DC1764A - Demo Manual

DEMO MANUAL DC1764A
LTC3122EDE
High Efficiency 15V 2.5A
Synchronous Step-Up Converter
DESCRIPTION
Demonstration circuit 1764A is a 5.5V input, 12V output
at 800mA DC/DC power supply featuring the LTC®3122.
The IC includes internal high and low side 2.5A switches
and features selectable PWM or Burst Mode® operation
for high efficiency at low output current. The board operates from an input voltage as low as 1.8V and continues
to operate down to 500mV once started. The output is
fixed at 12V although other voltages between 2.2V and
15V can be selected by resistor changes.
The IC includes soft-start and input current limit, adjustable switching frequency with the ability to synchronize
to an external clock, and output overvoltage protection
with output disconnect.
PERFORMANCE SUMMARY
PARAMETER
Included on the board are jumpers for ON/OFF and operating MODE, PWM or BURST. Terminals are included for
connecting VIN and VOUT as well as ON/OFF and SYNC.
The LTC3122 data sheet gives a complete description of the
IC operation and application information. The data sheet
must be read in conjunction with this quick start guide.
Design files for this circuit board are available at
http://www.linear.com/demo
L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks
of Linear Technology Corporation. All other trademarks are the property of their respective
owners.
Specifications are at TA = 25°C
CONDITION
Input Voltage Range
VALUE
1.8V to 5.5V
VIN = 5V, VOUT Load = 800mA
12V ±3%
Output Current
VIN = 5V, VOUT = 12V
800mA
Output Voltage Ripple (PWM Mode)
VIN = 5V, VOUT = 12V, VOUT Load = 500mA
40mVP-P
Output Voltage Ripple (Burst Mode Operation)
VIN = 5V, VOUT = 12V, VOUT Load = 50mA
Output Voltage
Switching Frequency
200mVP-P
1MHz ±15%
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DEMO MANUAL DC1764A
QUICK START PROCEDURE
This Demonstration circuit 1764A can be evaluated using
the setup shown in Figure 1.
1. Connect voltmeters to VIN and VOUT, select upper positions for jumper JP1 (ON) and JP2 (PWM).
2. With input power supply set for 0V, connect the supply
to VIN and GND terminals.
3. Slowly increase the input power supply to 1.8V. Observe
output voltage and verify that it meets the specifications
in the Performance Summary table.
6V, 3A
Adjustable
Power Supply
V
+
4. Connect a suitable load resistor or active load to the
output terminals and verify that it meets specifications
in the Performance Summary table.
5. Use a scope to monitor the output voltage ripple in
both PWM mode and Burst Mode operation by moving
the mode jumper JP2 to the appropriate position. See
Figure 4 for correct method for evaluating output ripple.
6. Note: If jumper JP2 is set for Burst Mode operation,
maximum output current is limited to approximately
100mA at 5VIN.
-
A
V
A
Load
+
Figure 1. Proper Measurement Equipment Setup
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2
DEMO MANUAL DC1764A
QUICK START PROCEDURE
100
90
Burst Mode
OPERATION
90
80
70
EFFICIENCY (%)
EFFICIENCY (%)
80
100
60
50
40
PWM MODE
60
50
30
20
20
10
10
1
10
100
LOAD CURRENT (mA)
1000
PWM MODE
40
30
0
0.1
Burst Mode
