DC2010A - Demo Manual

DEMO MANUAL DC2010A
LT8612
42V, 6A Micropower Synchronous
Step-Down Regulator
Description
Demonstration circuit 2010A is a 42V, 6A micropower
synchronous step-down regulator featuring the LT®8612.
The demo board is designed for 5V output from a 5.8V
to 42V input. The wide input range allows a variety of
input sources, such as automotive batteries and industrial
supplies. The LT8612 is a compact, high efficiency, and
high speed synchronous monolithic step-down switching
regulator. The integrated power switches and inclusion
of all necessary circuitry reduce the components count
and solution size. Ultralow 3μA quiescent current in Burst
Mode® operation achieves high efficiency at very light
loads. Fast minimum on-time of 40ns enables high VIN
to low VOUT conversion at high frequency.
The LT8612 switching frequency can be programmed
either via oscillator resistor or external clock over a 200kHz
to 2.2MHz range. The SYNC pin on the demo board is
grounded by default for low ripple burst mode operation.
To synchronize to an external clock, move JP1 to SYNC
and apply the external clock to the SYNC turret. Once JP1
is on SYNC position, a DC voltage of 3V or higher can be
applied to the SYNC turret for pulse-skipping operation.
Performance Summary
SYMBOL
PARAMETER
VIN
Input Supply Range
VOUT
Output Voltage
IOUT
Maximum Output Current
fSW
Switching Frequency
EFE
Efficiency at DC
Figure 1 shows the efficiency of DC2010A circuit at 12V
input. Figure 2 shows the LT8612 temperature rising on
DC2010A demo board under different load conditions.
The rated maximum load current is 6A, while derating is
necessary for certain VIN and thermal conditions. The demo
board has an EMI filter installed. To use the EMI filter, the
input should be tied to VEMI terminal, not VIN terminal.
The LT8612 data sheet gives a complete description of
the part, operation and application information. The data
sheet must be read in conjunction with this demo manual
for demo circuit 2010A. The LT8612 is assembled in a
3mm × 6mm plastic QFN package with exposed pads for
low thermal resistance. Proper board layout is essential for
minimum EMI and maximum thermal performance. See
the data sheet section PCB Layout and High Temperature
Considerations.
Design files for this circuit board are available at
http://www.linear.com/demo/DC2010A
L, LT, LTC, LTM, Linear Technology, Burst Mode and the Linear logo are registered trademarks
of Linear Technology Corporation. All other trademarks are the property of their respective
owners.
Specifications are at TA = 25°C
CONDITIONS
MIN
TYP
5.8
4.875
Derating Is Necessary for Certain VIN and Thermal Conditions
42
5
5.125
6
665
VIN = 12V , IOUT = 3A
MAX
UNITS
V
V
A
700
94.3
735
kHz
%
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DEMO MANUAL DC2010A
Description
80
95
70
TEMPERATURE RISING (°C)
100
EFFICIENCY (°C)
90
85
80
75
70
VIN = 12V
VOUT = 5V
fSW = 700kHz
SYNC = GND
65
60
0
1
2
4
3
LOAD CURRENT (A)
5
VOUT = 5V
fSW = 700kHz
60
IOUT = 6A
50
IOUT = 5.5A
40
IOUT = 5A
IOUT = 4.5A
30
20
IOUT = 4A
10
6
dc2010a F01
Figure 1. Efficiency vs Load Current (Using VIN Terminal)
0
6
12
18
30
24
INPUT VOLTAGE (V)
36
42
dc2010a F02
Figure 2. Temperature Rising vs Input Voltage
Quick Start Procedure
Demonstration circuit 2010A is easy to set up to evaluate the performance of the LT8612. Refer to Figure 3 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 4 for the proper
scope technique.
1.Place JP1 on GND position.
2.With power off, connect the input power supply to VIN
and GND.
3.With power off, connect the load from VOUT to GND.
4.Turn on the power at the input.
2
NOTE. Make sure that the input voltage does not
exceed 42V.
5.Check for the proper output voltage (VOUT = 5V).
NOTE. If there is no output, temporarily disconnect the
load to make sure that the load is not set too high or
is shorted.
6.Once the proper output voltage is established, adjust
the load within the operating ranges and observe the
output voltage regulation, ripple voltage, efficiency and
other parameters.
7.An external clock can be added to the SYNC terminal
when SYNC function is used (JP1 on the SYNC position). Please make sure that RT should be chosen to
set the LT8612 switching frequency equal to or below
the lowest SYNC frequency. See the data sheet section
Synchronization.
