DC1506A - Demo Manual

DEMO MANUAL DC1506A
LTC4361 Overvoltage/
Overcurrent Protection
Controller
DESCRIPTION
Demonstration circuit DC1506A features the LTC®4361
an overvoltage/overcurrent protection controller that
safeguards 2.5V to 5.5V systems from input supply overvoltage. The LTC4361 is designed for portable devices with
multiple power supply options including wall adapters, car
battery adapters and USB ports.
The LTC4361 controls an external N-channel MOSFET in
series with the input power supply. During overvoltage
transients, the LTC4361 turns off the MOSFET within 1µs,
isolating downstream components from the input supply.
Inductive cable transients are absorbed by the MOSFET
and load capacitance. In most applications, the LTC4361
provides protection from transients up to 80V without
requiring transient voltage suppressors or other external
components.
The LTC4361 has a delayed start-up and adjustable
dV/dt ramp-up for inrush current limiting. A PWRGD pin
provides power good monitoring for VIN. The LTC4361
features a soft shutdown controlled by the ON pin and
drives an optional external P-channel MOSFET for negative
voltage protection. Following an overvoltage condition,
the LTC4361 automatically restarts with a start-up delay.
After an overcurrent fault, the LTC4361-1 remains off
while the LTC4361-2 automatically restarts after a 130ms
start-up delay.
DC1506A demonstrates three protection schemes selected
with a jumper: (A) overvoltage and overcurrent protection, (B) overvoltage, overcurrent, and negative voltage
protection, and (C) overvoltage, overcurrent, negative
voltage, and reverse current protection. Each option has
ON control, an output LED and can be applied to a USB
protected output.
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.
1506a FO1
Figure 1. Demonstration Circuit 1506A
dc1506af
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DEMO MANUAL DC1506A
PERFORMANCE SUMMARY
Table 1. Typical DC1506A Performance Summary (TA = 25°C)
PARAMETER
CONDITION
VALUE
Input Voltage
Protection (A) OV
Protection (B) OV/OC/NV
Protection (C) OV/OC/NV/RC
0V to 30V
–30V to 30V
–30V to 30V
Output Voltage
Input Range for Gate Turn-On
2.1V to 5.8V
Overcurrent Threshold
51mΩ Sense Resistor
980mA
Overcurrent Retry
Protection (A) OV/OC, LTC4361-1
Protection (B) OV/OC/NV, LTC4361-2
Protection (C) OV/OC/NV/RC, LTC4361-1
Latchoff
Auto-Retry
Latchoff
QUICK START PROCEDURE
Demonstration circuit description 1506A is easy to set
up to evaluate the performance of the LTC4361. Refer to
Figure 2 and Figure 3 for proper measurement equipment
setup and follow the procedure below.
1. Connect a power supply across VIN and GND.
2. Select ENABLE at JP2 to enable the protection.
3.Select protection type at JP1 and connect a load and
voltmeter across the corresponding output and GND:
a.For overvoltage and overcurrent protection select
(A) OV/OC and connect to OUT(A). Figure 2a.
protection select (B) OV/OC/NV and connect to
OUT(B). Figure 2b.
c.For overvoltage, overcurrent, negative voltage,
and reverse current protection select (C) OV/OC/
NV/RC, connect to OUT(C). Figure 2c.
4.For USB protection, connect a USB cable from J2 to
the USB device (Figure 3). Select the protection type
at JP1 and match JP3 to JP1. Connect a second USB
cable from a computer to J1.
b.For overvoltage, overcurrent and negative voltage
dc1506af
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DEMO MANUAL DC1506A
QUICK START PROCEDURE
SELECT
PROTECTION
(A)
OVERVOLTAGE,
OVERCURRENT
PROTECTED
OUT
A
PWRGD
V
LOAD
+
–
VIN
SELECT
ENABLE
1506a FO2a
Figure 2a. DC1506A Protection (A) Setup for Overvoltage and Overcurrent
dc1506af
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DEMO MANUAL DC1506A
QUICK START PROCEDURE
SELECT
PROTECTION
(B)
+
–
VIN
OVERVOLTAGE,
OVERCURRENT,
NEGATIVE VOLTAGE
PROTECTED OUT
A
PWRGD
V
LOAD
SELECT
ENABLE
1506a FO2b
Figure 2b. DC1506A Protection (B) Setup for Overvoltage, Overcurrent and Negative Voltage
SELECT
PROTECTION
(C)
+
–
VIN
OVERVOLTAGE,
OVERCURRENT,
NEGATIVE VOLTAGE,
REVERSE CURRENT
PROTECTED OUT
A
V
LOAD
SELECT
ENABLE
PWRGD
1506a FO2c
Figure 2c. DC1506A Protection (C) Setup for Overvoltage, Overcurrent, Negative Voltage, and Reverse Current
dc1506af
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DEMO MANUAL DC1506A
QUICK START PROCEDURE
HOT
PLUG
USB CABLE
USB CABLE
PC
USB DEVICE
SELECT
PROTECTION
SELECT USB PROTECTION
(JP3 MUST MATCH JP1)
SELECT ENABLE
1506a FO3
Figure 3. DC1506A USB Protection Setup
dc1506af
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DEMO MANUAL DC1506A
QUICK START PROCEDURE
OPERATION
The DC1506A is used to evaluate the LTC4361 in three
protection configurations selected at JP1. The device in
need of protection is connected to one of the three OUT test
points or to the USB output connector J2. An input supply
