A has internal soft-start
and a provision for increasing soft-start time.
Included on the board is an ON/OFF jumper that can
also be configured as a precision undervoltage lockout.
Additional pc pads are included for programming current
limit to optimize efficiency and for reducing output voltage
ripple and reducing component size. A terminal (FBO)
is available to allow multiple boards to be paralleled for
increasing output current.
Output voltage between 800mV and VIN can be programmed
using optional resistors. (Higher voltage output capacitors
may be required.)
The LTC3630A data sheet gives a complete description of
the operation and application information. The data sheet
must be read in conjunction with this demo manual.
Design files for this circuit board are available at
http://www.linear.com/demo/DC1877A
L, LT, LTC, LTM, Linear Technology, Burst Mode and the Linear logo are registered trademarks
of Linear Technology Corporation. All other trademarks are the property of their respective
owners.
Performance Summary
Table 1. Specifications are at TA = 25°C
PARAMETER
CONDITION
VALUE
Input Voltage Range
(1.8V, 3.3V Outputs)
4V to 76V
1.8V Output
VIN = 76V, IOUT = 500mA
1.8V ±2%
3.3V Output
VIN = 76V, IOUT = 500mA
3.3V ±2%
5V Output
VIN = 76V, IOUT = 500mA
5V ±2%
Maximum Output Current
VIN = 76V, VOUT = 5V
500mA
Typical Output Voltage Ripple
VIN = 76V, VOUT = 5V
84mVP-P
Typical Efficiency
(See Figure 3)
dc1877af
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DEMO MANUAL DC1877A
Quick Start Procedure
This demonstration circuit 1877A can be evaluated using
the setup shown in Figure 1.
1.Connect the DVMs to the input and output. Select 5V
setting using jumper JP1 (B position) and JP2 (A position), select ON position for JP3.
2.With input power supply set for 0V, connect the supply to
VIN and GND terminals using short (less than 10 inches)
leads, preferably twisted leads. Connect a suitable load
to VOUT and GND terminals.
3.Slowly increase the input power supply to 10V. Observe
output voltage and verify that it meets the specifications
in Table 1. Measure output voltage with and without the
load.
4.Move jumpers JP1 and JP2 to the other two fixed voltage settings and verify that each output voltage meets
the values as shown in Table 1.
5.Once the proper output voltages are established, adjust
the load and input voltage within the operating range
and observe the output voltage regulation, ripple voltage
and other parameters.
Notes:
1. IMPORTANT: 60V or higher voltage can result in an
electric shock if care is not taken. Also, hot plugging
the circuit to a power supply that has more than 40V
present at its output can produce a high voltage transient
exceeding the absolute maximum input voltage which
can damage the LTC3630A.
2. When measuring the input or output voltage ripple,
care must be taken to avoid a long ground lead on the
oscilloscope probe. Measure the input or output voltage
ripple by touching the probe tip directly across the VIN
or VOUT and GND terminals. See Figure 2 for proper
scope probe technique.
Load
Figure 1. Proper Measurement Equipment Setup
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DEMO MANUAL DC1877A
Quick Start Procedure
Circuit Options
RUN Pin Components: The converter is enabled when
the RUN pin voltage exceeds 1.21V and is disabled when
dropping below 1.1V. Pulling the RUN pin below 700mV
forces a low quiescent current shutdown. Moving JP3
to the ON position allows an internal current to pull the
RUN pin up to 5V. R1 and R2 are used to program input
undervoltage lockout. Select suitable resistors to divide
the input voltage down to the precision threshold voltage
levels that enable and disable the converter. Note that
the maximum voltage on the RUN pin is 6V, therefore a
nominal 5V zener diode (D1) is required to limit the RUN
pin voltage when high input voltages are used.
12VIN
36VIN
76VIN
0.01
0.1
LOAD CURRENT (A)
1
DC1788a F03a
EFFICIENCY (%)
ISET Components: C3, R3 and R4 are used to provide a
number of features and circuit enhancements such as,
output current limit, input current limit, optimizing output
ripple voltage reduction and efficiency improvement. R4
sets maximum output current, see Figure 2 in LTC3630A
data sheet, leave open for maximum load current. R3 and
R4 can be used to set input current limit. C3 is used to
reduce output voltage ripple and optimize efficiency. See
data sheet for details.
100
3.3VOUT
95
90
85
80
75
70
65
60
55
50
45
40
35
30
0.001
12VIN
36VIN
76VIN
0.01
0.1
LOAD CURRENT (A)
1
DC1788a F03b
EFFICIENCY (%)
Optional Output Voltage: Additional output voltages can
be programmed by selecting proper resistors for the R6
and R7 feedback network. C5 is a feedforward capacitor
to optimize transient response and increase stability. Both
JP1 and JP2 must be in A position if R6 and R7 are used.
The 10V rated output capacitors should be replaced with
suitable voltage ratings.
EFFICIENCY (%)
Detailed information is contained in the data sheet.
