DEMO MANUAL DC1144A
LT3580EDD Boost/
Inverting Regulator
DESCRIPTION
Demonstration circuits 1144A-A and 1144A-B feature the
LT
®
3580EDD
in Boost/Inverting Regulator configurations.
The demo circuits demonstrate small size and low com-
ponent count. The boost is designed to convert a 3V to
10V source to 12V at 300mA while the inverter converts
a 5V to 12V source to –12V at 350mA. Both converters
use only one feedback resistor to set the output voltage.
The LT3580 operates with inputs as high as 32V but in
these demo boards the input is limited by the voltage
rating of the input capacitors and the magnitude of the
boost output. In a boost converter the input needs to be
less than the output.
Care must be taken when operating the LT3580 at high
input voltages as the junction temperature increases due
to higher internal dissipation. Higher switching frequencies
also increase the internal dissipation.
The LT3580 gets powered from the main input in both,
DC1144A-A and DC1144A-B, but there is an option for a
linear regulator built into the board that will allow the IC
to be powered from a lower voltage. If this option is used,
just cut the trace as shown in Figure 6 and install the op-
tional emitter follower regulator on the back of the board.
The DC1144A-B can easily be configured into a SEPIC
converter, just switch the positions of L2 and D2 as shown
in Figure 6.
The LT3580 includes many other features such as Synchro-
nization to external clock, User Configurable Undervoltage
Lockout, Soft-start, Frequency Foldback, and it is easily
configured as boost or inverting converter.
These circuits are intended for space-conscious applica-
tions such as Local Bias Supplies, TFT-LCD Bias Supplies,
GPS Receivers, VFD Bias Supplies and DSL Modems.
Design files for this circuit board are available at
http://www.linear.com/demo/DC1144A
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
Performance Summary DC11144A-A
SYMBOL
V
IN
V
OUT
Ripple
Efficiency
Switching Frequency
PARAMETER
Input Supply Range
Output Voltage Range
Specifications are at T
A
= 25°C
CONDITIONS
V
IN
= 3V, I
LOAD
= 300mA
V
IN
= 3.6V, I
LOAD
= 300mA
V
IN
= 4.2V, I
LOAD
= 350mA
MIN
3
11.64
12
40
88
1
TYP
MAX
10
12.36
UNITS
V
V
mV
%
MHz
Performance Summary DC11144A-B
SYMBOL
V
IN
V
OUT
Ripple
Efficiency
Switching Frequency
PARAMETER
Input Supply Range
Output Voltage Range
V
IN
= 5V, I
LOAD
= 350mA
V
IN
= 5V, I
LOAD
= 350mA
V
IN
= 5V, I
LOAD
= 350mA
CONDITIONS
MIN
5
–11.64
–12
10
80
2
TYP
MAX
12
–12.36
UNITS
V
V
mV
%
MHz
dc1144af
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DEMO MANUAL DC1144A
QUICK START PROCEDURE
Demonstration circuit 1144A is easy to set up to evaluate the
performance of the LT3580EDD. Refer to
Error! Reference
source not found.
and Figure 2 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
Error! Reference source
not found.
for proper scope probe technique.
1. Place jumpers in the following positions:
JP1 ON
2. With power off, connect the input power supply to V
IN
and GND.
3. Turn on the power at the input.
4. 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.