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DEMO MANUAL DC2010A
Quick Start Procedure
Figure 3. Proper Measurement Equipment Setup
Figure 4. Measuring Output Ripple
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DEMO MANUAL DC2010A
Parts List
ITEM
QTY
REFERENCE
PART DESCRIPTION
MANUFACTURER/PART NUMBER
Required Circuit Components
1
1
C2
CAP., X5R, 10µF, 50V, 10% 1210
MURATA, GRM32ER61H106KA12L
2
1
C8
CAP., X7R, 0.1µF, 25V, 10% 0603
MURATA, GRM188R71E104KA01D
3
1
C5
CAP., C0G, 10pF, 25V, 5% 0603
AVX, 06033A100JAT2A
4
1
C6
CAP., X5R, 100µF, 10V, 20% 1210
SAMSUNG, CL32A107MPVNNNE
5
2
C7, C9
CAP., X7R, 1.0µF, 25V, 10% 0603
MURATA, GRM188R71E105KA12D
6
2
C4, C15
CAP., X7R, 0.1µF, 50V, 10% 0402
TDK, C1005X7R1H104K
7
1
L1
IND., 3.3µH, IHLP2525EZ-01
VISHAY, IHLP2525EZER3R3M01
8
2
R1, R3
RES., CHIP., 100k, 1/10W, 1% 0603
VISHAY, CRCW0603100KFKEA
9
1
R2
RES., CHIP., 60.4k, 1/10W, 1% 0603
VISHAY, CRCW060360K4FKEA
10
1
R4
RES., CHIP., 1M, 1/10W, 1% 0603
VISHAY, CRCW06031M00FKEA
11
1
R5
RES., CHIP., 243k, 1/10W, 1%, 0603
VISHAY, CRCW0603243KFKEA
12
1
U1
IC, REGULATOR, 28-QFN, UDE
LINEAR TECH., LT8612EUDE#PBF
Additional Demo Board Circuit Components
1
1
C1
CAP., ALUM 22µF, 63V
SUN ELECT., 63CE22BS
2
2
C3, C10
CAP., X5R, 10µF, 50V, 10% 1210
MURATA, GRM32ER61H106KA12L
3
1
C14
CAP., X7R, 0.1µF, 50V, 10% 0402
TDK, C1005X7R1H104K
4
0
C11 (OPT)
CAP., 0603
5
1
L2
FERRITE BEAD 100Ω 8A SMD 1812
WURTH, 74279226101
6
1
L3
IND., 6.8µH, IHLP3232DZ-11
VISHAY, IHLP3232DZER6R8M11
7
0
R6 (OPT)
RES., 0402
8
1
R7
RES., CHIP., 0Ω, 1/10W, 1%, 0603
VISHAY, CRCW06030000Z0EA
Hardware: For Demo Board Only
1
10
E1-E10
TESTPOINT, TURRET, 0.094"
MILL-MAX, 2501-2-00-80-00-00-07-0
2
1
JP1
HEADER, 3 PIN 0.079" SINGLE ROW
SULLINS, NRPN031PAEN-RC
3
1
XJP1
SHUNT, 0.079" CENTER
SAMTEC, 2SN-BK-G
4
4
MH1-MH4
STAND-OFF, NYLON 0.50" TALL
KEYSTONE, 8833(SNAP ON)
4
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VEMI
TR/SS
GND
SYNC
EN/UV
GND
E10
E7
E9
E5
E6
E2
E1
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 representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
JP1
1
2
3
C3
10uF
50V
1210
L2
1812
WE 74279226101
SYNC
GND
SUNCON
63CE22BS
22uF
63V
+ C1
C7
1uF
25V
C8
0.1uF
C15
0.1uF
0402
C10
10uF
50V
1210
L3
6.8uH
IHLP3232DZER6R8M11
VIN
C2
10uF
50V
1210
1. ALL RESISTORS ARE 0603.
ALL CAPACITORS ARE 0603.
NOTES: UNLESS OTHERWISE SPECIFIED
C14
0.1uF
50V
0402
VIN
R2
60.4k
700KHz
R6
OPT
R1
100K
8
9
10
3
2
21
1
4
5
6
7
PGND
PGND
PGND
RT
TR/SS
INTVCC
SYNC
EN/UV
VIN
VIN
VIN
U1
LT8612EUDE
GND
GND
GND
GND
11
12
13
14
GND
29
FB
PG
BIAS
SW
SW
SW
SW
SW
BST
NC
NC
NC
NC
25
26
27
28
VIN
5.8V - 42V
24
23
22
15
16
17
18
19
20
0
R7
L1
3.3uH
R5
243k
10pF
C5
1Meg
R4 100K
R3
IHLP2525EZER3R3M01
C4
0.1uF
0402
*
E8
E4
E3
PG
GND
VOUT
5V / 6A
*
SEE DEMO MANUAL
C9
1uF
C11
OPT
C6
100uF
10V
1210
VOUT
DEMO MANUAL DC2010A
Schematic Diagram
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DEMO MANUAL DC2010A
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
6
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Linear Technology Corporation
LT 0915 REV A • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900
●
FAX: (408) 434-0507 ● www.linear.com
 LINEAR TECHNOLOGY CORPORATION 2014
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