100
1.8VOUT
95
90
85
80
75
70
65
60
55
50
45
40
35
30
0.001
100
5VOUT
95
90
85
80
75
70
65
60
55
50
45
40
35
30
0.001
12VIN
36VIN
76VIN
0.01
0.1
LOAD CURRENT (A)
1
DC1788a F03c
Figure 3. Efficiency Curves
Figure 2. Measuring Input or Output Voltage Ripple
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DEMO MANUAL DC1877A
Parts List
ITEM
QTY
REFERENCE
PART DESCRIPTION
MANUFACTURER/PART NUMBER
Required Circuit Components
1
1
C1
CAP, 0.22µF, X7R, 100V, 10%, 0805
MURATA, GRM21AR72A224KAC5L
2
1
C2
CAP, 4.7µF, X7R, 100V, 20%, 2220
TDK, C5750X7R2A475M230KA
3
1
C3
CAP, 220pF, X7R, 50V, 10%, 0603
AVX, 06035C221KAT2A
4
1
C4
CAP, 0.047µF, X7R, 25V, 10%, 0603
AVX, 06033C473KAT2A
5
2
C6, C7
CAP, 100µF, X5R, 10V, 20%, 1210
MURATA, GRM32ER61A107ME20L
6
1
C9
CAP, 0.1µF, X7R, 25V, 10%, 0603
AVX, 06033C104KAT2A
7
1
L1
IND, POWER, 68µH, 1.6A, 30%, SMD
SUMIDA, CDRH105RNP-680NC
8
1
R4
RES, 220k, 1/10W, 5%, 0603
VISHAY, CRCW0603220KJNEA
9
1
R5
RES, 4.7Ω, 1/8W, 5%, 0805
VISHAY, CRCW08054R70JNEA
10
2
R6
RES, 0Ω, 1/10W, 0603
VISHAY, CRCW06030000Z0EA
11
1
U1
IC, LTC3630AEDHC, DFN 5mm x 3mm
LINEAR TECHNOLOGY, LTC3630AEDHC#PBF
Additional Demo Board Circuit Components
1
0
C5
CAP, OPTION, 0603
2
0
C8, C10, C11
CAP, OPTION, 1210
3
0
D1
DIODE, OPTION
4
0
R1, R2, R3, R7
RES, OPTION, 0603
Hardware: For Demo Board Only
1
6
E1, E2, E3, E4, E5, E6
TEST POINT, TURRET, 0.094" MTG. HOLE
MILL-MAX, 2501-2-00-80-00-00-07-0
2
3
JP1, JP2, JP3
CONN, HEADER, 1 x 3, 2mm
SAMTEC, TMM-103-02-L-S
3
3
JP1, JP2, JP3
SHUNT, 2mm
SAMTEC, 2SN-BK-G
4
1
PCB, DC1877A
DEMO CIRCUIT 1877A
5
2
STENCIL, DC1877A (TOP AND BOTTOM)
STENCIL DC1877A
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4
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
E5
E4
R5
4.7
0805
VIN
OPT
D1
C1
220nF
100V
0805
R3
OFF
R2
OPT ON
OPT
R1
OPT
2
JP3
R4
220k
3
1
2
B
A
A
B
A
3.3V
5.0V
EXT. R
5
3. FOR 5V OUTPUT, VIN RANGE IS 6V-76V.
A
B
B
1.8V
JP2
JP1
VOUT
VIN
11
12
5
3
NC
NC
NC
NC
ISET
FBO
RUN
VIN
SS
VPRG2
VPRG1
VFB
SW
CUSTOMER NOTICE
2
C3
4
220pF 13
15
C2
4.7uF
100V
2220
U1
LTC3630AEDHC
10
6
7
9
1
3
4
3
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
L1
2
B A
2
B A
1
1
2
JP2
2
JP1
R7
OPT
ECO
C5
OPT
1
SCALE = NONE
DESCRIPTION
C10
OPT
1210
VOUT
C6
100uF
10V
1210
C8
OPT
1210
E2
DATE
7-9-13
E6
E3
GND
GND
VOUT
C9
1.8V/3.3V/5V
0.1uF 500mA
Charlie Z.
APPROVED
1
DATE:
2
Friday, December 12, 2014
1
SHEET 1
OF 1
HIGH EFFICIENCY, 76V, 500mA SYNCHRONOUS
STEP-DOWN CONVERTER
IC NO.
REV.
SIZE
LTC3630AEDHC
1
N/A
DEMO CIRCUIT 1877A
1630 McCarthy Blvd.
Milpitas, CA 95035
Phone: (408)432-1900 www.linear.com
Fax: (408)434-0507
LTC Confidential-For Customer Use Only
C11
OPT
1210
C7
100uF
10V
1210
PRODUCTION
REVISION HISTORY
TECHNOLOGY
REV
2
Charlie Z. TITLE: SCHEMATIC
HZ
APPROVALS
C4
47nF
3
3
R6
0
VOUT
68uH
SUMIDA CDRH105
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.
VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL
APPLICATION. COMPONENT SUBSTITUTION AND PRINTED
APP ENG.
CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT
PERFORMANCE OR RELIABILITY. CONTACT LINEAR
TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
1. ALL RESISTORS AND CAPACITORS ARE 0603.
NOTE: UNLESS OTHERWISE SPECIFIED
FBO
GND
VIN
4V - 76V
E1
4
GND
8
GND
16
GND
14
GND
17
D
5
A
B
C
D
DEMO MANUAL DC1877A
Schematic Diagram
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DEMO MANUAL DC1877A
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
dc1877af
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Linear Technology Corporation
LT 0115 • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900
●
FAX: (408) 434-0507 ● www.linear.com
 LINEAR TECHNOLOGY CORPORATION 2015
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