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dc1886bfa
DEMO MANUAL DC1886B
DESCRIPTION
LTC4232 and LTC4232-1:
5A Integrated
Hot Swap Controller
Demonstration circuit 1886B features the LTC4232 and
the LTC4232-1 5A integrated Hot Swap™ controllers. The
LTC4232 is ideally suited for demanding power distribution
control in 2.9V to 15V applications for hot board inser-
tion protection, high side power switching, and electronic
circuit breaker functions. The LTC4232 provides a rich set
of features to support Hot Swap applications including:
• 2% accurate undervoltage and overvoltage comparators
• Thermal protection
• Adjustable inrush current control
• Adjustable, 10% accurate current limit with program-
mable cutout time
• Foldback current limiting
• Programmable output voltage ramp rate
• Configurable auto-retry or latchoff on overcurrent faults
• Power good and fault outputs
• Debounce time during supply turn-on
PERFORMANCE SUMMARY
The LTC4232 debounce time is 100ms, while the LTC4232-1
is 16ms. Both are available in a 16-lead 5mm × 3mm DFN
package. The LTC4232 is showcased on demonstration
circuit 1886B-A. The LTC4232-1 is installed on DC1886B-B.
Both demo boards are configured for 12V application. By
changing a few passive components, 2.9V to 15V applica-
tions can be easily evaluated.
The LTC4232 has limited output voltage slew rate with
a typical value of 300V/s, while the LTC4232-1 does not
have a special circuit to limit this parameter. The natural
(maximum) gate voltage slew rate (SN) of the LTC4232-1
is defined by the internal MOSFET CRSS (reverse transfer
capacitance) value and gate driver current capability. It is
48000V/s as a typical value.
Design files for this circuit board are available at
http://www.linear.com/demo/DC1886B
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.
(TA = 25°C)
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
VDD Board Input Supply Range Min Is UV, Max Is OV 9.2 12 15.1 V
dVGATE/dt GATE Pin Turn-On Ramp Rate LTC4232
LTC4232-1 with 10nF GATE Capacitor
0.15
1.7
0.3
2.4
0.55
3.5
V/ms
V/ms
RON MOSFET + Sense Resistor On-Resistance 15 33 50 mΩ
ILIM(TH) Current Limit Threshold VFB = 1.23V, No RSET
VFB = 0V
VFB = 1.23V, RSET = 20k
5.0
1.2
2.6
5.6
1.5
2.9
6.1
1.8
3.3
A
A
A
VTH OV, UV, FB Pin Threshold Voltage VIN Rising 1.21 1.235 1.26 V
VUV(RTH) UV Pin Reset Threshold Voltage VUV Falling 0.55 0.62 0.7 V
VFB(HYST) FB Pin Power Good Hysteresis 10 20 30 mV
tD(AUTO-RETRY) Auto-Retry Turn-On Delay (Internal) LTC4232
LTC4232-1
50
8
100
16
150
24
ms
ms
TADJUST Timer Period for ADJUSTABLE Option LTC4232
LTC4232-1
9.5
0.95
12.3
1.23
16.8
1.68
ms
ms
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dc1886bfa
DEMO MANUAL DC1886B
JUMPERS AND LEDS
Figure 1. Proper Measurement Equipment Setup
Two demo board jumpers, JP1 and JP2, allow selection
of controller operation:
• JP1 TIMER DURATION: Set to FIXED 2ms position for
the internal 2ms timer period (FIXED 2ms not recom-
mended for LTC4232-1 during auto-retry) or ADJUST-
ABLE determined by TIMER capacitor C1 (12ms for
LTC4232 and 1.2ms for LTC4232-1). (Default position:
ADJUSTABLE)
• JP2 AUTORETRY: Set to ON for auto-retry or OFF for
latchoff on overcurrent fault. (Default position: OFF)
When selecting AUTORETRY option for the circuit with a
predominantly resistive load, particularly for LTC4232-1,
pay special attention to the power MOSFET thermal con-
dition. The initial low current limit (due to the foldback
characteristic) can power the load only during a very short
time, and the MOSFET will experience the maximum cur-
rent limit for almost all of the remaining power up period.
This may exceed the MOSFET SOA, if allowed to autoretry.
Four LEDs indicate the state of the hot swap circuit. Red
LEDs, D3 and D5, provide fault status and low output
voltage (it is a NOT power good signal). Two green LEDs,
D2 and D4, signal the presence of valid input and output
voltages.
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dc1886bfa
DEMO MANUAL DC1886B
QUICK START PROCEDURE
Demonstration circuit 1886B is easy to set up to evaluate
the performance of the LTC4232 or LTC4232-1. Refer to
Figure 1 for the proper measurement equipment setup
and follow the procedure below.
1. Place jumpers in the following positions:
JP1 TIMER DURATION FIXED 2ms
JP2 AUTORETRY OFF
2. With power off, connect 12V power supply terminals
to the VDD (E1) and GND (E3) turrets.
