DC2258A - Demo Manual

DEMO MANUAL DC2258A
LT3048
Low Noise Bias Generator
Description
Demonstration circuit 2258A features the LT®3048, a Boost
DC/DC Converter with integrated Schottky diode and LDO in
a 2mm × 2mm DFN package. This demo board is designed
to convert a 2.7V to 4.8V input to a 20V output at 10mA
to 25mA with low output ripple and noise. The LT3048
allows for the output to be programmed up to 23V. The
LT3048 is programmed for 1MHz switching frequency.
Performance Summary
PARAMETER
The LT3048 data sheet gives a complete description of
the part, operation, and application information. The data
sheet must be read in conjunction with this Quick Start
Guide for the demo circuit DC2258A.
Design files for this circuit board are available at
http://www.linear.com/demo/DC2258A
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.
Specifications are at TA = 25°C
CONDITIONS
MIN
Input Supply Range
Output Voltage Range
VIN = 2.7V, IOUT = 10mA
Switching Frequency
VIN = 4.8V, Load = 25mA
MAX
UNITS
4.8
V
19.5
20
20.5
V
0.7
1
1.3
MHz
1
mV
90
80
70
EFFICIENCY (%)
Output Ripple
TYP
2.7
60
50
40
30
20
10
2.7VIN
4.8VIN
2 4 6 8 10 12 14 16 18 20 22 24 26 28
OUTPUT CURRENT (mA)
DC2258A F01
Figure 1. Efficiency Curve
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DEMO MANUAL DC2258A
Quick Start Procedure
Demonstration circuit 2258A is easy to set up to evaluate the performance of the LT3048. Refer to 0 for proper
measurement equipment setup and follow the procedure
below:
NOTE. When measuring the output voltage ripple, connect
a X1 oscilloscope probe as shown in Figure 3.
1.Place jumper in the following positions: 1
Run
2.With power off, connect the input power supply to VIN
and GND.
3.Turn on the power at the input.
NOTE. Make sure that the input voltage does not exceed
4.8V.
4.Connect a 20mA load from VOUT to GND and check for
the proper output voltage. VOUT = 19.5V to 20.5V
If there is no output, temporarily disconnect the load to
make sure that the load is not set too high.
5.Once the proper output voltages are established, adjust
the input voltage and load within the operating range
and observe the output voltage regulation, ripple voltage, efficiency and other parameters.
Figure 2. Proper Measurement Equipment Setup
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DEMO MANUAL DC2258A
Quick Start Procedure
Figure 3. Output Ripple Measurement Technique
2mV/DIV
100ns
DC2258A F04
Figure 4. Output Voltage Ripple
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DEMO MANUAL DC2258A
Parts List
ITEM
QTY
REFERENCE
PART DESCRIPTION
MANUFACTURER/PART NUMBER
Required Circuit Components
1
1
C1
CAP., 4.7µF, X7R, 50V, 10%, 1206
MURATA, GRM31CR71H475KA12L
2
1
C2
CAP., 4.7µF, X7R, 25V, 10%, 0805
TDK, C2012X7R1E475K125AB
3
1
C3
CAP., 1000pF, C0G, 25V, 5%, 0603
MURATA, GRM1885C1E102JA01D
4
1
C4
CAP., 1µF, X7R, 25V, 10%, 0603
TDK, C1608X7R1E105K080AB
8
1
L1
IND., 22µH, PWR, WE-LQS, 20%
WURTH ELEKTRONIK, 74404024220
9
1
R1
RES., 1MΩ, 1%, 1/10W, 0603
VISHAY, CRCW06031M00FKEA
10
1
R2
RES., 66.5kΩ, 1%, 1/10W, 0603
VISHAY, CRCW060366K5FKEA
11
1
U1
I.C., DFN-2×2, 8-LEAD
LINEAR TECH., LT3048EDC#PBF
12
1
PCB, DC2258A
DEMO CIRCUIT 2258A
CAP., 1µF, X7R, 25V, 10%, 0603
TDK, C1608X7R1E105K080AB
Additional Demo Board Circuit Components
4
1
C5
Hardware: For Demo Board Only
5
4
E1, E2, E3, E4
TEST POINT, TURRET, .094", THT
MILL-MAX, 2501-2-00-80-00-00-07-0
6
1
JP1
CONN., HEADER, 1×3, 2mm
SULLINS, NRPN031PAEN-RC
7
1
XJP1
SHUNT, 2mm
SAMTEC, 2SN-BK-G
4
dc2258af
DEMO MANUAL DC2258A
A
15
18
20
28
2.7
3.3
3.6
4.8
2
R2
66.5K
R1
1M
3
LDOOUT
FB
5
6
4
BYP
BSTOUT
8
GND
4
5
E3
RUN ON
OFF
A
B
C
D
GND
C2
4.7uF
25V
0805 JP1
E1
VIN
2.7V - 4.8V
WE 74404024220
3
5
1
4
L1
22uH
2
7
1
2
EN
VIN
SW
U1
LT3048EDC
3
GND
3
9
C3
1nF
2
C1
4.7uF
50V
1206
C4
1uF
25V
C5
1uF
25V
*
Iout (mA)
Vin (V)
1
GND
E2
E4
1
VOUT
20V
*
B
C
D
Schematic Diagram
dc2258af
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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DEMO MANUAL DC2258A
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
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Linear Technology Corporation
LT 0815 • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
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●
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