1
dc1052af
DEMO MANUAL DC1052A
Description
LTC4218
Hot Swap Controller
Demonstration circuit DC1052A includes two separate
circuits for performance evaluation of the LT C
®
4218 Hot
Swap™ controller. The standard version of the control-
ler (LTC4218) is intended to operate with 2.9V to 26.5V
rails, while the LTC4218-12 has internal adjustment for
12V applications.
One circuit of DC1052A located on the upper board area
is assembled with the LTC4218 configured for operation
with a 24V rail. The circuit on the lower board area includes
the LTC4218-12. Circuit breaker thresholds in both cases
are adjusted to 7.5A.
The LTC4218 features accurate current limiting with fold-
back and a ground-referred current monitor. The current
monitor sources a current that is proportional to the sense
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.
performance summary
voltage, and it may be converted into a voltage signal with
an appropriate resistor.
The current limit may be reduced by placing an external
resistor between GND and the ISET pin.
The LTC4218 protects the load from overvoltage and
undervoltage conditions.
The DC1052A schematic allows the LTC4218 to operate in
turn-on and turn-off modes as well as in the steady-state
mode with different loads, and in the fault state.
Design files for this circuit board are available at
http://www.linear.com/demo
Specifications are at TA = 25°C
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
24V Circuit
VDD Input Supply Range Typical Value 19.89 24 26.34 V
VDD(UVL) Input Supply Undervoltage Range VDD Rising 19.32 19.89 20.68 V
VDD(OVH) Input Supply Overvoltage Range VDD Rising 25.56 26.34 27.39 V
VOUT(PG) Output Voltage Defined as Power Good VSOURCE Rising 20.00 20.75 21.57 V
tTIMER Timer Period 0.9 1.235 1.76 ms
ILIMIT Current Limit VFB = 1.23V (VOUT in the Range 20.33V to 21.16V)
VFB = 0V to 0.15V (VOUT in the Range 0V to 2.6V)
7.05
1.38
7.5
1.88
7.95
2.37
A
A
CMAX24 Maximal Load Capacitance Successful Power-Up Mode 600 μF
CMIN24 Minimal Load Capacitance Unsuccessful Power-Up Mode 1800 μF
12V Circuit
VDD Input Supply Range Typical Value 9.88 12 15.05 V
VDD(UVL) Input Supply Undervoltage Range VDD Rising 9.6 9.88 10.2 V
VDD(OVH) Input Supply Overvoltage Range VDD Rising 14.7 15.05 15.4 V
VOUT(PG) Output Voltage Defined as Power Good VSOURCE Rising 10.2 10.5 10.8 V
tTIMER Timer Period 0.9 1.235 1.76 ms
ILIMIT Current Limit VFB = 1.23V (VOUT in the Range 10.3V to 10.4V)
VFB = 0V to 0.15V (VOUT in the Range 0V to 1.27V)
7.05
1.38
7.5
1.88
7.95
2.37
A
A
CMAX12 Maximal Load Capacitance Successful Power-Up Mode 900 μF
CMIN12 Minimal Load Capacitance Unsuccessful Power-Up Mode 1800 μF
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dc1052af
DEMO MANUAL DC1052A
operating principles
The LTC4218 is suited for low voltage power control in
applications for hot board insertion or removal with elec-
tronic circuit breaker function, foldback current limit and
load current monitoring. The LTC4218 has a rich set of
features to support Hot Swap applications, including:
• 2%accurate undervoltage and overvoltage protection
• Adjustable5%accurate current limit
• Adjustable inrush current control
• Load current monitoring
• Adjustable current limit timer before power is turned
off
• Power good and fault signaling
Quick start proceDure
Demonstration circuit 1052A is easy to set up to evaluate
the performance of the LTC4218 and LTC4218-12. Refer
to Figure 1 for the proper measurement equipment setup
and follow the procedure below.