3. Turn on the 12V power supply and verify the output
voltage between the VOUT (E2) and GND (E4) turrets.
Two green LEDs, D2 and D4 should light up.
4. Check the current limit using an electronic or resis-
tive load. It should be in the range of 5A to 6.1A if an
overcurrent condition occurs while the output is high
(after powering up properly). If the output is shorted
initially, the load current will be limited in the range of
1.2A to 1.8A due to the foldback characteristic. Current
may be monitored on the IMON turret. The IMON signal
scale is 0.4V/A.
An overcurrent condition is indicated by the red LED
FLT(D3) and red LED PG (D5).
5. Check the output voltage slew rate with an oscilloscope,
without a load connected. It should take from 22ms
to 80ms for LTC4232, and from 3.0ms to 7.0ms for
LTC4232-1.
6. For DC1886B-A (LTC4232) use a 2000μF capacitive
load to demonstrate that power up mode completes
successfully. Use a current probe to verify that inrush
current is limited initially by the foldback characteristic
and later by the low output voltage slew rate.
7. For DC1886B-A use a 6000μF capacitive load to dem-
onstrate that the part not only enters into the current
limit state but operates in this state until the timer period
expires. It is not a successful power up.
8. For DC18886B-B use a 800μF capacitive load to demon-
strate a successful power up mode. The controller will
operate in current limit almost all of the timer period.
9. For DC1886B-B use a 3000μF capacitive load to
demonstrate an unsuccessful power up transient. The
operating point does not leave current limit during the
whole timer period. It will then time out and turn off.
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dc1886bfa
DEMO MANUAL DC1886B
PARTS LIST
ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER
Required Circuit Components
1 0 CIN1, COUT2 CAP., SANYO\16X25\H OPT
2 1 COUT1 CAP., TANT, 22µF 25V, 20%, 7343 AVX, TPSD226M025R0200
3 1 C2 CAP., X5R, 1µF 25V, 0603 AVX, 06033D105KAT2A
4 1 D1 DIODE, 400W TRANSIENT VOLTAGE
SUPPRESSOR, SMA-DIODE
DIODES INC., SMAJ22A-13-F
5 2 D2, D4 LED, GREEN, LED-ROHM-SML-010FT ROHM, SML-010FTT86L
6 2 D3, D5 LED, RED, LED-ROHM-SML-010VT ROHM, SML-010VTT86L
7 4 E1, E2, E3, E4 TURRET, TEST PIN, 0.094" MILL-MAX, 2501-2-00-80-00-00-07-0
8 8 E5-E12 TURRET, TEST PIN, 0.064" MILL-MAX, 2308-2-00-80-00-00-07-0
9 2 JP1, JP2 JMP, HD1X3, 0.079CC SULLIN, NRPN031PAEN-RC
10 1 RMON RES., CHIP, 20k, 1/8W, 5%, 0805 YAGEO, RC0805JR-0720KL
11 0 RSET RES., CHIP, 0805 OPT
12 4 R1, R2, R3, R5 RES., CHIP, 3.3k, 1/16W, 5%, 0603 YAGEO, RC0603JR-073K3L
13 1 R4 RES., CHIP, 150k, 1/16W, 5%, 0603 YAGEO, RC0603JR-07150KL
14 3 R6, R7, R8 RES., CHIP, 20k, 1/16W, 5%, 0603 YAGEO, RC0603JR-0720KL
15 1 R9 RES., CHIP, 140k, 1/16W, 5%, 0603 YAGEO, RC0603JR-07140KL
16 1 R10 RES., CHIP, 226k, 1/16W, 5%, 0603 YAGEO, RC0603JR-07226KL
17 2 SHUNT, 0.079" CENTER SAMTEC, 2SN-BK-G
DC1886B-A Required Circuit Components
1 DC1886B-GENERAL BOM
1 C1 CAP., X5R, 1µF 25V, 0603 AVX, 06033D105KAT2A
0 CGS, CGATE CAP., 0603 OPT
0 RGATE RES., 0603 OPT
1 U1 I.C., LTC4232IDHC, DFN16DHC LINEAR TECH., LTC4232IDHC
DC1886B-B Required Circuit Components
1 DC1886B-GENERAL BOM
1 C1 CAP., X5R, 0.1µF 25V, 0603 AVX, 06033D104KAT2A
0 CGS CAP., X7R, 3300pF 100V, 5%, 0603 AVX, 06031C332JAT2A
1 CGATE CAP., X7R, 0.01µF 100V, 5%, 0603 AVX, 06031C103JAT2A
1 RGATE RES., CHIP, 100k, 1/10W, 1% 0603 NIC, NRC06F1003TRF
1 U1 I.C., LTC4232IDHC-1, DFN16DHC LINEAR TECH., LTC4232IDHC-1
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dc1886bfa
DEMO MANUAL DC1886B
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
ALL CAPACITORS ARE IN MICROFARADS, 0603.
