DC1667A - Demo Manual

DEMO MANUAL DC1667A
LTC3600
16V, 1.5A Synchronous
Step-Down Regulator with
Programmable Reference
DESCRIPTION
Demonstration circuit DC1667A is a step-down DC/
DC converter using LTC®3600 monolithic synchronous
buck regulator. DC1667A has an input voltage range of
4.5V to 15V, and is capable of delivering up to 1.5A of
output current. The output voltage of the DC1667 can be
set by a single resistor from 0V to (VIN – 0.5)V. At light
load conditions, DC1667 can operate in discontinuous
mode to improve the efficiency. During shutdown mode,
LTC3600 consumes less than 1µA. The switching frequency
of LTC3600 is programmable from 200kHz to 4MHz.
DC1667A uses low profile surface mount components.
PERFORMANCE SUMMARY
PARAMETER
These features and the availability of LTC3600 in a 12-lead
DFN/MSOP package, make it ideal for use in point-of-load
power supplies, battery-powered equipments and voltage
tracking systems. The LTC3600 data sheet must be read
in conjunction with this demo manual for working on or
modifying the demo circuit DC1667A.
Design files for this circuit board are available at
http://www.linear.com/demo/DC1667A
L, LT, LTC, LTM, µModule, 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
Input Voltage Range
Default Output Voltage VOUT
VALUE
4.5V to 15V
VIN = 4.5V to 15V, IOUT = 0A to 1.5A, JP10: CCM
1.215V ± 2% (1.19V to 1.24V)
Maximum Continuous Output Current
1.5A
Default Operating Frequency
1MHz
Typical Output Voltage Ripple
VIN = 5V, VOUT = 1.2V, IOUT = 1.5A, fSW = 1MHz
<10mV (See Figure 4)
Efficiency
VIN = 5V, VOUT = 1.2V, IOUT = 1.5A, fSW = 1MHz
78% (See Figure 3)
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DEMO MANUAL DC1667A
QUICK START PROCEDURE
Demonstration circuit DC1667A is easy to set up to evaluate
the performance of the LTC3600. Please refer to Figure 1
for proper measurement equipment setup and follow the
procedure below:
1.Place jumpers in the following positions for a typical
1.2V output application:
JP2
JP7
JP8
JP9
JP10
1.2V
COMP
PGOOD
RUN
MODE/SYNC
1.2V
EXT
DIS
OFF
CCM
2.With power off, connect the input power supply, load
and meters as shown in Figure 1. Preset the load to 0A
and VIN supply to 5V.
3.Turn on the power supply at the input. Measure and
make sure the input voltage is 5V. Turn on the circuit
by inserting the shunt in header JP9 to the ON position.
The output voltage should be 1.215V ± 2% (1.19V to
1.24V).
4.Once the proper output voltage is established, adjust the
load within the operating range and observe the output
voltage regulation, output voltage ripple, efficiency and
other parameters. Refer to Figure 2 for proper input/
output voltage ripple measurement.
5.To select other output voltages, LTC3600 has to be shut
down by putting RUN pin jumper to the OFF position or
turning off the input supply. After the IC is shut down,
move the shunt to other output voltage selections, such
as 1.8V or 3.3V, and repeat tests 1 through 4. The output
voltage tolerance should remain at VOUT ± 2%.
LOAD (0A TO 1.5A)
VIN
4.5V TO 15V
+
+
–
–
–
–
+
VOUT
+
+
–
DC1667A F01
Figure 1. Proper Equipment Measurement Setup
INPUT OR OUTPUT CAPACITOR
Figure 2. Scope Probe Placements for Measuring Input or Output Ripple
2
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DEMO MANUAL DC1667A
QUICK START PROCEDURE
100
90
EFFICIENCY (%)
80
70
60
50
40
30
5VIN , 1.2VOUT DCM
12VIN , 1.2VOUT DCM
5VIN , 1.2VOUT CCM
12VIN , 1.2VOUT CCM
20
10
0
0.01
0.1
LOAD CURRENT (A)
1
DC1667A F03
Figure 3. Measured Efficiency (VOUT = 1.2V)
20MHz BW LIMIT
VOUT
10mV/DIV
SWITCHING NODE
5V/DIV
1µs/DIV
DC1667A F04
Figure 4. Measured Output Voltage Ripple at 5V Input,
1.2V Output, 1.5A with Standard Demo Circuit Default Setup
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DEMO MANUAL DC1667A
PARTS LIST
ITEM
