Linear Technology DC1734A Quick setup guide

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DEMO MANUAL DC1734A
DESCRIPTION
LT8582
Dual 3A Boost/Inverting/SEPIC
DC/DC Converter
Demonstration circuit 1734A features the dual channel
LT
®
8582 in boost and inverting regulator configurations.
The circuit is designed to convert a 5V to 10V input source
to 12V at 900mA and –12V at 590mA as shown in Table 1.
Table 1. Maximum Guaranteed Output Currents
VIN (V) MAX ILOAD1 (mA) MAX ILOAD2 (mA)
4.5 775 540
5.0 900 590
5.5 1000 625
To limit the temperature rise of the chip to 40°C, on the
demo board with no air flow, the maximum combined
output power is 15W. Additional input bulk capacitance
may be needed, subject to source impedance.
DC1734A is designed tosurvive output short circuit events.
On the positive channel an external disconnect MOSFET
protects the boost converter. The negative channel is
based on dual inductor inverting topology and does not
need the external MOSFET as it is inherently output short
protected. The circuit board includes an option to install
the external disconnect MOSFET at the input side of the
positive channel. To use it, remove Q1 and R1 from the
top of the circuit board and install them on the back, in
the location of Q2 and R2. Then, place a jumper from Q1’s
source to drain and cut the top copper as shown in Figure 6.
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.
PERFORMANCE SUMMARY
To change the topology of channel 1 from boost to invert-
ing: Replace D1 with a capacitor similar to C12, replace
C2 with a diode similar to D3, placing the diode so that
its cathode is connected to ground, and replace R16 with
an inductor similar to L3.
To changethe topology ofchannel 2 frominverting toboost:
Replace C12 with a diode similar to D1, placing the diode so
that its anodeis connected toL2, replaceD3 with acapacitor
similar to C2, and replace L3 with a jumper resistor similar
to R16. However, this configuration will not be output short
protected since it lacks the external disconnect MOSFET.
Each channel of the LT8582 includes a 42V master and slave
power switchcombinationwith3Atotalcurrentandcaneasily
beconfiguredasaboost,SEPIC,invertingorflybackconverter.
The LT8582 has a 2.5V to 22V operating input range, UVLO,
soft-start,programmable switchingfrequencyand manyother
features. The LT8582 data sheet gives a complete description
of the part, its operation and application information. The
data sheet must be read in conjunction with this quick start
guide for working on or modifying the demo circuit 1734A.
Design files for this circuit board are available at
http://www.linear.com/demo
(TA= 25°C)
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
VIN Input Supply Range 510V
VOUT1 Channel 1 Output Voltage Accuracy VIN = 5V to 10V, ILOAD = 900mA 11.6 12 12.4 V
Channel 1 Output Voltage Ripple VIN = 5V, ILOAD = 900mA 60 mVPP
Channel 1 Efficiency VIN = 5V, ILOAD = 900mA 86 %
Channel 1 Efficiency VIN = 10V, ILOAD = 900mA 92 %
VOUT2 Channel 2 Output Voltage Accuracy VIN = 5V to 10V, ILOAD = 590mA –11.5 –12 –12.3 V
Channel 2 Output Voltage Ripple VIN = 5V, ILOAD = 590mA 56 mVPP
Channel 2 Efficiency VIN = 5V, ILOAD = 590mA 83 %
Channel 2 Efficiency VIN = 10V, ILOAD = 590mA 85 %
fSSwitching Frequency 1 MHz
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DEMO MANUAL DC1734A
Figure 1. Proper Measurement Equipment Setup
Demonstration circuit DC1734A is easy to set up to evalu-
ate the performance of the LT8582. Refer to Figure 1 for
proper measurement equipment set-up and follow the
procedure below.
To measure voltage ripple, care must be taken to avoid a
long ground lead on the oscilloscope probe. Remove the
oscilloscope probe end cap and ground lead and set the
bandwidth limit on the oscilloscope. Measure the input
voltage ripple by touching the probe tip and ground directly
across VIN and GND terminals. See Figure 2 for proper
input voltage ripple measurement technique. Measure the
positive output voltage ripple by touching the probe tip
directly across output capacitor C16 terminals, connect-
ing the probe ground terminal to the board’s GND plane.
Measure the negative output voltage ripple by touching the
probe tip directly across output capacitor C9, connecting
the probe ground terminal to the board’s GND plane. See
Figure 3 for proper output voltage ripple measurement
technique.
1. Place the on board jumpers in the following positions:
To activate boost converter: JP1 ON
To activate inverting converter: JP2 ON
2. With power off, connect the input power supply to VIN
and GND. Apply 7.5V to the input (source must have
greater than 10A capability).
3. Check for the proper output voltages.
NOTE. If there is no output, temporarily disconnect the
load to make sure that the load is not set too high.
4. Once the proper output voltage is established, adjust
the load and the input voltage within the operating
range and observe the output voltage regulation, ripple
voltage, efficiency and other parameters. The efficiency
graphs of the two channels are provided in Figure 4
and Figure 5.
QUICK START PROCEDURE
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DEMO MANUAL DC1734A
QUICK START PROCEDURE
Figure 2. Proper Input Voltage Ripple Measurement Technique
Figure 3. Proper Output Voltage Ripple Measurement Technique
VIN GND
OSCILLOSCOPE
PROBE
OUTPUT
CAP.
