Linear Technology DC1533A Quick setup guide

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DEMO MANUAL DC1533A
DESCRIPTION
LTM8045
Inverting/SEPIC µModule Converter
with Up to 700mA Output
DemocircuitDC1533AfeaturestheLTM
®
8045,aninverting/
SEPIC Module converter deliveringup to 700mAof output
current. DC1533A is configured as an inverting converter,
but can be easily changed to a SEPIC configuration for
non-inverting step-up or step-down functionality. The
user adjustable features of the LTM8045 such as output
voltage, switching frequency, soft-start period and under-
voltage lockout can be changed on DC1533A simply by 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.
PERFORMANCE SUMMARY
BOARD PHOTO
modifying or installing the appropriate resistors or capaci-
tor. The LTM8045 data sheet must be read in conjunction
with this demo manual to properly use or modify demo
circuit DC1533A.
Design files for this circuit board are available at
http://www.linear.com/demo
(TA= 25°C)
PARAMETER CONDITIONS MIN TYP MAX UNITS
Minimum Input Voltage, VIN 2.8 V
Maximum Input Voltage, VIN 18 V
Regulator Output Voltage, VOUT–R2 = 60.4k –4.83 –5.19 V
Maximum Output Current, IOUT–VIN = 5V
VIN = 12V
430
580
mA
mA
Efficiency VIN = 5V, IOUT–= 400mA 80 %
Switching Frequency R1 = 130k 700 kHz

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DEMO MANUAL DC1533A
QUICK START PROCEDURE
Figure 1. Proper Measurement Equipment Setup
Demo circuit DC1533A is an easy way to evaluate the
performance of the LTM8045. Refer to Figure 1 for the
proper measurement equipment setup and Figure 2 for
the maximum output current versus input voltage, then
follow the procedure below:
NOTE: Do not hot-plug the VIN terminal at high input volt-
ages. Hot-plugging a power supply through wire leads
to the demonstration circuit can cause the voltage on
the extremely low ESR ceramic input capacitor to ring to
twice its DC value. In order to protect the LTM8045, an
aluminum electrolytic capacitor with higher ESR is placed
at the input terminals. This may protect against some, but
not all, input transients due to a hot-plugged power supply.
See Application Note 88 for more details.
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 in the ON position.
2. Connect the power supply (with power off), load, and
meters as shown in Figure 1.
3. After all connections are made, turn on the input power
and verify that the output voltage is –5V.
NOTE: If the output voltage is too low, temporarily discon-
nect the load to make sure that the load is not set too high.
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.
NOTE: See the section that follows for instructions to
convert DC1533A to a 5VOUT SEPIC with a positive VOUT.

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DEMO MANUAL DC1533A
QUICK START PROCEDURE
INPUT VOLTAGE (V)
300
600
550
650
350
400
500
450
DC1533A F02
OUTPUT CURRENT (mA)
28104 6 12 14 16 18
Figure 2. Maximum Output Current vs Input Voltage for VOUT = –5V
Figure 3. Proper Scope Probe Technique
DC1533A F03
GNDVIN OR VOUT

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DEMO MANUAL DC1533A
Instructions to Convert DC1533A to a 5VOUT SEPIC with a Positive VOUT
1. Start with DC1533A. Disconnect all supplies and loads.
2. Remove R2 and install R3 = 45.3k as shown in Figure 4. R3 MUST BE PRESENT BEFORE OPERATION OTHERWISE
THE LTM8045 MAY BE DAMAGED.
Figure 4
3. Make three cuts on the top copper to separate the terminal labeled GND from the ground plane, as shown in
Figure 5. The terminal labeled GND is now VOUT+.
Figure 5

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DEMO MANUAL DC1533A
4. Solder the exposed copper together with braid to connect the terminal labeled VOUT–to the ground plane, as shown
in Figure 6. The terminal labeled VOUT–is now GND.
5. Change C2 to 100µF 6.3V 1206 or 1210. Change R1 to 115k to optimize the switching frequency.
Figure 6

