DC1850 - Demo Manual

DEMO MANUAL
DC1850A-A/DC1850A-B
LTC4366HTS8-1/LTC4366HTS8-2
Very High Voltage Surge Stopper
Description
Demonstration Circuit 1850A showcases the LTC®4366
high voltage surge stopper in a 28V vehicular application.
DC1850A withstands inputs of up to 100VDC and input
transients of up to 250V while maintaining the output at
43.1V. Reverse battery and errant inputs of up to –100VDC
are blocked from reaching the output.
DC1850A-A features latchoff behavior after a fault and is
reset by asserting the SHUTDOWN input high for at least
100µs. DC1850A-B features auto-retry 9 seconds after
tripping off in an overvoltage fault condition. The 9 second
delay can be interrupted by pulsing the SHUTDOWN input.
Design files for this circuit board are available at
http://www.linear.com/demo
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
PARAMETER
CONDITIONS
Input Range
Operating
DC Survival
1ms Transient
Load = 1.5A
Specifications are at TA = 25°C
Output Regulation
Surge Timer
Cool-Down Timer
Input = 100V (DC1850A-B)
MIN
TYP
MAX
UNITS
18
–100
250
28
41
100
V
V
V
41
43.1
45.3
V
1.2
5.9
2.8
9
4.9
16
ms
s
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DEMO MANUAL
DC1850A-A/DC1850A-B
Overview
The LTC4366 surge stopper operates in a floating topology, permitting the design of circuits capable of operating
at virtually unlimited input voltage. DC1850A has been
designed to protect against ±100VDC and 250V for 1ms,
in 28V vehicle applications. The input start-up range is
18V to 41V, while after start-up the input can fall to approximately 7V while still passing 1.5A load current.
Careful attention has been paid to the layout to provide at
least 87mil (2.2mm) clearance between input and output,
and input and ground. This wide clearance is capable of
withstanding 100VDC and spikes to 250V without arcing.
The operating ranges are shown in silkscreen on the top
of the board. The bottom shows the U1 part number, top
mark and behavior associated with the –A and –B versions of DC1850A. This same information is shown on
the schematic.
Three ancillary circuits are located on the bottom of the
board.
Shutdown Level Shifter
Since the LTC4366 operates in a floating topology, it is
necessary to level shift ground-referred shutdown signalling. A simple NPN circuit provides level shifting between
the SHUTDOWN turret and the LTC4366’s SD pin.
Wide Voltage Range Constant Current LED Driver
Making an LED operate at constant brightness over a
wide operating range is made possible by a simple, twotransistor circuit. Input LED (D6) current is held constant
from 18V to 250V, and emits some light as low as 7V.
Output LED (D5) is biased with a 9.1k resistor (R7, on bottom of board). Its brightness will vary with output voltage.
−100V Reverse Voltage Protection Circuit
Reverse polarity inputs of up to −100V are blocked from
reaching the load by M2, whose associated circuitry is
located on the bottom of the board. This circuit blocks
reverse inputs of up to −250VDC, provided the input is
applied from a cold start. If DC1850A is already on and
operating with a positive input voltage, instantaneous
spikes must not exceed −100V.
SHUTDOWN Turret
If the SHUTDOWN turret is left open, DC1850A defaults
to the ON state and turns on when an input supply is
connected. Pulling SHUTDOWN to 1.8V or higher causes
the LTC4366 to enter its shutdown state. The circuit
board layout limits the maximum SHUTDOWN voltage to
60VDC, while R2 limits the peak applied transient voltage
capability to 100V.
Optional Components
Two optional components, CX and RX are made available
for those who wish to experiment with the frequency
response of the overvoltage regulation loop.
How to Operate DC1850A
Operation of DC1850A is straightforward: connect an
input supply of 18V to 41V, and an output load of up to
1.5A. If the SHUTDOWN turret is open circuit the output
will power up. If the input voltage is increased above
≈ 43.1V, the output will limit and shut off after 2.8ms. DC
inputs of up to ±100V may be applied. The basic hookup
is shown in Figure 1.