5. 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. Proper Measurement Equipment for DC1144A-A
2
dc1144af
DEMO MANUAL DC1144A
QUICK START PROCEDURE
Figure 2. Proper Measurement Equipment for DC1144A-B
Figure 3. Measurement Input and Output Ripple
VIN
GND
dc1144af
3
DEMO MANUAL DC1144A
QUICK START PROCEDURE
90
80
EFFICIENCY (%)
EFFICIENCY (%)
50 100 150 200 250 300 350 400 450 500
OUTPUT CURRENT (mA)
1144A F04
80
70
70
60
50
40
30
60
50
40
0
30
0
40
60 120 160 200 240 300 340 400
OUTPUT CURRENT (mA)
1144A F05
Figure 4. Boost Converter Efficiency at 4.2V
IN
Figure 5. Inverting Regulator Efficiency at 5V
IN
Figure 6. Optional Modifications to Convert DC1144A-B to ZEPIC Converter and/or Use Separate Regulator to Bias IC
4
dc1144af
DEMO MANUAL DC1144A
PARTS LIST
QTY
1
1
1
1
1
1
1
1
1
1
1
0
1
0
0
6
1
1
0
2
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
U1
C6
U1
C3 (OPT)
C5
C8 (OPT)
D3 (OPT)
TP1-TP6
JP1
XJP
Q2 (OPT)
R4, R8
R9 (OPT)
C1
C2
C4
C6
C7
C8
D2
L1
L2
R2
R5
R6
CAP., X5R,1μF, 25V,10%, 0805
CAP., X5R, 4.7μF, 16V, 20% 1206
CAP., X5R, 10μF, 25V, 20% 1206
CAP., X5R, 0.1μF, 16V, 10% 0402
CAP., X7R, 2200pF, 16V, 10% 0402
CAP., NPO, 100pF, 25, 10%, 0402
DIODE, SCHOTTKY RECTIFIER 2A, POWER D123
INDUCTOR, 8.2μH
INDUCTOR, 15μH
RES., CHIP, 143k, 1/6W, 1% 0402
RES., CHIP, 20k, 1/16W, 1% 0402
RES., CHIP, 42.2k, 1/6W, 1% 0402
FAB, PRINTED CIRCUIT BOARD
LT3580EDD, 8-LEAD PLASTIC DFN (3X3)
AVX, 08053D105KAT
TAIYOYUDEN, EMK316BJ475ML
TAIYOYUDEN, TMK316ABJ106ML-T
AVX, 0402YC104KAT2A
MURATA, GRM155R71C222KA01D
AVX, 04023A101KAT2A
DIODES INC., DFLS130L-7
COOPER BUSSMANN, SD25-8R2-R
COOPER BUSSMANN, SD14-150-R
VISHAY, CRCW0402143KFKED
VISHAY, CRCW040220K0FKED
VISHAY, CRCW040242K2FKED
DEMO CIRCUIT 1144A-B
LINEAR TECH., LT3580EDD#PBF
RES., CHIP, 100k, 1/10W, 1% 0805
VISHAY, CRCW0805100KFKEA
TESTPOINT, TURRET
0.079 SINGLE ROW HEADER, 3 PIN
SHUNT
MILL MAX 2501-2-00-80-00-00-07-0
SAMTEC, TMM103-02-L-S
SAMTEC, 2SN-BK-G
REFERENCE
C2
C4
C7
D1
L1
R2
R5
R6
PART DESCRIPTION
CAP., X5R, 4.7μF, 16V, 20% 1206
CAP., X5R, 10μF, 25V, 20% 1206
CAP., X7R, 1000pF, 16V, 10% 0402
DIODE, SCHOTTKY RECTIFIER 2A, POWER D123
INDUCTOR, 6.8μH
RES., CHIP, 130k, 1/6W, 1% 0402
RES., CHIP, 20k, 1/16W, 1% 0402
RES., CHIP, 84.5k, 1/6W, 1% 0402
FAB, PRINTED CIRCUIT BOARD
CAP., X7R, 0.1μF, 16V, 10% 0402
LT3580EDD, 8-LEAD PLASTIC DFN (3X3)
CAP., 0402
CAP., X7R, 0.1μF, 16V, 10% 0603
CAP., 0402
AVX, 0603YC104KAT2A
MANUFACTURER/PART NUMBER
TAIYOYUDEN, EMK316BJ475ML
TAIYOYUDEN, TMK316ABJ106ML-T
MURATA, GRM155R71C102KA01D
DIODES INC., DFLS220L-7
SUMIDA, CDRH5D16NP-6R8NC
VISHAY, CRCW0402133KFKED
VISHAY, CRCW040220K0FKED
VISHAY, CRCW040284K5FKED
DEMO CIRCUIT 1144A-A
AVX, 0402YC104KAT2A
LINEAR TECH., LT3580EDD#PBF
Required Circuit Components for Boost Converter
Additional Demo Board Circuit Components
Required Circuit Components for Inverting Regulator
dc1144af
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