Linear Technology LTC4227-1 Quick setup guide

1
dc1625af
DEMO MANUAL DC1625A
Description
LTC4227-1/LTC4227-2
Dual Ideal Diode and
Single Hot Swap Controller
Demonstration circuit 1625A is intended to demonstrate
performance of the LTC4227-1/LTC4227-2 dual ideal diode
and Hot Swap™ controller. Each rail has an individual
ideal diode. Ideal diode outputs are connected to the load
through a single Hot Swap circuit.
The DC1625 allows verifying the LTC4227 Hot Swap and
ideal diode functionality during individual supply ramp-up
and ramp-down transients, during power supply shifting
(transferring) transients, steady state, and overcurrent
fault conditions.
Each DC1625A rail circuit is assembled to operate over
the full operating voltage range of the LTC4227: 2.9V to
18V, with a 7.6A maximum current load.
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
The board’s main components include the LTC4227 con-
troller, two power MOSFETs controlled as ideal diodes and
one power MOSFET controlled as a Hot Swap device, two
jumpers for enabling the second ideal diode (D2ON_SEL)
and Hot Swap controller (HS_ON), two LEDs to indicate
power good (PWRGD) and fault (FAULT) conditions, seven
banana jacks forconnecting power suppliesand load, many
turrets and pads for observing circuit signals.
Design files for this circuit board are available at
http://www.linear.com/demo
(TA= 25°C)
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
Supplies
VIN Input Supply Range 2.9 18.0 V
VINTVCC Internal Regulator Voltage 4.5 55.6 V
VINTVCC(UVL) Internal VCC Undervoltage Lockout INTVCC Rasing 2.1 2.2 2.3 V
Ideal Diode Control
ΔVFWD(REG) Forward Regulation Voltage (VINN – VSENSE)10 25 40 mV
ΔVDGATE External N-Channel Gate Drive
(VDGATEN - VINN)
IN < 7V, ΔVFWD = 0.1V
IN = 7V to 18V, ΔVFWD = 0.1V
5
10
7
12
14
14
V
V
ICPO(UP) CPONPull-Up Current CPO = IN = 2.9V
CPO = IN = 18V
60
50
95
85
120
110
µA
µA
IDGATE(FPU) DGATENFast Pull-Up Current ΔVFWD = 0.2V, ΔVDGATE = 0V, CPO = 17V 0 –1.5 A
IDGATE(FDU) DGATENFast Pull-Down Current ΔVFWD = –0.2V, ΔVDGATE = 5V 1.5 A
IDGATE2(DN) DGATE2 Off Pull-Down Current D2ON = 2V, ΔVDGATE2 = 2.5V 40 100 200 µA
tON(DGATE) DGATENTurn-On Delay ΔVFWD = 0.2V, CGATE = 10nF 0.25 0.5 µs
tOFF(DGATE) DGATENTurn-Off Delay ΔVFWD = –0.2V, CGATE = 10nF 0.2 0.5 µs
tPLH(DGATE2) D2ON Low to DGATE2 High 40 100 µs
Hot Swap Control
ΔVSENSE(CB) Circuit Breaker Trip Sense Voltage
(VSENSE+ - VSENSE–)
47.5 50 52.5 mV
ΔVSENSE(ACL) Active Current Limit Sense Voltage
(VSENSE+- VSENSE–)
60 65 70 mV
Downloaded from Arrow.com.