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DEMO MANUAL
DC1850A-A/DC1850A-B
Overview
18V TO 41V
INPUT
0A TO 1.5A
LOAD
Figure 1. DC1850A Basic Hookup
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DEMO MANUAL
DC1850A-A/DC1850A-B
Parts List
ITEM
QTY
REFERENCE
PART DESCRIPTION
MANUFACTURER/PART NUMBER
1
2
1
CF
CAP., X7R, 1000pF 100V, 10%, 0603
AVX, 06031C102KAT2A
2
CT, CG
CAP., X7R, 0.01µF 100V, 10%, 0603
AVX, 06031C103KAT2A
3
1
CLOAD
CAP., ALUM. 100µF 50V, 20%
SUN ELECT, 50CE100LX
4
1
C1
CAP., X7R, 0.47µF 25V, 10%, 0603
AVX, 06033C474KAT2A
5
0
CX (OPT)
CAP., X7R, 0.01µF 100V, 10%, 0603
6
1
CSNUB
CAP., X7R, 0.01µF 500V, 20%, 1210
AVX, 12107C103MAT2A
7
5
D1, D2, D3, D4, D7
DIODE, SWITCH 300V 400MW SOD123
DIODES INC, BAV3004W-7-F
8
2
D5, D6
LED, GREEN S-GW TYPE SMD
PANASONIC, LN1371SGTRP
9
6
E1, E3, E4, E5, E6, E8
TESTPOINT, TURRET, .094"
MILL-MAX, 2501-2-00-80-00-00-07-0
10
4
E18, E19, E20, E21
JACK, BANANA
KEYSTONE, 575-4
11
2
M1, M2
MOSFET, N-CH 250V 33A D2PAK
FAIRCHILD, FDB33N25TM
12
3
Q1, Q2, Q3
TRANSISTOR, GP NPN AMP SOT-23
DIODES INC, MMBT3904-7-F
13
1
Q4
TRANS., AMP NPN GP 300V SOT-223
FAIRCHILD, PZTA42 TR
14
1
RFB1
RES., CHIP, 12.4k, 1%, 0603
NIC, NRC06F1242TRF
15
1
RFB2
RES., CHIP, 422k, 1%, 0603
NIC, NRC06F4223TRF
16
1
RG
RES., CHIP, 10, 5%, 0603
NIC, NRC06J100TRF
17
1
RSS
RES., CHIP, 34k, 1%, 0603
VISHAY, CRCW060334K0FKEA
18
1
RIN
RES., CHIP, 392k, 1%, 1206
VISHAY, CRCW1206392KFKEA
19
4
R1, R2, R3, R5
RES., CHIP, 470k, 5%, 0603
NIC, NRC06J474TRF
20
3
R4, R6, R9
RES., CHIP, 270k, 5%, 1206
NIC, NRC12J274TRF
21
1
R7
RES., CHIP, 9.1k, 5%, 1206
NIC, NRC12J912TRF
22
1
R8
RES., CHIP, 4.7k, 5%, 0603
NIC, NRC06J472TRF
23
1
R10
RES., CHIP, 200, 5%, 0603
NIC, NRC06J201TRF
24
0
RX (OPT)
RES., CHIP, 100k, 1%, 0603
25
1
RSNUB
RES., CHIP,100Ω, 5%, 1210
NIC, NRCP25J101TRF
26
4
STAND OFF
STAND OFF 0.375"
KEYSTONE, 8832
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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
E21
INPUT
18V - 41V
MMBT3904
Q3
2
1
R10
200
5
R2 470k
LTFMF
4
PART MARKING
E8
E1
DC1850A-B LTC4366HTS8-2
U1
GND
SHUTDOWN
Q1
MMBT3904
AUTO RETRY
CT
10nF
100V
E5
VSS
TIMER
SD
VDD
E19
E20
GND
RSS
34k
U1*
CUSTOMER NOTICE
4
3
2
1
3
E4
BASE
FB
OUT
GATE
3
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A
CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS;
HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO
VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL
APPLICATION. COMPONENT SUBSTITUTION AND PRINTED
CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT
PERFORMANCE OR RELIABILITY. CONTACT LINEAR
TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
R1 470k
LATCH OFF
RIN
392k
CF
1nF
100V
D2
BAV3004W
D1
BAV3004W
1
2
BEHAVIOR
R3
470k
1
SHUTDOWN
LEVEL SHIFTER
PROTECTION CIRCUIT
-100V REVERSE VOLTAGE
1
LTFMC
ASSY
D
R4 270k
Q2
MMBT3904
3
4
G
DC1850A-A LTC4366HTS8-1
*
2
M2
S
FDB33N25
R5
470k
PART NUMBER
D6
GREEN
INPUT
Q4
PZTA42
R8
4.7k
D7
BAV3004W
R6
270k
D4
BAV3004W
D3
BAV3004W
WIDE VOLTAGE RANGE
CONSTANT CURRENT
LED DRIVER
1
R9
270k
1
2
1
1
2
1
E6
3
2
4
3
SCALE = NONE
HZ
Mitchell L.
PCB DES.
2
DATE:
N/A
SIZE
1.5A
MAXIMUM LOAD
LTC4366HTS8 FAMILY
DEMO CIRCUIT 1850A
Wednesday, June 20, 2012
IC NO.
DATE
6-5-12
1
SHEET 1
OF 1
3
REV.
1630 McCarthy Blvd.
Milpitas, CA 95035
Phone: (408)432-1900 www.linear.com
Fax: (408)434-0507
LTC Confidential-For Customer Use Only
2.8ms
43.1V
SURGE TIMER
OUTPUT CLAMP
E18
VERY HIGH VOLTAGE SURGE STOPPER
TECHNOLOGY
250V
1ms TRANSIENT
TITLE: SCHEMATIC
+/- 100V
CLOAD
100uF
50V
E3
Mitchell L.
APPROVED
OUTPUT
1.5A MAXIMUM
CLAMPED AT 43.1V
DESCRIPTION
PRODUCTION
CSNUB
10nF
500V
18V - 41V
1
REVISION HISTORY
RSNUB
100
+
D5
GREEN
OUTPUT
R7
9.1k
INPUT RANGE
RFB2
422k
RFB1
12.4k
M1
FDB33N25
3
REV
DC SURVIVAL
G
__
ECO
DC OPERATING
CX
10nF
100V
OPT
RX
OPT
100k
10
APPROVALS
C1
470nF
25V
CG
10nF
100V
RG
APP ENG.
5
6
7
8
2
D
S
2
3
2
5
A
B
C
D
DEMO MANUAL
DC1850A-A/DC1850A-B
Schematic Diagram
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DEMO MANUAL
DC1850A-A/DC1850A-B
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.
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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
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.
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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
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Linear Technology Corporation
LT 1012 • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900
●
FAX: (408) 434-0507 ● www.linear.com
 LINEAR TECHNOLOGY CORPORATION 2012
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