Linear Technology LTC4231 Quick setup guide

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DEMO MANUAL DC2161A
DESCRIPTION
LTC4231 Micropower
Hot Swap Controller
Demonstration circuit 2161A showcases the LT C
®
4231
Micropower Hot Swap
™
Controller in a 12V, 3A applica-
tion. Included on the board are input overvoltage and
reverse voltage protection, input voltage dividers for UV
and OV detection, an output voltage LED, jumpers to
disable UV/OV, manual and remote enable control, and
quiescentcurrentmeasurement.Thereareturretsprovided
to monitor input voltage, output voltage, output status,
quiescent current, several ground connections, timer pin,
and control the ON pin. Input, output and return voltages
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and Hot
Swap is a trademark of Linear Technology Corporation. All other trademarks are the property of
their respective owners.
are provided on banana jacks. The DC2161A-A version is
used to demonstrate the LTC4231-1 which remains off
after a current fault, while the DC2161A-B demonstrates
the LTC4231-2 which automatically reapplies power after
a cool-down period.
Design files for this circuit board are available at
http://www.linear.com/demo/DC2161A
Table 1
PARAMETER CONDITIONS VALUE
Input Supply Voltage Range Limited by Transient Surge Protector –24V to +24V
Nominal Operating Voltage  12V
Overvoltage Lockout Nominal 14.4V
Undervoltage Lockout (Voltage Falling) Nominal 9.6V
Undervoltage Lockout (Voltage Rising) Nominal 10.8V
Output Current Limit  3A
Maximum Load Capacitance  600µF
Timer Expiration Period  2ms
Table 2. Power Input and Output Connections
NOMENCLATURE CONNECTOR DESCRIPTION
VIN 12V J1 12V Input
GND J2 12V Input Return
VOUT 12V, 3A J3 12V Output
GND J4 12V Output Return
Table 3. Test Points
NOMENCLATURE TURRET DESCRIPTION
VIN 12V E1 12V Input Monitor
GND E2, E4,
E6, E8
Ground
VOUT 12V, 3A E3 12V Output Monitor
STATUS E5 Status, Open Drain when Output
Enabled
GND E6 Ground
IQ E7 Quiescent Current Monitor. Use
Microammeter at This Point When JP2
Selects MEASURE IQ.
ON E9 Enable LTC4231 Output. Enables Output
or Selects External Control of Output
TIMER E10 TIMER Pin
PERFORMANCE SUMMARY
Specifications are at TA= 25°C

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DEMO MANUAL DC2161A
DC2161A contains 3 jumpers. A description of each
jumper follows.
JP1, UV/OV.This jumper selects whether ornot undervolt-
ageor overvoltage lockout is enabled. When the jumper
is in the disable position, a UV or OV condition will not
block operation of the Hot Swap Controller. The default
is ENABLE.
JP2, IQ. The LTC4231 is a low power device, meaning it
draws very little current to perform its function. Any board
leakage on the GATE pin caused by board contamination or
adefectiveMOSFETwillcause this current to increase. JP2,
whenintheMEASUREIQposition,facilitatesmeasurement
of the quiescent current of the LTC4231 exclusive of the
current of other components on the board, such as LED
OPERATING PRINCIPLES
D2, output coupling capacitor C3, TVS diode D1, capacitor
C1, voltage divider R6, R7, R8 and R9, or any leakage on
the board. This current is measured via a microammeter
connected between turret E7 and GND. If the MEASURE IQ
position is selected, verify a microammeter is connected
to prevent damage to the board via leakage between VIN
and the gate of the MOSFETs. The default position for JP2
is NORMAL.
JP3, ENABLE. This jumper either enables or disables the
output or provides external control of the output. This is
provided by the ON pin of the LTC4231. When in the ON
position, the 12V VOUT is enabled. When in the OFF posi-
tion, the 12V VOUT is disabled. When in the EXT position,
the ON pin is connected via a 100kΩ resistor from turret
E9 to the ON pin of the LTC4231. A logic 1 on this pin will
enable the 12V VOUT. The default position for JP3 is ON.
The LTC4231 is a Micropower Hot Swap Controller that
has a 2.7V to 36V operating range and a –40V to 40V ab-
solute maximum voltage for the IN pin. This demo circuit
is populated for +12V operation, but it can easily be re-
adjusted for any voltage between 2.7V and 36V by replac-
ing R6, R7, R8, and R9 in the UVL, UVH, and OV divider
string. These values should be selected using guidelines
suggested in the LTC4231 data sheet to minimize current
drain. The DC2161A is populated with a Si7960DP dual
MOSFET with one section used as a pass MOSFET and the
other section used for reverse voltage protection. It also
has a 15mΩ sense resistor. This combination provides
an output current of 3A. Pads are provided on the PCB
for external MOSFET and sense resistor connections for
other voltages and currents.
JUMPERS