NOTES: UNLESS OTHERWISE SPECIFIED
2. INSTALL SHUNTS AS SHOWN.
1. ALL RESISTORS ARE IN OHMS, 0402.
FIXED ADJUSTABLE
TIMER
OFF ON
AUTORETRY
DURATION
CGATE
OPT
0.01uF
ASSY U1
*ALTC4232IDHC
LTC4232IDHC - 1B 100k
OPT
RGATESUFFIX
1
CGSC1
1uF
0.1uF
OPT
0.033uF
VOUT
VDD
SIZE
DATE:
IC NO. REV.
SHEET OF
TITLE:
APPROVALS
PCB DES.
APP ENG.
TECHNOLOGY Fax: (408)434-0507
Milpitas, CA 95035
Phone: (408)432-1900
1630 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
LTC4232IDHC / -1
06/06/2014, 04:50 PM 1 1
5A INTEGRATED HOT SWAP CONTROLLER
KIM T.
VLADIMIR O.
N/A
DEMO CIRCUIT 1886B
SIZE
DATE:
IC NO. REV.
SHEET OF
TITLE:
APPROVALS
PCB DES.
APP ENG.
TECHNOLOGY Fax: (408)434-0507
Milpitas, CA 95035
Phone: (408)432-1900
1630 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
LTC4232IDHC / -1
06/06/2014, 04:50 PM 1 1
5A INTEGRATED HOT SWAP CONTROLLER
KIM T.
VLADIMIR O.
N/A
DEMO CIRCUIT 1886B
SIZE
DATE:
IC NO. REV.
SHEET OF
TITLE:
APPROVALS
PCB DES.
APP ENG.
TECHNOLOGY Fax: (408)434-0507
Milpitas, CA 95035
Phone: (408)432-1900
1630 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
LTC4232IDHC / -1
06/06/2014, 04:50 PM 1 1
5A INTEGRATED HOT SWAP CONTROLLER
KIM T.
VLADIMIR O.
N/A
DEMO CIRCUIT 1886B
REVISION HISTORY
DESCRIPTION DATEAPPROVEDECO REV
VLADIMIR O.
REBUILD WITH CHANGE2 06-06-14
_
REVISION HISTORY
DESCRIPTION DATEAPPROVEDECO REV
VLADIMIR O.
REBUILD WITH CHANGE2 06-06-14
_
REVISION HISTORY
DESCRIPTION DATEAPPROVEDECO REV
VLADIMIR O.
REBUILD WITH CHANGE2 06-06-14
_
RSET
OPT
0805
RSET
OPT
0805
R10
226k
R10
226k
R1
3.3k
R1
3.3k
E10
ISET
E10
ISET
E3
GND
E3
GND R3
3.3k
R3
3.3k
D3
RED
D3
RED
2 1
R4
150k
R4
150k
E5
UV
E5
UV
+
COUT2
OPT
+
COUT2
OPT
C2
1uF
25V
C2
1uF
25V
JP1JP1
1
2
3
CGATE
*
CGATE
*
R7
20k
R7
20k
U1 *
U1 *
OV
3
FLT
12
UV
2
IMON 14
VDD
1
TIMER
4
INTVCC
5
ISET 15
PG 11
GATE 10
FB 13
OUT 9
GND
6
VDD
16 OUT 8
OUT 7
SENSE
17
JP2JP2
1
2
3
R6
20k
R6
20k
E7
FLT
E7
FLT
RMON
20k
0805
RMON
20k
0805
R2
3.3k
R2
3.3k
+
CIN1
OPT
+
CIN1
OPT
D4
GREEN
D4
GREEN
2 1
E12
INTVCC
E12
INTVCC
D5
RED
D5
RED
2 1
D1
SMAJ22A
D1
SMAJ22A
2 1
R5
3.3k
R5
3.3k
E8
PG
E8
PG
E1
VDD
12V
E1
VDD
12V
E11
IMON
E11
IMON
C1
*
C1
*
R8
20k
R8
20k
R9
140k
R9
140k
D2
GREEN
D2
GREEN
2 1
RGATE
*
RGATE
*
E9
TIMER
E9
TIMER
E6
OV E6
OV
E4
GND
E4
GND
E2 VOUT
12V / 5A
E2 VOUT
12V / 5A
+
COUT1
22uF
25V
7343
+
COUT1
22uF
25V
7343
CGS
*
CGS
*
6
dc1886bfa
DEMO MANUAL DC1886B
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com
LINEAR TECHNOLOGY CORPORATION 2012
LT 0814 REV A • 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
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 applica-
tion engineer.
Mailing Address:
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1630 McCarthy Blvd.
Milpitas, CA 95035
Copyright © 2004, Linear Technology Corporation