For the 24V circuit:
1. Place jumpers in the following positions:
JP1 FAULT Signal
JP2 AUX_UV ON
2. With power off, connect the 24V power supply terminals
to the 24VIN (E1) and GND (E4) turrets.
3. Turn on the 24V supply and verify the output voltage
between the VOUT (E2) and GND (E3) turrets. Green
LEDs 24VIN (D2) and VOUT (D4) should light up.
4. Check the current limit by providing an electronic or
resistive load. It should be in the range of 7.05A to
7.95A. During this measurement, verify the current
monitor performance. The monitor signal related to
the current limit level should be 2.0V ± 0.17V. The
monitor signal has a 3.75A/V scale.
5. Use an oscilloscope to check the output voltage slew
rate without a load connected. It should be in the range
of 1680V/s to 2300V/s. Use an 1800μF capacitive load
to confirm that during power-up, the timer period
expires and a current limit fault is indicated by the
FAULT red LED (D5). The PG red LED (D6) indicates
that the output voltage is lower than the power good
level.
For the 12V circuit:
6. Place jumpers in the following positions:
JP3 FAULT Signal
JP4 AUX_UV ON
7. With power off, connect the 12V power supply terminals
to the 12VIN (E9) and GND (E12) turrets.
8. Turn on the 12V supply and verify the output voltage
at the VOUT (E10) and GND (E11) turrets. Green LEDs
12VIN (D9) and VOUT (D11) should light up.
9. Check the current limit by providing an electronic or
resistive load. It should be in the range of 7.05A to
7.95A. During this measurement verify the current
monitor performance. The monitor signal related to
the current limit level should be 2.0V ± 0.17V. The
monitor signal has a 3.75A/V scale.
10. Check the output voltage slew rate with an oscilloscope
without a load connected. It should be in the range of
1680V/s to 2300V/s.
11. Use an 1800µF capacitive load to confirm that during
power-up the timer period expires and a current limit
fault is indicated by the FAULT red LED (D12) accom-
panied by the PG red LED (D13) to indicate that the
output voltage is lower than the power good level.
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dc1052af
DEMO MANUAL DC1052A
Quick start proceDure
Figure 1. Proper Measurement Equipment Setup
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dc1052af
DEMO MANUAL DC1052A
parts list
ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER
1 4 C1, C2, C4, C6 CAP., CER X7R 0.1µF 16V 0603 AVX 0603YC104KAT2A
2 2 C3, C5 CAP., CER X7R 0.01µF 50V 0603 AVX 06035C103KAT2A
3 0 COUT1, COUT2 OPTIONAL
4 0 CIN1, CIN2 OPTIONAL
5 8 E5-E8, E13-E16 TURRET, TEST PIN, .061" MILL-MAX 2308-2-00-44
6 8 E1-E4, E9-E12 TURRET, TEST PIN, .095" MILL-MAX 2501-2
