DC2239A - Demo Manual

DEMO MANUAL DC2239A
LTC7860
High Efficiency Switching
Surge Stopper/EMI Filter
Description
Demonstration circuit 2239A is a High Efficiency Switching Surge Stopper and EMI Filter featuring the LTC®7860.
The board operates from an input range of 3.5V to 60V,
provides a 3.5V to 17.2V output at 0A to 5A and is output
current limited. A soft-start feature controls output voltage
slew rate at start-up, reducing current surge and voltage
overshoot. The demonstration board has options for
smaller MOSFET and diode packages on the back of the
board for lower output current requirements.
The LTC7860 high efficiency surge stopper protects loads
from high voltage transients. High efficiency compared to
linear circuits permits higher currents and smaller solution
sizes. During an input overvoltage event, such as a load
dump in vehicles, the LTC7860 controls the gate of an
external MOSFET to act as a switching DC/DC regulator
(PROTECTIVE PWM mode). This operation regulates the
output voltage to a safe level, allowing the loads to operate through the input over-voltage event. During normal
operation (SWITCH-ON mode), the LTC7860 turns on the
external MOSFET continuously, passing the input voltage
through to the output with minimum power loss.
Performance Summary
SYMBOL
PARAMETER
VIN
Input Supply Range
In addition, the output inductor and capacitor form an
L-C EMI filter when in SWITCH-ON mode. An internal
comparator limits the voltage across the current sense
resistor and regulates the maximum output current to
protect against overcurrent faults. An adjustable timer
limits the time that the LTC7860 can spend in overvoltage
or overcurrent regulation. When the timer expires, the
external MOSFET is turned off until the LTC7860 restarts
after a cool down period. By strictly limiting the time in
PROTECTIVE PWM Mode when the power loss is higher,
the components and thermal design can be optimized for
normal operation and safely operate through high voltage
input surges and/or overcurrent faults.
This board is suitable for a wide range of automotive,
telecom, industrial, and other applications. The LTC7860
is available in a Small 12-Pin Thermally Enhanced MSOP
Package. For other output requirements, see the LTC7860
data sheet or contact the LTC factory.
Design files for this circuit board are available at
http://www.linear.com/demo/DC2239A
L, LTC, LTM, LT, Burst Mode, OPTI-LOOP, Over-The-Top and PolyPhase are registered
trademarks of Linear Technology Corporation. Other product names may be trademarks of the
companies that manufacture the products.
Specifications are at TA = 25°C
CONDITIONS
MIN
TYP
3.5
VOUT
Output Voltage
IOUT
Output Current Range, Continuous
Free Air
3.5
VIN – VOUT
Insertion Loss
VIN =14V, IOUT = 5A
fSW
Switching (Clock) Frequency
During VIN Surge Only
TPWM
PROTECTIVE PWM Mode Time Limit
VOUT(P-P)
Output Ripple in PROTECTIVE PWM Mode
VIN = 40V, VOUT = 17.2V, IOUT = 5A (20MHz BW)
Approximate Size
Component Area x Top Component Height
14
0
MAX
60
V
17.5
V
5
A
245
mV
535
0.85
1.06
200
18 x 16 x 6
UNITS
kHz
1.24
s
mVP–P
mm
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1
DEMO MANUAL DC2239A
Quick Start Procedure
Demonstration circuit 2239 is easy to set up to evaluate
the performance of the LTC7860. Refer to Figure 1 for
proper measurement equipment setup and follow the
procedure below:
NOTE. When measuring the output voltage ripple, care must
be taken to avoid a long ground lead on the oscilloscope
probe. Measure the output voltage ripple by touching the
probe tip and ground ring directly across the last output
capacitor as shown in Figure 1.
1. Use an input power supply that is capable of 3.5V to
60V. Set its output to 5V. Then turn off the supply.
2. With power off, connect the supply to the input terminals
+VIN and –VIN.
a. Input voltages lower than 3.5V can keep the converter from turning on due to the undervoltage
lockout feature of the LTC7860.
b. A voltmeter with a capability of measuring at least
60V can be placed across the input terminals in order
to get an accurate input Voltage measurement.
3. Turn on the power at the input.
NOTE. Make sure that the input voltage never exceeds 60V.
2
4. Check for the proper output voltage of 5V. Turn off the
power at the input.