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DEMO MANUAL DC2161A
DC2161A is easy to set up to evaluate the performance
of the LTC4231.
Connect a power supply capable of delivering greater than
3.5A of current between 10V and 20V to the VIN jack J1
with its return lead connected to GND J2. Monitor the input
voltage at turrets E1 and E2. Place a voltmeter between
turrets E3 and E4. Connect an ammeter between J3 and the
test loads. Connect the return lead of the test loads to jack
J4. The connections are shown schematically in Figure 1.
The active load should be set to provide a resistive load
since the LTC4231 may not start into a constant current
load. With the resistive load set at 5.4Ω, vary the input
voltage from 9V to 17V and from 17V to 9V to check the
UV and OV thresholds.
QUICK START PROCEDURE
Set the input voltage to 12V, vary the load resistance, and
observe output indicator D2. Determine from the ammeter
that the output remains on at 3A(4Ω). The output should
turn off at approximately 3.2A.
Reduce the load resistance to below 4Ω and observe an
auto reset in the DC2161A-B. In the DC2161A-A, power
will have to be removed and then applied to the input to
reset the LTC4231.
Remove the resistive load from the output and replace it
with a 500µF capacitor. Observe the polarity when con-
necting the capacitor. Upon application of input voltage,
LED D2 should illuminate to indicate VOUT is present. This
indicates the Hot Swap Controller is capable of starting
into a 500µF capacitor.
Figure 1. Proper Equipment Measurement Set-Up
V
A
TEST
LOADS
V
POWER
SUPPLY

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DEMO MANUAL DC2161A
PARTS LIST
ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER
1 1 C1 CAP., X7R, 0.1µF 25V, 10%, 0603 MURATA, GRM188R71E104KA01D
2 0 C2 CAP., 0402 OPT
3 1 C3 CAP., TANT, 100µF 25V, 20%, 7343 AVX, TAJE107M025RNJ
4 1 C4 CAP., X7R, 0.082µF 16V, 10%, 0402 MURATA, GRM155R71C823KA88D
5 1 D1 DIODE, SUPPRESSORS,600W, SMB-DIODE FAIRCHILD SEMI., SMBJ24CA
6 1 D2 LED, GREEN, LED-ROHM-SML-010 ROHM, SML-010FTT86
7 10 E1-E10 TURRET, TESTPOINT 0.064" MILL-MAX, 2308-2-00-80-00-00-07-0
8 2 JP1, JP2 HEADER, 2mm SINGLE 3POS SULLINS, NRPN031PAEN-RC
9 1 JP3 HEADER, 2mm DOUBLE 3POS SAMTEC, TMM-103-02-L-D
10 4 J1, J2, J3, J4 JACK, BANANA KEYSTONE, 575-4
11 1 Q1 MOSFET, DUAL-CH, 60V, SO8-POWERPAK VISHAY SILICONIX, Si7960DP-T1-GE3
12 1 R1 RES., CHIP, 10, 1/16W, 1%, 0603 VISHAY, CRCW060310R0FKEA
13 1 R2 RES., SENSE, 0.015, 1/4W, 1%, 1206 VISHAY, WSL1206R0150FEA
14 1 R3 RES., CHIP, 10, 1/16W, 1%, 0402 VISHAY, CRCW040210R0FKED
15 0 R4 RES., 0402 OPT
16 1 R5 RES., CHIP, 3.32kΩ, 1/16W, 1%, 0603 VISHAY, CRCW06033K32FKEA
17 1 R6 RES., CHIP, 1.24MΩ, 1/8W, 1%, 0805 VISHAY, CRCW08051M24FKEA
18 1 R7 RES., CHIP, 12.4kΩ, 1/16W, 1%, 0402 VISHAY, CRCW040212K4FKED
19 1 R8 RES., CHIP, 24.9kΩ, 1/16W, 1%, 0402 VISHAY, CRCW040224K9FKED
20 1 R9 RES., CHIP, 75kΩ, 1/16W, 1%, 0402 VISHAY, CRCW040275K0FKED
21 2 R10, R11 RES., CHIP, 100kΩ, 1/16W, 5%, 0402 VISHAY, CRCW0402100KJNED
22 3 SHUNTS AS
SHOWN ON ASSY
DWG
SHUNT, 2mm CTRS. SAMTEC, 2SN-BK-G
23 4 MH1-MH4 STAND-OFF, NYLON 0.25" KEYSTONE, 8831 (SNAP ON)
DC2161A-A Additional Demo Board Circuit Components
1 1 DC2161A-GENERAL BOM
2 1 U1 I.C., MICROPOWER HOT SWAP CONTROLLER, MS12 LINEAR TECH., LTC4231IMS-1
DC2161A-B Additional Demo Board Circuit Components
1 1 DC2161A-GENERAL BOM
2 1 U1 I.C., MICROPOWER HOT SWAP CONTROLLER, MS12 LINEAR TECH., LTC4231IMS-2

