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DEMO MANUAL DC1195A
DESCRIPTION
LTM8023 36V, 2A DC/DC
µModule
®
Regulator
Demonstration circuit 1195 features the LTM
®
8023, a
step-down regulator preconfigured to deliver 3.3V at up
to 2A from a 5V to 36V input supply. The LTM8023 is a
step-down converter, so minimum amount of headroom
is required to keep the output in regulation. In addition,
the input voltage required to turn on is higher than that
required to run (see Minimum Input Voltage section in the
data sheet for detail). The optional Burst Mode
®
operation
of LTM8023 supports high efficiency and low output ripple
at light load conditions.
L, LT, LTC, LTM, Linear Technology, Burst Mode, µModule and the Linear logo are registered
trademarks of Linear Technology Corporation. All other trademarks are the property of their
respective owners.
PARAMETER CONDITION VALUE
Input Voltage Range 5V (Note 1) to 36V
Output Voltage VOUT 3.3V
Maximum Output Current 2A
Typical Switching Frequency 600kHz
Note 1: The circuit requires more than 5V to run at full load. See Figure 1 and the data sheet for detail.
BOARD PHOTO
PERFORMANCE SUMMARY
The LTM8023 data sheet gives a complete description of the
part, operation and application information. The LTM8023
data sheet must be read in conjunction with this manual
to operate or modify demo circuit 1195.
Design files for this circuit board are available at
http://www.linear.com/demo
(TA = 25°C)
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DEMO MANUAL DC1195A
QUICK START PROCEDURE
Demonstration circuit 1195 is a simple way to evaluate
the performance of the LTM8023. Refer to Figure 2 and
Figure 3 for proper measurement equipment setup and
follow the procedure below:
NOTE. 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 3 for proper scope
probe technique.
1. Place JP1 on the ON position.
2. With power off, connect the input power supply to VIN
and GND.
3. Turn on the power at the input. The output voltage
should rise to 3.3V.
4. Once the proper output voltage is established, adjust
the load within the operating range and observe the
output voltage regulation, ripple voltage, efficiency and
other parameters.
Figure 1. Load Current vs Input Voltage (3.3VOUT)
INPUT VOLTAGE (V)
LOAD CURRENT (mA)
0
1195 F01
500
2500
2000
1500
1000
0 10 20 30 40
25°C
40°C
85°C
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DEMO MANUAL DC1195A
QUICK START PROCEDURE
Figure 2. Proper Measurement Equipment Setup
Figure 3. Measuring Input or Output Ripple
GNDVIN
Figure 4. Efficiency
OUTPUT CURRENT (A)
0.01 0.1 1
EFFICIENCY (%)
60
50
55
1195 F04
70
65
90
85
80
75
VOUT = 3.3V
5VIN
12VIN
24VIN
36VIN
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DEMO MANUAL DC1195A
PARTS LIST
ITEM QUANTITY REFERENCE-DESCRIPTION DESCRIPTION MANUFACTURER’S PART NUMBER
1 1 CIN Cap, 22µF 20% 50V Alum Sanyo 50CE22BS
2 1 C1 Cap, 2.2µF 10% 50V X7R, 1206 Murata GRM31CR71H225KA88L
3 1 C2 Cap, 22µF 20% 10V X5R, 1206 Taiyo Yuden LMK316BJ226ML-T
4 1 C3 Cap, 0.1µF 10% 50V X7R, 0603 TDK C1608X7R1H104K
5 5 E1, E2, E4, E5, E9 Turret Mill-Max 2501-2-00-80-00-00-07-0
6 4 E3, E6, E7, E8 Turret Mill-Max 2308-2-00-80-00-00-07-0
7 1 JP1 Header, 3 Pin, 2mm Samtec TMM-103-02-L-S
8 1 R1 Res, 154k 1% 1/16W, 0402 Vishay CRCW0402154KFKEA
9 1 R2 Res, 56.2k 1% 1/16W, 0402 Vishay CRCW040256K2FKED
10 2 R4, R3 Res, 100k 1% 1/16W, 0402 Vishay CRCW0402100KFKED
11 1 R5 Res, 10k 5% 1/16W, 0402 Vishay CRCW040210K0JNED
12 1 U1 IC, Module Linear Technology LTM8023EV
13 4 Standoff, Snap On Keystone 8831
14 1 XJP1 Shunt, 2mm Samtec 2SN-BK-G
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DEMO MANUAL DC1195A
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.
SCHEMATIC DIAGRAM
5
5
4
4
3
3
2
2
1
1
D D
C C
B B
A A
3.3V/2A
ON
OFF
1
3
2
W. GU
*
5V - 36V
PROD
3 10/29/07
REVISION HISTORY
DESCRIPTION DATE APPROVEDECO REV
Customer Notice:
Linear Technology has made a best effort to
design a circuit that meets customer-supplied specifications;
however, it remains the customers 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
Applications Engineering for assistance.
This circuit is proprietary to Linear Technology and supplied
for use with Linear Technology parts.
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DC1195A
Wednesday, January 02, 2008
11
SCH, LTM8023EV, 2A DC/DC STEP-DOWN
MEI 11/29/06
1195A-3.DSN
MODULE
SIZE
SCALE:
CAGE CODE DWG NO REV
SHEET OF
FILENAME:
TITLE
CONTRACT NO.
APPROVALS DATE
DRAWN
CHECKED
APPROVED
ENGINEER
DESIGNER
TECHNOLOGY
1630 McCarthy Blvd.
Milpitas, CA 95035
Phone: (408)432-1900
Fax: (408)434-0507
VOUTVIN
VIN
E4
VOUT
E9
GND
C2
22uF
10V
C1
2.2uF
50V
E5
GND
E8
BIAS
R2 56.2K
1%
R1
154K
1%
E2
GND
R4
100K
1%
G1,G2,G3
B3,B4,C1,C2,C3,C4
GND
A5,A6,A7,B5
E1,E2,E3,E4,
H1,H2,H3
A1,A2,A3,A4,B1,B2,
B6,B7,C5,C6
C7,D1,D2,D3,
D4,D5,D6,D7,
E5,E6,E7,F6
VIN VOUT
U1
LTM8023EV
G5
H5
F7
F5
G6
H6
G7
H7
BIAS
RUN/SS
SHARE
AUX
SYNC
PGOOD
RT
ADJ
E6
SYNC
E3
RUN/SS
C3
0.1uF
+
CIN
22uF
50V
E7
PGOOD
R3
100K
1%
R5
10K
JP1
E1
VIN
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DEMO MANUAL DC1195A
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com
LINEAR TECHNOLOGY CORPORATION 2010
LT 1010 • PRINTED IN USA
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 direc-
tive 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 applica-
tion engineer.
Mailing Address:
Linear Technology
1630 McCarthy Blvd.
Milpitas, CA 95035
Copyright © 2004, Linear Technology Corporation