5. Connect a variable load capable of sinking 5A at 17.2V to
the output terminals +VOUT and –VOUT. Set the current
for 0A.
a. A voltmeter with a capability of measuring at least
18V can be placed across the output terminals in
order to get an accurate output voltage measurement.
6. Turn on the power at the input.
NOTE. If there is no output, temporarily disconnect the
load to make sure that the load is not set too high.
7. Once the proper output voltage is again established,
adjust the load and/or input within the operating range
up to 17VIN and observe the output voltage and other
desired parameters.
8. Now apply an input between 18V and 60V and observe
the output voltage and fault timer operation.
9. If desired, you may apply input transient profiles in
the range of 0VIN to 60VIN and observe the output to
illustrate operation of the circuit to prevent input surges
from reaching the output.
dc2239af
DEMO MANUAL DC2239A
Quick Start Procedure
–
–
+
VIN
+
+
–
VIN
+
–
VOUT
+
–
IIN
LOAD
+
–
IOUT
Figure 1. Proper Measurement Equipment Setup
VIN
10V/DIV
VOUT
10V/DIV
10ms/DIV
DC2239 F02
Figure 2. Output Response Waveform with 14V–60V–14V Input Surge, (5AOUT) (10V, 10V, 10ms/Div)
dc2239af
3
DEMO MANUAL DC2239A
Parts List
ITEM
QTY
REFERENCE
PART DESCRIPTION
MANUFACTURER/PART NUMBER
Required Circuit Components
1
1
CIN1
CAP., ALUM., 10µF, 63V, 20%, HVH Series
SUN ELECTRONIC INDUSTRIES CORPORATION,
63HVH10M
2
1
CIN2
CAP., 2.2µF, X7R, 100V, 10%, 1210
MURATA GRM32ER72A225KA35L
3
2
COUT1, COUT2
Cap., 10µF, X7R, 50V, 10%, 1210
MURATA GRM32ER71H106KA12
4
1
C1
CAP., 100pF, NP0, 25V, 5%, 0603
AVX 06033A101JAT2A
5
1
C2
CAP., 680pF, NP0, 25V, 5%, 0603
AVX 06033A681JAT2A
6
1
C4
CAP., 3.9pF, NP0, 50V, 5%, 0603
AVX 06035A3R9JAT2A
7
1
C5
CAP., 0.47µF, X5R, 16V, 20%, 0603
AVX 0603YD474MAT2A
8
1
C6
CAP., 0.1µF, X5R, 16V, 20%, 0603
AVX 0603YD104MAT2A
9
1
C7
Cap., 0.1µF, X5R, 100V, 20%, 0805
TDK, C2012X5R2A104M125AA
10
1
C8
CAP., 10pF, NP0, 50V, 5%, 0603
AVX 06035A100JAT2A
11
1
C10
CAP., 22µF, X7R, 6.3V, 10%, 1206
MURATA GRM31CR70J226KE19L
12
1
D2
DIODE, SCHOTTKY, 100V, 5A, PWRDI5
DIODES INC., PDS5100-7
13
1
D3
DIODE, ZENER, 9.1V, 500mW, SOD-123
ON SEMI., MMSZ9V1T1G
14
1
D5
DIODE, RECTIFIER, 30V, 500mA, SOD-123
DIODES INC., B0530W-7-F
15
1
L1
IND., PWR., SHIELDED, 6.8µH, 20%, XAL6060
COILCRAFT XAL6060-682MEC
16
1
Q2
XSTR., MOSFET P-CH, 60V, PWRPAK, S0-8
VISHAY Si7461DP-T1-GE3
17
1
R2
RES., 10k, 1/10W, 1%, 0603
VISHAY CRCW060310K0FKEA
18
1
R3
RES., 48.7k, 1/10W, 1%, 0603
VISHAY CRCW060348K7FKEA
19
1
R5
Res., 1M, 1/10W, 1%, 0603
VISHAY, CRCW06031M00FKEA
20
1
R7
RES., SENSE, 0.012Ω, 1/2W, 1%, 2010
VISHAY WSL2010R0120FEA
21
1
R8
RES., 1Ω, 1/10W, 1%, 0603
VISHAY, CRCW06031R00FKEA
22
1
U1
I.C., Voltage Reg. MSOP(12)-MSE
LINEAR TECH.CORP. LTC7860EMSE#PBF
Additional Demo Board Circuit Components
1
0
CIN3
CAP., OPTION, 1210
OPT
2
0
COUT3
