1
dc2244afa
DEMO MANUAL DC2244A
DESCRIPTION
LTM8049
Dual SEPIC or Inverting
µModule DC/DC Converter
Demonstration circuit 2244A features the LT M
®
8049, a dual
SEPIC or inverting μModule
®
regulator. The demo circuit
is configured as two stand-alone DC/DC converters with
+12.0V and –12V output voltages from an input voltage
up to 20V. The switching frequencies of both channels
are set at 1MHz on DC2244A. The frequency foldbacks
when the output is 15% below the target regulation point
during a fault or output overload, thus protects the power
switch from damage.
Both channels can be configured as either SEPIC or in-
verting by simply grounding the appropriate output rail,
component change, and/or PCB board cut. The maximum
output current of each channel varies with the input voltage, L, LT, LTC, LTM, Linear Technology and the Linear logo and μModule are registered
trademarks of Linear Technology Corporation. All other trademarks are the property of their
respective owners.
BOARD PHOTO
and is 1A at 12VIN. The two channels can be paralleled
for higher output current with SHARE1, SHARE2 pins tied
together. See the Quick Start Procedure for more informa-
tion on the modification of the board, and paralleling of
two outputs.
The LTM8049 data sheet gives complete description of
the device, operation and application information. The data
sheet must be read in conjunction with this demo manual
prior to working on or modifying demo circuit 2244A.
Design files for this circuit board are available at
http://www.linear.com/demo/DC2244A
2
dc2244afa
DEMO MANUAL DC2244A
QUICK START PROCEDURE
PERFORMANCE SUMMARY
Specifications are at TA = 25°C
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
VIN Input Supply Range 2.8 18 V
FSW Switching Frequency VIN = 12V, IOUT1 = 1A 1 MHz
VOUT1 Output Voltage of Channel 1, SEPIC 11.75 12 12.25 V
IOUT1 Maximum Output Current of Channel 1 VIN = 12V 1 A
VOUT1 (AC) Output Ripple of Channel 1 (Across C5) VIN = 12V, IOUT1 = 0.7A 60 mV
η1Efficiency of Channel 1 VIN = 12V, IOUT1 = 0.7A 82 %
VOUT2 Output Voltage of Channel 2, INVERTING –11.75 –12 –12.25 V
IOUT2 Maximum Output Current of Channel 2 VIN = 12V 1 A
VOUT2 (AC) Output Ripple of Channel 2 (Across C6) VIN = 12V, IOUT2 = 0.7A 20 mV
η2Efficiency of Channel 2 VIN = 12V, IOUT2 = 1A 81.0 %
Demo circuit 2244A is an easy way to evaluate the per-
formance of the LTM8049. Refer to Figure 1 for proper
measurement equipment setup, and follow the proce-
durebelow:
1. Place JP1 and JP2 in EN position.
2. With power off, connect the input power supply to VEMI
and GND. Connect the load to VOUT1P and VOUT1N,
VOUT2P and VOUT2N.
3. Set voltage of the DC power supply at 12V. Turn on the
power at the input.
Note. Make sure that the input voltage does not
exceed20V.
4. Check for the proper output voltage between VOUT1P
and VOUT1N (VOUT1P = 12V). Check for the proper
output voltage between VOUT2P and VOUT2N
(VOUT2N = –12V).
Note. If there is no output, or output voltage value is out
of the spec, temporarily disconnect the load to make
sure that the load is not set too high.
Note. The circuit features frequency foldback to protect
the power switches during a fault or output current
overload. During startup, the frequency foldback also
limits the current the circuit delivers to the load. Refer to
LTM8049 data sheet for more information on maximum
output current and startup current.
5. Once the proper output voltage at each channel is es-
tablished, adjust the load within the operating range and
measure the output voltage regulation, ripple voltage,
efficiency and other parameters.
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 VEMI and GND terminals, VOUT1P and VOUT1N
terminals, or VOUT2P and VOUT2N terminals. See
Figure 2 for proper scope probe technique.
6. An external clock can be added to the SYNC1 terminal
when SYNC function is used. The clock from CLKOUT2
can be used to sync the other boards, and its duty ratio
varies with the internal temperature of the module.
7. The board is set for positive output at channel 1, and
negative output at channel 2. The outputs can be set to
other voltages by changing the feedback resistors (R9 or
R10). To modify the board for two negative outputs, cut
the copper along C5 and short the other terminal of C5 to
ground. Remove resistor R9 and staff the resistor R10 with
proper values. Refer to Figure 3a. To modify the board for
two positive outputs, cut the copper along C6 and short the
other terminal of C6 to ground. Remove resistor R12 and
staff the resistor R11 with proper values. Refer to Figure3b.
8. Two outputs of same voltage can be paralleled to increase
the output current capability. Make sure a 0Ω resistor is
added to R8. To ensure better current sharing, grounds
of the two output caps C5 and C6 must be connected
with short wires.