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DEMO MANUAL DC2161A
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 representa-
tion that the interconnection of its circuits as described herein will not infringe on existing patent rights.
SCHEMATIC DIAGRAM
5 5
4 4
3 3
2 2
1 1
D D C C B B A A
NOTE: UNLESS OTHERWISE SPECIFIED 1. ALL CAPACITORS ARE IN MICROFARADS, 0402. 2. ALL RESISTORS ARE IN OHM, 0402.
B
ASSY
A
U1
LTC4231-1 LTC4231-2
*SUFFIX
1 2
*
ON EXT OFF
IN
GATE
SOURCE
OUTSENSE
REVISION HISTORY DESCRIPTION DATEAPPROVEDECO REV
BOB S.PRODUCTION2 08-06-14
__
REVISION HISTORY DESCRIPTION DATEAPPROVEDECO REV
BOB S.PRODUCTION2 08-06-14
__
REVISION HISTORY DESCRIPTION DATEAPPROVEDECO REV
BOB S.PRODUCTION2 08-06-14
__
SIZE DATE:
IC NO. REV.
SHEET OF
TITLE:
APPROVALS
PCB DES.
APP ENG.
TECHNOLOGY Fax: [phone]
Milpitas, CA 95035 Phone: [phone] McCarthy Blvd. LTC Confidential-For Customer Use Only
CUSTOMER NOTICE
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. THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SCHEMATIC
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
SCALE = NONE
www.linear.com
2
Wednesday, August 06, 2014
11
MICROPOWER HOT SWAP CONTROLLER
KIM T.
BOB S.
N/A
LTC4231IMS-1/ 2
DEMO CIRCUIT 2161A
SIZE DATE:
IC NO. REV.
SHEET OF
TITLE:
APPROVALS
PCB DES.
APP ENG.
TECHNOLOGY Fax: [phone]
Milpitas, CA 95035 Phone: [phone] McCarthy Blvd. LTC Confidential-For Customer Use Only
CUSTOMER NOTICE
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. THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SCHEMATIC
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
SCALE = NONE
www.linear.com
2
Wednesday, August 06, 2014
11
MICROPOWER HOT SWAP CONTROLLER
KIM T.
BOB S.
N/A
LTC4231IMS-1/ 2
DEMO CIRCUIT 2161A
SIZE DATE:
IC NO. REV.
SHEET OF
TITLE:
APPROVALS
PCB DES.
APP ENG.
TECHNOLOGY Fax: [phone]
Milpitas, CA 95035 Phone: [phone] McCarthy Blvd. LTC Confidential-For Customer Use Only
CUSTOMER NOTICE
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. THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SCHEMATIC
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
SCALE = NONE
www.linear.com
2
Wednesday, August 06, 2014
11
MICROPOWER HOT SWAP CONTROLLER
KIM T.
BOB S.
N/A
LTC4231IMS-1/ 2
DEMO CIRCUIT 2161A
R7 8.45k R7 8.45k
C1 0.1uF 0603 C1 0.1uF 0603
E5
STATUS
E5
STATUS
U1
LTC4231
U1
LTC4231
IN
2
ON
3
GND
8
GNDSW
7
STATUS 9
SOURCE 11
SENSE 1
UVL
4
GATE 12
UVH
5
OV
6TIMER 10
R6 1.24M 0805 R6 1.24M 0805
E9
ON
E9
ON
R2 0.015 1206 1/4W R2 0.015 1206 1/4W
E6
GND
E6
GND
E10
TIMER
E10
TIMER
C2 OPT C2 OPT
R3 10 R3 10
E8
GND
E8
GND
R8 23.7k R8 23.7k
JP1
UV/OV
ENABLE
DISABLE
HD1X3-079
JP1
UV/OV
ENABLE
DISABLE
HD1X3-079
1 3 2
R5 12.1k 0603 R5 12.1k 0603
R9 66.5k R9 66.5k
Q1A
Si7960DP
Q1A
Si7960DP
2
7 81
J2
GND
J2
GND
E1E1
R10 100k R10 100k
E2E2
J1
VIN
12V
J1
VIN
12V
Q1B
Si7960DP
Q1B
Si7960DP
4
5 6
3
JP2 IQ
NORMAL MEASURE IQ
JP2 IQ
NORMAL MEASURE IQ
1
3
2
D1
SMBJ24CA
D1
SMBJ24CA
1 2
R4 OPT R4 OPT D2
GREEN
D2
GREEN
2 1
C4 0.082uF C4 0.082uF
J4
GND
J4
GND
E4E4
R11 100k R11 100k
R1 10 0603 R1 10 0603
J3
VOUT
12V, 3A
J3
VOUT
12V, 3A
E3E3
JP3
HD2X3-079
ENABLE
JP3
HD2X3-079
ENABLE
1 3 5 6
4 2
E7
IQ
E7
IQ
+
C3 100uF 25V 7343
+
C3 100uF 25V 7343

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DEMO MANUAL DC2161A
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
[phone] ●FAX: [phone] ●www.linear.com
 LINEAR TECHNOLOGY CORPORATION 2014
LT 1114 • PRINTED IN USA
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
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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
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