OSCILLOSCOPE
PROBE
SOLDER A SMALL
PIECE OF SOLID WIRE
BOARD GND
PLANE
SOLDER
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DEMO MANUAL DC1734A
QUICK START PROCEDURE
Figure 4. Channel 1 Boost Regulator Efficiency at VIN = 5V
Figure 5. Channel 2 Inverting Regulator Efficiency at VIN = 5V
LOAD CURRENT (A)
0
0
10
EFFICIENCY (%)
70
80
90
50
60
20
30
40
100
0.7 0.8 0.90.1 0.2 0.3 0.4 0.5
dc1734a F04
0.6
LOAD CURRENT (A)
0
0
10
EFFICIENCY (%)
70
80
90
50
60
20
30
40
100
0.5 0.60.1 0.2 0.3 0.4
dc1734a F05
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DEMO MANUAL DC1734A
SHORT Q1’s SOURCE AND
DRAIN PADS HERE
CUT COPPER
HERE
Figure 6. Using Channel 1 Input Disconnect Option (See Text)
BOARD MODIFICATIONS
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DEMO MANUAL DC1734A
PARTS LIST
ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER
Required Circuit Components
1 3 C1, C2 CAP., X5R, 10μF, 16V, 20% 1206 AVX, 1206YD106MAT2A
2 1 C9, C16 CAP., X5R, 22μF, 16V, 20% 1206 TAIYO YUDEN, EMK316BJ226ML-T
3 2 C11, C17 CAP., X5R, 4.7μF, 16V, 20% 1206 TAIYO YUDEN, EMK316BJ475ML-T
4 2 C4, C8 CAP., X7R, 2.2nF, 50V, 10%, 0402 AVX, 04025C222KAT2A
5 2 C5, C10 CAP., NPO, 100pF, 16V, 10%, 0402 AVX, 0402YA101KAT2A
6 2 C6, C7 CAP., X7R, 0.1μF, 16V, 10% 0402 TDK, C1005X7R1C104K
7 1 C12 CAP., X7R, 2.2μF, 25V, 10%, 0805 MURATA, GRM21BR71E225KA73L
8 1 D1 RECTIFIER, DFLS220L, PowerDI-123 DIODES/ZETEX, DFLS220L-7
9 1 D3 RECTIFIER, DFLS130L, PowerDI-123 DIODES/ZETEX, DFLS130L-7
10 1 L1 INDUCTOR, 4.7μH VISHAY, IHLP2525CZER4R7M11
11 1 L2 INDUCTOR, 10μH VISHAY, IHLP2525CZER100M11
12 1 L3 INDUCTOR, 10μH VISHAY, IHLP2020BZER100M11
13 1 Q1 P-CH MOSFET, FDMC510P, POWER-33 FAIRCHILD, FDMC510P
14 1 R1 RES., CHIP, 6.04k, 1/16W, 1% 0402 VISHAY, CRCW04026K04FKED
15 1 R3 RES., CHIP,130k, 1/10W, 1%, 0603 NIC, NRC06F1303TRF
16 2 R4, R11 RES., CHIP, 232k, 1/8W, 1%, 0805 VISHAY, CRCW0805232KFKEA
17 1 R5 RES., CHIP, 8.06k, 1/16W, 1% 0402 VISHAY, CRCW04028K06FKED
18 2 R8, R10 RES., CHIP, 80.6k, 1/16W, 1% 0402 VISHAY, CRCW040280K6FKED
19 3 R6, R9, R13 RES., CHIP, 100k, 1/16W, 5% 0402 NIC, NRC04J104TRF
20 1 R12 RES., CHIP, 16.9k, 1/16W, 1% 0402 VISHAY, CRCW040216K9FKED
21 1 R15 RES., CHIP,143k, 1/10W, 1%, 0603 NIC, NRC06F1433TRF
22 1 R16 RES., CHIP, 0Ω, 1/4W, 1206 NIC, NRC12ZOTR
23 1 U1 IC., LT8582EDKD, DFN-24(7MMX4MM) LINEAR TECH., LT8582EDKD
Additional Demo Board Circuit Components
1 0 C3, C14 CAP., 0603, OPTION
2 0 C13 CAP., 1206, OPTION
3 0 C15 CAP., SMD 8X10.5 & THRU HOLE 8X9.5, OPTION
4 0 D2 DIODE, SOD-323, OPTION
5 0 Q2 MOSFET, POWER-33, OPTION
6 0 R2 RES., CHIP, 0402, OPTION
7 0 R7, R14 RES., CHIP, 0805, OPTION
Hardware for Demo Board Only
1 9 E1-E9 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 SAMTEC, TMM103-02-L-S
3 2 XJP1, XJP2 SHUNT, .079" CENTER SAMTEC, 2SN-BK-G
4 4 (STAND-OFF) STAND-OFF, NYLON 0.25" KEYSTONE, 8831(SNAP ON)
5 1 FAB, PRINTED CIRCUIT BOARD DEMO CIRCUIT 1734A
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DEMO MANUAL DC1734A
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
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DEMO MANUAL DC1734A
LinearTechnology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
[phone] ●FAX: [phone] ●www.linear.com
© LINEAR TECHNOLOGY CORPORATION 2011
LT 1111 • 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
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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
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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:
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1630 McCarthy Blvd.
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Copyright © 2004, Linear Technology Corporation
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