DEMO MANUAL DC2297A
LT8570, LT8570-1
Boost/SEPIC/Inverting Regulator
DESCRIPTION
Demonstration circuits 2297A-A and 2297A-B feature the
LT
®
8570
and LT8570-1 in a boost configuration. These
demo circuits demonstrate small size and low component
count. Both converters are designed to convert a 5V to
10V source to 12V. Refer to Figures 3 and 4 for maximum
load current at different input voltage levels.
Both converters use only one feedback resistor to set the
output voltage.
The LT8570 can operate with inputs as high as 40V but
in these demo circuits, the input is limited by the voltage
rating of the input capacitors, and the magnitude of the
output voltage.
The LT8570 and LT8570-1 include many other features
such as synchronization to external clock, user configurable
undervoltage lockout, soft-start, frequency foldback, and
other features that are easily configured as Boost, SEPIC
or Inverting Converters.
The data sheet gives a complete description of the device,
operation and application information. The data sheet must
be read in conjunction with this demo manual for DC2297A.
Design files for this circuit board are available at
http://www.linear.com/demo/DC2297A
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
SYMBOL
DC2297A-A
V
IN
V
OUT
RIPPLE
EFFICIENCY
SWITCHING FREQUENCY
DC2297A-B
V
IN
V
OUT
RIPPLE
EFFICIENCY
SWITCHING FREQUENCY
Input Supply Range
Output Voltage
Input Supply Range
Output Voltage
PARAMETER
Specifications are at T
A
= 25°C
CONDITIONS
MIN
5
V
IN
= 5V, I
LOAD
= 125mA
V
IN
= 5V, I
LOAD
= 125mA
V
IN
= 5V, I
LOAD
= 125mA
11.64
12
25
86
1.5
5
V
IN
= 5V, I
LOAD
= 60mA
V
IN
= 5V, I
LOAD
= 60mA
V
IN
= 5V, I
LOAD
= 60mA
11.64
12
5
86
1.5
10
12.36
TYP
MAX
10
12.36
UNITS
V
V
mV
%
MHz
V
V
mV
%
MHz
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DEMO MANUAL DC2297A
QUICK START PROCEDURE
Demo circuit 2297A is easy to set up to evaluate the per-
formance of the LT8570 and LT8570-1. Refer to Figure 1
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 2 for proper scope
probe technique.
1. With power off, connect the input power supply to VIN
and GND.
2. Turn on the power at the input.
NOTE: Make sure that the input voltage does not
exceed 10V.
3. Check for the proper output voltage.
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 voltages are established, adjust
the load within the operating range and observe the
output voltage regulation, ripple voltage, efficiency and
other parameters.
–
–
+
I
IN
+
–
+
V
IN
POWER
SUPPLY
–
+
V
OUT
–
LOAD
+
–
+
I
OUT
Figure 1. Proper Measurement Equipment Setup
Figure 2. Measuring Input or Output Ripple
VIN
GND
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DEMO MANUAL DC2297A
PARTS LIST
ITEM
QTY
REFERENCE
PART DESCRIPTION
MANUFACTURER/PART NUMBER
DC2297A-A
Required Circuit Components for Boost Regulator
1
2
3
4
5
6
7
8
9
10
11
12
13
1
2
1
DC2297A-B
Required Circuit Components for Boost Regulator
1
2
3
4
5
6
7
8
9
10
11
12
13
1
2
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
6
C1
C2
C3
C4
C6
D1
L1
R2
R3
R5
R6
R7
U1
C5
R4
E–E6
CAP., CER., 4.7µF, X7R, 16V, 10%, 0805
CAP., CER., 0.1µF, X7R, 16V, 10%, 0402
CAP., CER., 2.2nF, X7R, 16V, 10%, 0402
CAP., CER., 47pF, C0G, 25V, 5%, 0402
CAP., CER., 2.2µF, X7R, 16V, 10%, 0805
DIODE, SCHOTTKY, 30V, 1A, DI123
IND., 68µH
RES., 11.3k, 1/8W, 1%, 0805
RES., 10k, 1/8W, 1%, 0805
RES., 56.2k, 1/10W, 1%, 0603
RES., 6.04k, 1/10W, 1%, 0603
RES., 130k, 1/10W, 1%, 0603
I.C., LT8570EDD-1, 8DFN
CAP., CER., 0.1µF, X7R, 16V, 10%, 0603
RES., 100k, 1/8W, 1%, 0805
TEST POINT, TURRET, 0.094" MTG HOLE
MURATA, GRM21BR71C475KA73L
MURATA, GRM155R71C104KA88D
AVX, 0402YC222KAT2A
AVX, 04023A470JAT2A
MURATA, GRM21BR71C225KA12L
DIODES INC., DFLS130-7
U ELEKTRONIK, 744 042 680
VISHAY, CRCW080511K3FKEA
VISHAY, CRCW080510K0FKEA
VISHAY, CRCW060356K2FKEA
NIC, NRC06F6041TRF
VISHAY, CRCW0603130KFKEA
LINEAR TECH., LT8570EDD-1#PBF
TDK, C1608X7R1C104K
VISHAY, CRCW0805100KFKEA
MILL-MAX, 2501-2-00-80-00-00-07-0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
6
C1
C2
C3
C4
C6
D1
L1
R2
R3
R5
R6
R7
U1
C5
R4
E1–E6
CAP., CER., 4.7µF, X7R, 16V, 10%, 0805
CAP., CER., 0.1µF, X7R, 16V, 10%, 0402
CAP., CER., 2.2nF, X7R, 16V, 10%, 0402
CAP., CER., 47pF, C0G, 25V, 5%, 0402
CAP., CER., 4.7µF, X7R, 16V, 10%, 0805
DIODE, SCHOTTKY, 30V, 1A, DI123
IND., 33µH
RES., 11.3k, 1/8W, 1%, 0805
RES., 10k, 1/8W, 1%, 0805
RES., 56.2k, 1/10W, 1%, 0603
RES., 6.04k, 1/10W, 1%, 0603
RES., 130k, 1/10W, 1%, 0603
I.C., LT8570EDD, 8DFN
CAP., CER., 0.1µF, X7R, 16V, 10%, 0603
RES., 100k, 1/8W, 1%, 0805
TEST POINT, TURRET, 0.094" MTG HOLE
MURATA, GRM21BR71C475KA73L
MURATA, GRM155R71C104KA88D
AVX, 0402YC222KAT2A
AVX, 04023A470JAT2A
MURATA, GRM21BR71C475KA73L
DIODES INC., DFLS130-7
WÜRTH ELEKTRONIK, 744 042 330
VISHAY, CRCW080511K3FKEA
VISHAY, CRCW080510K0FKEA
VISHAY, CRCW060356K2FKEA
NIC, NRC06F6041TRF
VISHAY, CRCW0603130KFKEA
LINEAR TECH., LT8570EDD#PBF
TDK, C1608X7R1C104K
VISHAY, CRCW0805100KFKEA
MILL-MAX, 2501-2-00-80-00-00-07-0
Additional Demo Board Circuit Components
Hardware: For Demo Board Only
Additional Demo Board Circuit Components
Hardware: For Demo Board Only
4
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