QTY
REFERENCE
PART DESCRIPTION
MANUFACTURER/PART NUMBER
Required Circuit Components
1
1
CIN2
Capacitor, X5R 22µF 16V 20% 1210
TDK C3225X5R1C226M
2
1
COUT1
Capacitor, X5R 47µF 6.3V 20% 1210
Taiyo Yuden JMK325BJ476MM-T
3
1
C3
Capacitor, X5R 4.7µF 16V 20% 0805
Taiyo Yuden EMK212BJ475MG
4
1
C4
Capacitor, X7R 0.1µF 25V 10% 0603
AVX 06033C104KAT2A
5
1
L1
Inductor, 2.2µH IHLP-2020CZ-01
Vishay IHLP-2020CZ-ER 2R2M01
6
1
R2
Resistor, Chip 24.3K 0.06W 1% 0603
Vishay CRCW060324K3FKEA
7
1
R9
Resistor, Chip 36.5K 0.06W 1% 0402
Vishay CRCW040236K5FKED
8
1
U1
I.C., Voltage Regulator DFN(12)(DD) 3mm × 3mm
Linear Technology Corporation LTC3600EDD
Additional Demo Board Circuit Components
1
1
CIN1
Capacitor, Tantalum 3.3µF 35V 20% 6032
AVX TAJW335M035R
2
1
CIN3
Capacitor, X5R 22µF 16V 20% 1210
TDK C3225X5R1C226M
3
2
COUT2, COUT3
Capacitor, 1210
4
1
C1
Capacitor, NPO 68pF 50V 10% 0603
5
1
C2
Capacitor, 0402
6
1
C5
Capacitor, X7R 0.01µF 16V 20% 0402
7
1
C6
Capacitor, 0805
8
1
RSD
Resistor, Chip 1M 0.06W 5% 0603
Vishay CRCW06031M00JNEA
9
1
R1
Resistor, Chip 16.2k 0.06W 1% 0603
Vishay CRCW060316K2FKEA
10
1
R3
Resistor, Chip 35K7 0.06W 1% 0603
Vishay CRCW060335K7FKEA
11
1
R4
Resistor, Chip 66.5k 0.06W 1% 0603
Vishay CRCW060366K5FKEA
12
1
R5
Resistor, 0603
13
1
R6
Resistor, Chip 56k 0.06W 5% 0603
Vishay CRCW060356K0JKEA
14
1
R7
Resistor, Chip 100k 0.06W 5% 0603
Vishay CRCW0603100KJNEA
15
1
R8
Resistor, 0402
16
2
R10, R11
Resistor, 0603
17
1
R12
Resistor/Jumper, Chip 0Ω 1/8W 1A 0805
Vishay CRCW08050000ZOEA
AVX 06035A680KAT1A
AVX 0402YC103MAT2A
Hardware-For Demo Board Only
1
7
E1-E7
Turret, Testpoint .062 Thick Board
Mill Max 2501-2-00-80-00-00-07-0
2
4
JP1–JP3, JP5
Jumper, 2 Pins 2mm Ctrs.
Samtec TMM-102-02-L-S
3
1
JP6
4
3
JP7–JP9
Headers, Single Row 3 Pins 2mm Ctrs.
Samtec TMM-103-02-L-S
5
1
JP10
Headers, Double Row 2mm × 3 2mm Ctrs.
Samtec TMM-103-02-L-D
6
5
XJP2, XJP7–XJP10
Shunt, 2mm Ctrs.
Samtec 2SN-BK-G
7
1
Stencil
Stencil DC1667A
4
Samtec TMM-102-02-L-S
dc1667afa
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.
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B
A
1. ALL RESISTORS 0402.
2. ALL CAPACITORS 0402.
B
NOTE: UNLESS OTHERWISE SPECIFIED.
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A
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JEFF Z.
SCALE = NONE

PCB DES.
APP ENG.
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D
DATE
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DATE:
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IC NO.
SHEET 1
OF 1
4
REV.
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APPROVED
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TECHNOLOGY
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TITLE: SCHEMATIC
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APPROVALS
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VOUT
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+ 

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VIN
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INTVCC
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
DESCRIPTION
REVISION HISTORY


THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
C
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ECO
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INTVCC
CUSTOMER NOTICE

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


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.

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DEMO MANUAL DC1667A
SCHEMATIC DIAGRAM
dc1667afa
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DEMO MANUAL DC1667A
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
6
dc1667afa
Linear Technology Corporation
LT 1214 REV A • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900
●
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