3
dc2244afa
DEMO MANUAL DC2244A
Figure 1. DC2244A Proper Equipment Setup
QUICK START PROCEDURE
Figure 2. Measuring Input or Output Ripple
V
IN
or V
OUT
GND
4
dc2244afa
DEMO MANUAL DC2244A
QUICK START PROCEDURE
Figure3. Change the Boards to (a) Two Negative Outputs, (b) Two Positive Outputs
(b)
(a)
5
dc2244afa
DEMO MANUAL DC2244A
QUICK START PROCEDURE
Figure4. DC2244A Thermal Performance (12VIN, IOUT1 = IOUT2 = 0.7A, TA = 25°C)
(a) VIN = 12V (b) VIN = 20V
Figure5. DC2244A Efficiency vs Load Current (TA = 25°C)
LOAD CURRENT, CHANNEL 1 (A)
0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
66
68
70
72
74
76
78
80
82
84
EFFICIENCY (%)
DC2244A F05
FSW = 1.5MHz, CHANNEL 1
FSW =1MHz, CHANNEL 1
VIN = 12V
Figure6. Output Noise Spectrum with 0.7A Load Current (VIN = 12V, Short Output Ferrite Beads)
(a) VOUT1 Noise Spectrum, IOUT1 = 0.7A (b) VOUT2 Noise Spectrum, IOUT2 = 0.7A
DC2244A F06a
INTENSITY (dBm)
0
–10
–80
–90
–100
–50
–60
–70
–30
–40
–20
FREQUENCY (MHz)
0 4.5
0.5 1.0 1.5 2.52.0 3.0 3.5 4.0 5.0
OUT1: 12V AT 0.7A
DC2244A F06b
INTENSITY (dBm)
0
–10
–80
–90
–100
–50
–60
–70
–30
–40
–20
FREQUENCY (MHz)
0 4.5
0.5 1.0 1.5 2.52.0 3.0 3.5 4.0 5.0
OUT2: –12V AT 0.7A
6
dc2244afa
DEMO MANUAL DC2244A
PARTS LIST
ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER
Required Circuit Components
1 4 C1, C2, C9, C10 CAP., X7R, 10µF, 25V, 10%, 1206 MURATA, GRM31CR71E106KA12L
2 2 C3, C4 CAP., X7R, 22nF, 25V, 10%, 0603 MURATA, GRM188R71E223KA01D
3 1 C5 CAP, X7R, 22µF, 16V, 10% , 1210 MURATA, GRM32ER71C226KE18L
4 1 C6 CAP, X5R, 47µF, 16V, 10%, 1210 MURATA, GRM32ER61C476KE15K
5 2 C13, C14 CAP, X5R, 10µF, 16V, 10%, 0603 MURATA, GRM188R61C106KAALD
6 2 C7, C8 CAP, X5R, 1µF, 16V, 10%, 0402 MURATA, GRM155R61C105KE01D
7 1 C11 CAP, X7R, 0.1µF, 25V,10%, 0402 MURATA, GRM155R71E104KE14D
8 1 C12 CAP., ALUM, 27µF, 25V SUN ELECT., 25HVH27M
9 2 R1, R3 RES., CHIP., 100k, 1/10W, 1% , 0603 VISHAY, CRCW0603100KFKEA
10 3 R5, R6, R7 RES., CHIP., 80.6k, 1/10W, 1%, 0603 VISHAY, CRCW060380K6FKEA
11 1 R9 RES., CHIP., 130k, 1/10W, 1%, 0603 VISHAY, CRCW0603130KFKEA
12 1 R12 RES., CHIP., 143k, 1/10W, 1%, 0603 VISHAY, CRCW0603143KFKEA
13 2 R13, R14 RES, CHIP., 200k, 1/10W, 1%, 0603 VISHAY, CRCW0603200KFKEA
14 3 FB1, FB2, FB3 Ferrite Bead, 220Ω MPZ2012 TDK Corp. MPZ2012S221AT000
15 1 U1 IC., LTM8049EY BGA LINEAR TECH., LTM8049EY#PBF
Additional Demo Board Circuit Components
1 2 C15, C16 (OPT) CAP, X5R, 1µF, 25V, 10%, 0402 MURATA, GRM155R61E105KA12D
2 2 C17, C18 (OPT) CAP, X5R,0.47µF, 16V, 10%, 0402 TDK Corporation,C1005X5R1C474K050BC
3 0 R2, R4, R8, R10, R11(OPT) RES., OPT, 0603
Hardware for Demo Board Only
1 12 E1-E12 TESTPOINT, TURRET, .094" pbf MILL-MAX, 2501-2-00-80-00-00-07-0
2 2 JP1, JP2 3 PIN 0.079 SINGLE ROW HEADER SULLIN, NRPN031PAEN-RC
3 2 XJP1, XJP2 SHUNT, .079" CENTER WURTH, 608 002 134 21
4 4 (STAND-OFF) STAND-OFF, NYLON 0.25" KEYSTONE, 8831(SNAP ON)
–15
–10
–5
0
5
10
15
20
25
30
35
40
45
50
0 100 200 300 400 500 600 700 800 900 1000
DC2244A F07
AMPLITUDE (dBµV/m)
FREQUENCY (MHz)
DATA
CLASS 5 PEAK
QUICK START PROCEDURE
Figure 7. Radiated EMI CISPR25- Class 5 Peak Limit (Vertical Polarization) with 0.7A Load Current. (VIN = 14V)
7
dc2244afa
DEMO MANUAL DC2244A
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 representa-
tion 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
NOTE: UNLESS OTHERWISE SPECIFIED
1. ALL RESISTORS AND CAPACITORS ARE 0603.
+12V
-12V
2.8V - 18V
*
*
*
SEE DEMO MANUAL FOR MAXIMUM IOUT.