CAP., OPTION, 0603
OPT
3
0
C9
CAP., OPTION, D CASE
OPT
4
0
D1
DIODE, OPTION, DFN3030-8
OPT
5
0
D4
DIODE, OPTION, SOD-323
OPT
6
0
Q1
XSTR, OPTION POWER_33
OPT
7
0
R1, R9, R11
RES., OPTION, 0603
OPT
8
4
R4, R6, R10, R12
RES., 0Ω, 1/10W, 5%, 0603
VISHAY, CRCW06030000Z0EA
Hardware: For Demo Board Only
1
4
E1, E2, E8, E9
TEST POINT, TURRET, 0.094" MTG. HOLE
MILL-MAX 2501-2-00-80-00-00-07-0
2
0
E10, E11
TEST PAD
TEST PAD
3
1
JP1
CONN., HEADER, 1X3, 2mm
SAMTEC TMM-103-02-L-S
4
4
J3, J4, J5, J6
CONN., JACK, BANANA, Non-Insulated, 0.218"
KEYSTONE, 575-4
5
1
XJP1
SHUNT, 2mm
SAMTEC 2SN-BK-G
6
4
4 CORNERS
7
1
4
STANDOFF, NYLON, SNAP-ON, 0.375"
KEYSTONE 8832
PCB, High Voltage Surge Suppressor with Timer
DEMO CIRCUIT 2239A
dc2239af
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.
A
B
C
D
R3
48.7K
1%
+
R4
0 Ohm
C4
3.9pF
5%
C10
22uF
1206
CIN1
10uF
63V
5
1. ALL RESISTORS AND CAPACITORS ARE 0603.
NOTE: UNLESS OTHERWISE SPECIFIED
GND
3.5V-60V
VIN
R1
R5
1.0M
1%
OPT
C2
680pF
R2
10.0K
1%
0.1uF
C6
FREQ
4
ITH
VFB
SS
GND
FREQ
TMR
C8
10pF
5%
6
5
4
3
2
1
13
GND
D5
JP1
2
3
SHDN
1
R10
0 Ohm
R11
VIN
ON
OFF
(D1 OPT)
D2
PDS5100-13
PowerDi5
OPT
0.1uF
100V
0805
C7
R6
0 Ohm
CUSTOMER NOTICE
D4
OPT
R9
OPT
VOUT
0.47uF
C5
C1
100pF
5%
1
R8
D3
MMSZ9V1T1G
R7
0.012
2010
XAL6060-682ME
COILCRAFT
3
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
L1
6.8uH
LT
SCALE = NONE
DAVID B.
2
COUT1
10uF
50V
1210
COUT2
10uF
50V
1210
DATE
GND
3.5V-17V
5A
VOUT
1/30/15
DAVID B.
APPROVED
DATE:
N/A
IC NO.
Thursday, March 26, 2015
1
LTC7860EMSE
DEMO CIRCUIT 2239A
SHEET
1
OF
1
1
REV.
LTC CONFIDENTIAL - FOR CUSTOMER USE ONLY
1630 McCarthy Blvd.
Milpitas, CA 95035 www.linear.com
Phone: (408)432-1900
Fax: (408)434-0507
COUT3
OPT
0603
1
HIGH VOLTAGE SURGE SUPPRESSOR WITH TIMER
SIZE
2
C9
OPT
7343
TECHNOLOGY
+
VOUT
DESCRIPTION
PRODUCTION
1
REVISION HISTORY
REV
TITLE: SCHEMATIC
ECO
APPROVALS
SW
(Q1 OPT)
Q2
Si7461DP
LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A
CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS;
HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO PCB DES.
VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL
APP ENG.
APPLICATION. COMPONENT SUBSTITUTION AND PRINTED
CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT
PERFORMANCE OR RELIABILITY. CONTACT LINEAR
TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
0 Ohm
R12
7
8
9
10
11
12
GATE
B0530W
3
Figure 3. DC2239A Demo Circuit Schematic
FREQ
VFBN
RUN
CAP
SENSE
VIN
GATE
CIN2
2.2uF
100V
1210
LTC7860EMSE
U1
CIN3
OPT
100V
1210
VIN
1
2
4
1
2
5
A
B
C
D
DEMO MANUAL DC2239A
Schematic Diagram
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5
DEMO MANUAL DC2239A
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
dc2239af
Linear Technology Corporation
LT 0415 • 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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