OPERATION
70
0
0.1
1
dc1764a F02
Figure 2. Efficiency VIN = 2V
10
100
LOAD CURRENT (mA)
1000
dc1764a F03
Figure 3. Efficiency VIN = 5V
Figure 4. Measuring Output Voltage Ripple
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DEMO MANUAL DC1764A
PARTS LIST
ITEM
QTY
REFERENCE
PART DESCRIPTION
MANUFACTURER/PART NUMBER
Required Circuit Components
1
1
C1
CAP CER, 10μF 10V 10% X5R 1206
TDK, C3216X5R1A106K
2
1
C2
CAP CER, 10μF 50V X7R 10% 0603
TDK, CGA3E2X7R1H104K
3
1
C3
CAP CER, 4.7μF 25V X5R 0805
TDK, C2012X5R1E475K
4
1
C5
CAP CER, 22μF 25V X5R 1210
MURATA, GRM32ER61E226KE15L
5
1
C7
CAP CER, 1μF 25V 10% X7R 0603
TDK, CGA3E1X7R1E105K
6
1
C8
CAP CER, 330pF 50V X7R 10% 0402
TDK, C1005X7R1H331K
7
1
L1
INDUCTOR, 4.7μH
COILCRAFT, XAL4030-472MEB
8
1
R1
RES, 1.00M 1/16W 1% SMD 0402
PANASONIC, ERJ-2RKF1004X
9
1
R2
RES, 57.6k 1/10W 1% 0402 SMD
PANASONIC, ERJ-2RKF5762X
10
1
R4
RES, 1.02M 1/16W 1% 0402 SMD
VISHAY, CRCW04021M02FKTD
11
1
R5
RES, 113k 1/10W 1% 0402 SMD
PANASONIC, ERJ-2RKF1133X
12
1
R6
RES, 86.6k 1/10W 1% 0402 SMD
VISHAY, CRCW040286K6FKED
13
1
U1
15V, 2.5A SYNCHRONOUS BOOST DC/DC CONVERTER
LINEAR TECH;, LTC3122EDE
Additional Demo Board Circuit Components
1
0
C4, C9
CAP CER, 0402
OPT
2
0
C6
CAP CER, 1210
OPT
3
0
R3
RES, 0402
OPT
Hardware: For Demo Board Only
1
6
E1-E6
TURRET, 0.09 DIA
MILL-MAX, 2501-2-00-80-00-00-07-0
2
2
JP1, JP2
JMP, 3 PIN 1 ROW 0.079CC
SAMTEC, TMM-103-02-L-S
3
2
XJP1, XJP2
SHUNT, 0.079" CENTER
SAMTEC, 2SN-BK-G
4
4
STAND OFF
STAND-OFF, NYLON 0.50" Tall
KEYSTONE, 8832 (SNAP ON)
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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
2
3
VCC
C1
10uF
10V
1206
VIN
R1
1M
1%
5
2. INSTALL SHUNTS AS SHOWN.
1. ALL RESISTORS ARE 0402 AND CAPACITORS ARE 0603.
NOTE: UNLESS OTHERWISE SPECIFIED
MODE
1
PWM
2
3
BURST
JP2
E4
JP1
RUN
E3
E2
SYNC
ON
OFF
RUN
GND
E1
VIN
1.8V - 5.5V
4
4
R2
57.6k
1%
L1
2 PGND
10 GND
C3
4.7uF
0805
VCC
VCC 5
VC 7
FB 8
SW 1
CAP 12
VOUT 11
R6
86.6k
1%
C8
330pF
0402
C2
0.1uF
50V
CUSTOMER NOTICE
3
3
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
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.
4 PWM/SYNC
6 RT
3 VIN
9 SHDN/
U1
LTC3122EDE
XAL4030
4.7uH
GND
13
5
FRAN H.
2
SCALE = NONE
NC
PCB DES.
APP ENG.
APPROVALS
C9
OPT
0402
1%
R3
OPT
C4
OPT
0402
2
2
REV
DESCRIPTION
TECHNOLOGY
C5
22uF
25V
1210
C7
1uF
25V
E6
E5
GND
VOUT
12V
500mA
FRAN H.
APPROVED
DATE
05-16-12
1630 McCarthy Blvd.
Milpitas, CA 95035
Phone: (408)432-1900 www.linear.com
Fax: (408)434-0507
LTC Confidential-For Customer Use Only
C6
OPT
1210
VOUT
PRODUCTION FAB
DATE:
N/A
SIZE
LTC3122EDE
DEMO CIRCUIT 1764A
05 - 16 - 12
IC NO.
1
SHEET 1
OF
1
2
REV.
15V, 2.5A SYNCHRONOUS BOOST DC / DC CONVERTER
TITLE: SCHEMATIC
R5
113K
1%
R4
1.02M
1%
__
ECO
1
REVISION HISTORY
A
B
C
D
DEMO MANUAL DC1764A
SCHEMATIC DIAGRAM
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DEMO MANUAL DC1764A
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
dc1764af
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Linear Technology Corporation
LT 0812 • 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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