VIN
VIN
SIZE
DATE:
IC NO. REV.
SHEET OF
TITLE:
TECHNOLOGY Fax: (408)434-0507
Milpitas, CA 95035
Phone: (408)432-1900
1630 McCarthy Blvd.
LTC Confidential-For Customer Use Only
CUSTOMER NOTICE
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.
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SCHEMATIC
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
www.linear.com
4
DEMO CIRCUIT 2244A
Monday, October 03, 2016 11
DUAL SEPIC OR INVERTING
N/A
LTM8049EY
µMODULE DC/DC CONVERTER
SIZE
DATE:
IC NO. REV.
SHEET OF
TITLE:
TECHNOLOGY Fax: (408)434-0507
Milpitas, CA 95035
Phone: (408)432-1900
1630 McCarthy Blvd.
LTC Confidential-For Customer Use Only
CUSTOMER NOTICE
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.
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SCHEMATIC
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
www.linear.com
4
DEMO CIRCUIT 2244A
Monday, October 03, 2016 11
DUAL SEPIC OR INVERTING
N/A
LTM8049EY
µMODULE DC/DC CONVERTER
SIZE
DATE:
IC NO. REV.
SHEET OF
TITLE:
TECHNOLOGY Fax: (408)434-0507
Milpitas, CA 95035
Phone: (408)432-1900
1630 McCarthy Blvd.
LTC Confidential-For Customer Use Only
CUSTOMER NOTICE
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.
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SCHEMATIC
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
www.linear.com
4
DEMO CIRCUIT 2244A
Monday, October 03, 2016 11
DUAL SEPIC OR INVERTING
N/A
LTM8049EY
µMODULE DC/DC CONVERTER
FB1
220
R10
OPT
R3
100K
C18
0402
OPT
FB3 220
C17
0402
OPT
R12
143K
E2
PG2
E4
RUN1
0.1uF
25V
C11
0402
LTM8049EY
U1
GND
F5
GND
F6
GND
F7
VOUT2N G1
VOUT2N G2
GND
G3
GND
G4
GND
G5
CLKOUT2
G6
RT2
G7
VOUT2N H1
VOUT2N H2
GND
H3
GND
H4
GND
H5
PG2 H6
SYNC2
H7
FBX2 J1
VOUT2N J2
GND
J3
GND
J4
GND
J5
GND
J6
SS2
J7
VOUT2P K1
VOUT2P K2
GND
K3
GND
K4
GND
K5
GND
K6
RUN2
K7
VOUT2P L1
VOUT2P L2
GND
L3
GND
L4
VIN2 L5
VIN3 L6
VIN4 L7
GND
C4
GND
C5
GND
C6
SS1
C7
VOUT1N D1
VOUT1N D2
GND
D3
GND
D4
GND
D5
PG1 D6
SYNC1
D7
VOUT1N E1
VOUT1N E2
GND
E3
GND
E4
GND
E5
CLKOUT1
E6
RT1
E7
GND
F1
GND
F2
SHARE1
F3
SHARE2
F4
VOUT1P A1
VOUT1P A2
GND
A3
GND
A4
VIN1 A5
VIN1 A6
VIN1 A7
VOUT1P B1
VOUT1P B2
GND
B3
GND
B4
GND
B5
GND
B6
RUN1
B7
FBX1 C1
VOUT1N C2
GND
C3
R2
OPT
E5
RUN2
E3
GND
22nF
25V
C4
OPT
C16
0402
OPT
C15
0402
R14
200K
FB2 220
R5
80.6k
47uF
C6
16V
1210
1uF
16V
C8
0402
R1
100K
JP1
EN
DIS
1
3
2
10uF
C14
16V
10uF
C13
16V
10uF
25V
C1
1206
R11
OPT
10uF
25V
C2
1206
JP2
EN
DIS
1
3
2
E11 VOUT2P
E10
VOUT1N
R4
OPT
R8
OPT
R6
80.6k
+
27uF
25V
C12
25HVH27M
10uF
25V
C9
1206
R9
130K
22nF
25V
C3
E8 PG1
E6
SYNC1
22uF
C5
16V
1210
E12
VOUT2N
R13
200K
R7
80.6k
E7
CLKOUT2
E9
VOUT1P
1uF
16V
C7
0402
E1
VEMI
10uF
25V
C10
1206
8
dc2244afa
DEMO MANUAL DC2244A
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com
© LINEAR TECHNOLOGY CORPORATION 2016
LT 1016 REV A • 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
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