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DEMO MANUAL DC1533A
PARTS LIST
ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER
Required Circuit Components
1 1 C1 CAP., X7R, 4.7µF, 25V, 10%, 1206 NIC, NMC1206X7R475K25TRPLPF
2 1 C2 CAP., X5R, 22µF, 16V, 10%, 1206 AVX, 1206YD226KAT2A
3 1 C3 CAP., X7R, 10nF, 16V, 10%, 0603 AVX, 0603YC103KAT2A
4 1 R1 RES., CHIP, 130k, 1% ,0603 VIAHSY, CRCW0603130KFKEA
5 1 R2 RES., CHIP, 60.4k, 1% , 0603 VISHAY, CRCW060360K4FKED
6 1 U1 I.C., LTM8045EY#PBF, BGA LINEAR TECH., LTM8045EY#PBF
Optional Demo Circuit Components
1 0 CIN1 CAP., SMT, 47µF, 50V SUNCON, 50CE47BS
2 0 C4 CAP., X7R, 47µF, 16V, 20%, 1210
3 0 C5 CAP., X7R, 4.7µF, 25V, 10%, 1206
4 0 L1, L2 IND., 1.0µH, 20%,1812 MURATA, LQH43CN1R0M03
5 0 R3 RES., 0603
6 0 R4 RES., CHIP, 0, 0603 VISHAY, CRCW06030000Z0EA
7 0 R5, R6 RES., CHIP, 0603
Hardware
1 6 E1-E6 TESTPOINT, TURRET, .095" MILL-MAX, 2501-2-00-80-00-00-07-0
2 1 JP1 2MM SINGLE ROW HEADER, 3 PIN SAMTEC, TMM-103-02-L-S
3 1 XJP1 SHUNT, .079" CENTER SAMTEC, 2SN-BK-G
4 4 (STAND-OFF) STAND-OFF, NYLON 0.375" TALL KEYSTONE, 8832(SNAP ON)

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DEMO MANUAL DC1533A
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
R4
0 Ohm
R2
60.4k
E4
SYNC
SEE FIGURE 2 FOR
*
JP1 12
3
VOUT-
U1
LTM8045EY
VIN H5
VIN H4
VIN G5
VIN G4
SYNC
E1
RUN
G3
GND
C1
GND
C2
GND
C3
GND
C4
GND
C5
GND
D4
GND
D5
GND H2
GND
E2
GND
E3
GND
E4
GND
E5
GND
F2
GND
F3
GND
F4
GND
G2
GND
H1
GND
D1
VOUT+ B1 VOUT+ A2 VOUT+ A1
SS
F1
RT
G1
GND
D2
GND
D3
GND
F5
GND H3
VOUT+ B2
FB A3
VOUT- A4 VOUT- A5 VOUT- B4 VOUT- B5
GND
B3
E6
GND
+
CIN1 47uF
50V
L1
1.0uH C4
47uF 16V
1210
LQH43CN1R0M03
C3
10nF
0603
6.3mm DIA
RUN CONTROL
R1
130k
THE MAXIMUM OUTPUT CURRENT
R3
OPT
VOUT-
VERSUS VIN.
E5 -5V
700kHz
E1
VIN
LQH43CN1R0M03
VOUT-
E2 GND
OFF
ON
C2
22uF 16V
OPT
*
OPT
E3
GND
NOTE: UNLESS OTHERWISE SPECIFIED 1. ALL RESISTORS ARE 0603 1%. 2. ALL CAPACITORS ARE 1206.
L2
1.0uH
C5
4.7uF
25V
OPT
OPT
C1
4.7uF
25V
R5
OPT
R6
OPT
2.8V - 18V

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DEMO MANUAL DC1533A
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
[phone] ●FAX: [phone] ●www.linear.com
© LINEAR TECHNOLOGY CORPORATION 2013
LT 0113 • 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
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