2
dc1625af
DEMO MANUAL DC1625A
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
ΔVHGATE External N-Channel Gate Drive (VHGATE - VOUT) IN < 7V, I = 0, –1μA
IN = 7V to 18V, I = 0, –1μA
4.8
10
7
12
14
14
V
V
IGATE(UP) External N-Channel Gate Pull-Up Current Gate Drive On, HGATE = 0V 7 10 13 µA
IHGATE(DN) External N-Channel Gate Pull-Down Current Gate Drive Off, OUT = 12V, HGATE = OUT + 5V 150 300 500 µA
IHGATE(FPD) External N-Channel Gate Fast Pull-Down
Current
Fast Turn-Off, OUT = 12V, HGATE = OUT + 5V 100 200 300 mA
Input/Output Pin
VSENSE+(UVL) SENSE+Undervoltage Lockout SENSE+Rising 1.75 1.9 2.05 V
VON(TH) ON Pin Threshold Voltage ON Rising 1.21 1.235 1.26 V
VON(RESET) ON Pin Fault Reset Threshold Voltage ON Falling 0.55 0.6 0.65 V
VD2ON(TH) D2ON Pin Threshold Voltage D2ON Rising 1.21 1.235 1.26 V
VTMR(TH) TMR Pin Threshold Voltage TMR Rising
TMR Falling
1.198
0.15
1.235
0.2
1.272
0.25
V
V
ITMR(UP) TMR Pull-Up Current TMR = 1V, In Fault Mode 75 100 125 µA
ITMR(DN) TMR Pull-Down Current TMR = 2V, No Faults 1.4 22.6 µA
ITMR(RATIO) TMR Current Ratio ITMR(DN)/ ITMR(UP) 1.4 22.7 %
perForMAnce sUMMArY
operAting principles
The LTC4227 is intended to build a combination of the
two diode-OR circuits (for two rails) and common single
Hot Swap path for inrush current limiting and overcurrent
protection.
The LTC4227 regulates the forward voltage drop across
the MOSFETs to ensure smooth current transfer from one
supply to other without oscillation. A fast turn-on reduces
the load voltage droop during supply switchover. If the
input supply fails or is shorted, a fast turn-off minimizes
reverse current transients.
The Hot Swap fast acting current limit and internal timed
circuit breaker protect circuit components when a short-
circuit fault occurs.
The Hot Swap function on the LTC4227 controller has
independent on/off control.
Each ideal diode MOSFET is activated from individual
charge pump sources and the second ideal diode path
has additional on/off control.
The LTC4227-1 features a latch-off circuit breaker, while
the LTC4227-2 provides automatic retry after a fault.
Downloaded from Arrow.com.Downloaded from Arrow.com.

3
dc1625af
DEMO MANUAL DC1625A
qUick stArt proceDUre
Demonstration circuit 1625A is easy to set up to evalu-
ate the performance of the LTC4227. Refer to Figure 1
for proper measurement equipment setup and follow the
procedure below:
The DC1625A testincludes independenttest ofthe LTC4227
hot swapping functionality and ideal diode functionality.
HOT SWAP FUNCTIONALITY TEST
This test is performed with singe rail operation, when
the rail output is provided through two series connected
MOSFETs. One MOSFET functions as an ideal diode and
other one as a Hot Swap circuit component.
The parameters of the three transients in different opera-
tion modes completely characterize the Hot Swap circuit
performance. These actions are:
- A power-up without any additional load
- A current limit operation after successful power-up
transient
- A power-up with shorted output
1. Initially, install the jumper heads in the following posi-
tions, if the first ideal diode is used in the test:
JP1 EN_SEL in the position LOW
JP2 D2ON_SEL in the position OFF
JP3 ON_SEL in the position OFF
If the second ideal diode is used:
JP1 EN_SEL in the position LOW
JP2 D2ON_SEL in the position ON
JP3 ON_SEL in the position OFF
Connect a 12V power supply to the board input turrets
IN1 (or IN2) and GND. Do not load the output. Place
the current probe on the 12V wire and voltage probes
on the OUT turret.
Provide ON signal at the ON pin by changing the JP3
jumper headerposition fromOFF positionto ON.Observe
the transient. The output voltage rise time should be
in the range of 12ms to 29ms. PWRGD green LED D3
(D5) must turn on. Turn off the rail using the ON jumper.
2. Connect a disabled electronic load to the OUT turret
and GND. Turn on the rail and slowly increase the load
current up to the circuit breaker threshold level. The
current limit range should be from 7.8A to 8.9A.
The DC1625A-A circuit features a latchoff circuit breaker,
and DC1625A-B provides automatic retry after a fault.
Turn off the rail with the ON_SEL jumper.
3. Initially short output with external wire. Place the current
probe at this external wire. Turn on the rail and record
the current shape. The maximum current should be in
the 10.1A to 11.8A range.
Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.