is connected at VIN or a USB source is connected at J1.
ON Control
The ON pins on each of the three LTC4361s are tied together
and controlled at JP2. Select ENABLE to enable the selected
protection, or DISABLE to enter a low current sleep mode.
Protection (A) OV/OC
The first selection at JP1 is protection (A) OV/OC which
protects against overvoltage and overcurrent. The LTC4361
turns on a single N-channel MOSFET when the input voltage is below the overvoltage threshold. A Kelvin sense to
the sense resistor in series with the power path provides
overcurrent detection. In the case of an overcurrent, the
LTC4361-1 used in protection (A) latches off and requires
a power cycle to turn the MOSFET back on. An amber
input LED indicates if the input supply is on while a green
OUT(A) LED indicates the gate is on and the input is passed
over to the output.
Protection (B) OV/OC/NV
The second selection at JP1 is protection (B) OV/OC/NV
which protects against overvoltage, overcurrent and negative voltage. The LTC4361 turns on an N-channel MOSFET
when the input voltage is below the overvoltage threshold.
A P-channel MOSFET is driven by the GATEP pin of the
LTC4361 to protect the output against an inadvertent
negative voltage connection at the input. A Kelvin sense to
the sense resistor in series with the power path provides
overcurrent detection. In the case of an overcurrent, the
LTC4361-2 used in protection (B) automatically retries to
turn the MOSFET back on. The amber VIN LED indicates if
the input supply is on while a green OUT(B) LED indicates
the gate is on and the input is passed over to the output. A
red –VIN LED indicates if a negative input voltage is present.
Protection (C) OV/OC/NV/RC
The third selection at JP1 is protection (C) OV/OC/NV/RC
which protects against over voltage, overcurrent, negative voltage and reverse current. The LTC4361 turns on
back-to-back N-channel MOSFETs when the input voltage
is below the overvoltage threshold. The back-to-back
N-channel MOSFETs blocks reverse current feeding in to
the input. A P-channel MOSFET is driven by the GATEP pin
of the LTC4361 to protect the output against an inadvertent
negative voltage connection at the input. A Kelvin sense to
the sense resistor in series with the power path provides
overcurrent detection. In the case of an overcurrent, the
LTC4361-1 used in protection (C) latches off and requires
a power cycle to turn the MOSFET back on. The amber
VIN LED indicates if the input supply is on while a green
OUT(C) LED indicates the gate is on and the input is passed
over to the output. The red –VIN LED indicates if a negative
input voltage is present.
USB Protection
DC1506A also provides connection for USB protection.
First connect a USB device with a USB cable at J2. Select
the protection type at JP1 and match this with JP3. Select
ENABLE at JP2. The USB source can then be connected
at J1.
dc1506af
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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
GND
D+
D-
VCC
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D+
D-
VCC
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3
SENSE
ON

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GND
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GND
GATEP
IN
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SENSE
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OUT
OUT
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2

Dilian R.

APPROVALS
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GATE
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GND
PWRGD
GATE
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REV
ECO
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PWRGD
OUT
GND

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ON

GATE
GND
GATEP
IN
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ON
GATEP
IN
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SENSE
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3
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TECHNOLOGY
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DATE
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APPROVED
DESCRIPTION
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REVISION HISTORY
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B
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DEMO MANUAL DC1506A
SCHEMATIC DIAGRAM
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DEMO MANUAL DC1506A
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
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Linear Technology Corporation
LT 1010 • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507
●
www.linear.com
 LINEAR TECHNOLOGY CORPORATION 2010
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