7 4 JP1-JP4 JUMPER, 0.079, 3 PIN SAMTEC, TMM-103-02-L-S
8 4 JP1-JP4 SHUNT, SAMTEC, 2SN-BK-G
9 4 D5, D6, D12, D13 LED, SMT RED PANASONIC, LN1251C
10 4 D2, D4, D9, D11 LED, SMT GREEN PANASONIC, LN1351C
11 1 D1 DIODE, 600W TRANSIENT VOLTAGE SUPPRESSOR DIODES INC., SMBJ24A
12 1 D8 DIODE, 600W TRANSIENT VOLTAGE SUPPRESSOR DIODES INC., SMBJ12A
13 0 D3, D10, D17, D14 OPTIONAL SMA
14 2 Q1, Q2 MOSFET N-CHANNEL 30V, POWER PAK-SO-8 VISHAY, Si7880ADP
15 2 R1, R13 RES., CHIP, 0.002Ω 1/4W1%1206 VISHAY, WSL12062L000FEA
16 2 R8, R18 RES., CHIP, 10Ω 1/16W5%0603 VISHAY, CRCW060310R0JNEA
17 2 R11, R19 RES., CHIP, 1k 1/16W5%0603 VISHAY, CRCW06031K00JNEA
18 1 R10 RES., CHIP, 3.24k 1/16W1%0603 Vishay, CRCW06033K24FKEA
19 4 R14-R17 RES., CHIP, 3.30k 1/16W5%0603 VISHAY, CRCW06033K30JNEA
20 4 R2, R4, R5, R6 RES., CHIP, 6.80k 1/4W5%1206 VISHAY, CRCW12066K80JNEA
21 2 R9, R12 RES., CHIP, 10k 1/16W1%0603 VISHAY, CRCW060310K0FKEA
22 2 RMON1, RMON2 RES., CHIP, 20k 1/16W5%0805 VISHAY, CRCW080520K0JNEA
23 1 R7 RES., CHIP, 158k 1/16W1%0603 VISHAY, CRCW0603158KFKEA
24 1 R3 RES., CHIP, 200k 1/16W1%0603 VISHAY, CRCW0603200KFKEA
25 0 RSET1, RSET2 OPTIONAL
26 1 U1 IC., HOT SWAP CONTROLLER LINEAR, LTC4218CGN
27 1 U2 IC., HOT SWAP CONTROLLER LINEAR, LTC4218CDHC-12
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dc1052af
DEMO MANUAL DC1052A
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
1
1
2
2
3
3
4
4
5
5
6
6
7
7
8
8
A A
B B
C C
D D
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
Supplied For Use With Linear Technology Parts.
LTC CONFIDENTIAL - FOR CUSTOMER USE ONLY
PG
PG
1206
1206
1206
Auto-Retry
FAULT
Signal
Auto-Retry
FAULT
Signal
1206
FAULT
Future Use
Table
U1ASSEMBLY
DC1052A-A LTC4218CGN
DC1052A-B
U2
LTC4218CDHC-12
Future Use
Alternate Part For Q1
SUM110MO3-03P
VOUT
VOUT
FAULT
ON
AUX_UV
OFF
ON
AUX_UV
OFF
POSITIVE 24V HOT SWAP
POSITIVE 12V HOT SWAP
LTC4218CGN, LTC4218CDHC-12
Demo Circuit 1052A-A/B
Positive 24V, Positive 12V Hot Swap
LINEAR TECHNOLOGY CORPORATION
1630 McCARTHY BLVD.
MILPITAS, CA. 95035
PHONE (408) 954-8400 FAX (408) 434-0507
11
Tuesday, February 05, 2008
Demo Circuit 1052A-A/B
Positive 24V, Positive 12V Hot Swap
LINEAR TECHNOLOGY CORPORATION
1630 McCARTHY BLVD.
MILPITAS, CA. 95035
PHONE (408) 954-8400 FAX (408) 434-0507
11
Tuesday, February 05, 2008
Demo Circuit 1052A-A/B
Positive 24V, Positive 12V Hot Swap
LINEAR TECHNOLOGY CORPORATION
1630 McCARTHY BLVD.
MILPITAS, CA. 95035
PHONE (408) 954-8400 FAX (408) 434-0507
11
Tuesday, February 05, 2008
R13
.002
R13
.002
D9
LED
(GRN)
D9
LED
(GRN)
2 1
D3
(Opt.)
D3
(Opt.)
2 1
R9
10K
1%
R9
10K
1%
E5
FAULT Output
E5
FAULT Output
E9
12VIN
E9
12VIN
JP3JP3
1
2
3
D14
(Opt.)
D14
(Opt.)
21
C2
0.1uF
16V
C2
0.1uF
16V
E16
ISET
E16
ISET
D4
LED
(GRN)
D4
LED
(GRN)
2 1
D13
LED
(RED)
D13
LED
(RED)
2 1
R11
1K
R11
1K
R6
6.8K
R6
6.8K
R17
3.3K
R17
3.3K
E11
GND
E11
GND
E14
PG
E14
PG
JP2JP2
1
2
3
E2
24V/7.5A
E2
24V/7.5A
E3
GND
E3
GND
E12
GND
E12
GND
E7
IMON
E7
IMON
RMON2
20K
1%
RMON2
20K
1%
E6
PG
E6
PG
R15
3.3K
R15
3.3K
D12
LED
(RED)
D12
LED
(RED)
2 1
E10
12V/7.5A
E10
12V/7.5A
D8
SMBJ12A
D8
SMBJ12A
2 1
R16
3.3K
R16
3.3K
JP4JP4
1
2
3
R8
10
R8
10
RSET1
(Opt.)
RSET1
(Opt.)
R7
158K
1%
R7
158K
1%
E8
ISET
E8
ISET
D5
LED
(RED)
D5
LED
(RED)
2 1
D7
(Opt.)
D7
(Opt.)
21
R10
3.24K
1%
R10
3.24K
1%
R5
6.8K
R5
6.8K
R3
200K
1%
R3
200K
1%
+
CIN2
(Opt.)
+
CIN2
(Opt.)
R19
1K
R19
1K
R12
10K
1%
R12
10K
1%
D10
(Opt.)
D10
(Opt.)
2 1
C4
0.1uF
16V
C4
0.1uF
16V
R2
6.8K
R2
6.8K
D1
SMBJ24A
D1
SMBJ24A
2 1
RSET2
(Opt.)
RSET2
(Opt.)
RMON1
20K
1%
RMON1
20K
1%
R4
6.8K
R4
6.8K
R14
3.3K
R14
3.3K
U1
LTC4218CGN
U1
LTC4218CGN
UV
3
OV
4
VDD
2
GND
7
NC
1
TIMER
5
INTVCC
6
SOURCE
8GATE 9
PG 10
FAULT 11
FB 12
IMON 13
ISET 14
SENSE- 15
SENSE+ 16
JP1JP1
1
2
3
E1
24VIN
E1
24VIN
D2
LED
(GRN)
D2
LED
(GRN)
2 1
R18
10
R18
10
E13
FAULT Output
E13
FAULT Output
C6
0.1uF
16V
C6
0.1uF
16V
C3
0.01uF
C3
0.01uF
E15
IMON
E15
IMON
D6
LED
(RED)
D6
LED
(RED)
2 1
C5
0.01uF
C5
0.01uF
+
CIN1
(Opt.)
+
CIN1
(Opt.)
C1
0.1uF
16V
C1
0.1uF
16V
D11
LED
(GRN)
D11
LED
(GRN)
2 1
Q2
Si7880ADP
Q2
Si7880ADP
3
1
2
4
5
6
7
8
R1
.002
R1
.002
COUT2
(Opt.)
COUT2
(Opt.)
E4
GND
E4
GND
Q1
Si7880ADP
Q1
Si7880ADP
3
1
2
4
5
6
7
8
COUT1
(Opt.)
COUT1
(Opt.)
U2
LTC4218CDHC-12
U2
LTC4218CDHC-12
UV
3
OV
4
VDD
2
GND
7
NC
1
TIMER
5
INTVCC
6
SOURCE
8GATE 9
PG 10
FAULT 11
FB 12
IMON 13
ISET 14
SENSE- 15
SENSE+ 16
6
dc1052af
DEMO MANUAL DC1052A
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com
LINEAR TECHNOLOGY CORPORATION 2013
LT 0513 • PRINTED IN USA
DEMONSTRATION BOARD IMPORTANT NOTICE
Linear Technology Corporation (LT C ) 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 LT C 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. LT C assumes no liability for applications assistance,
customer product design, software performance, or infringement of patents or any other intellectual property rights of any kind.
LT C 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 LT C applica-
tion engineer.
Mailing Address:
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1630 McCarthy Blvd.
Milpitas, CA 95035
Copyright © 2004, Linear Technology Corporation