4
dc1625af
DEMO MANUAL DC1625A
IDEAL DIODE FUNCTIONALITY TEST
In this test, both ideal diodes are active and small varia-
tions in the input voltage forces one ideal diode to be off
and another ideal diode to be on.
Connect input turrets (IN1 and IN2) of each ideal diode
with individual independent lab supply. Adjust each input
voltage to 12V with maximum possible accuracy. Place
qUick stArt proceDUre
one voltmeter between IN1 and IN2 turrets to measure
the difference between two input voltages. Connect an
electronic load to the output turret. Activate both rail and
keep a load around 1A to 3A. Play with input voltage levels
and be sure that when the difference between input volt-
ages exceeds 40mV, only one rail feeds the load.
Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.

5
dc1625af
DEMO MANUAL DC1625A
qUick stArt proceDUre
Figure 1. Measurement Equipment Setup for the LTC4227 Test
SWITCH
DC1625A F01
POWER
SUPPLY 1
POWER
SUPPLY 2
LOAD
–
+
–
+
Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.

6
dc1625af
DEMO MANUAL DC1625A
pArts list
ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER
Required Circuit Components
1 8 C1, C2 ,C3, C4, C6,
C7, C10, C11
CAP, X7R, 0.1µF, 50V, 0603 TDK, C1608X7R1H104K
2 1 C5 CAP, X7R, 15nF, 50V, 0603 AVX, 06035C153KAT
3 0 C8, C9 OPT CAP, AL, El, S/M 100µF, 50V SUNCON, 50CE100BS
4 1 C12 CAP, AL, El, S/M 100µF, 50V SUNCON, 50CE100BS
5 0 C12 OPT CAP, AL, El, S/M 1000µF, 50V NIC, NACEW102M50V16X17TR13F
6 2 D1, D2 DIODE, VOLTAGE SUPPRESSOR, SMA DIODES, SMAJ17A-13-F
7 1 D3 LED, SMT GREEN PANASONIC, LN1351CTR
8 1 D4 LED, SMT RED PANASONIC, LN1261CTR
911 E1, E3, E6, E8, E9,
E12 to E17
TURRET, TESTPOINT, 2501 MILL-MAX, 2501-2-00-80-00-00-07-0
10 7 E2, E4, E5, E7, E10,
E11, E18
JACK BANANA KEYSTONE, 575-4
11 2E27, E28 TURRET, TESTPOINT, 2308 MILL-MAX, 2308-2-00-80-00-00-07-0
12 3JP1, JP2, JP3 HEADERS, 3 PINS 2mm CTRS SAMTEC TMM-103-02-L-S
13 3XJP1, XJP2, XJP3 SHUNT, 2mm CTRS SAMTEC 2SN-BK-G
14 2Q1, Q2 MOSFET, N-CHANNEL, 30-V VISHAY, SiR462DP-T1-GE3
15 1 Q3 MOSFET, N-CHANNEL, 30-V VISHAY, Si7336ADP-T1-GE3
16 1 RS1 RES, CHIP, 0.006, 1/2W, 1%, 2010 KOA, TLR2HDBK6L00F75
17 3 R1, R9, R10 RES, CHIP, 10, 1%, 0603 VISHAY, CRCW060310R0FKEA
18 1 R2 RES, CHIP, 47, 1%, 0603 VISHAY, CRCW060347R0FKEA
19 2 R3, R7 RES, CHIP, 20k, 1%, 0603 VISHAY, CRCW060320K0FKEA
20 1R4 RES, CHIP, 22.1k, 1%, 0603 VISHAY, CRCW060322K1FKEA
21 2 R5, R6 RES, CHIP, 3k, 1%, 0805 VISHAY, CRCW08053K00FKEA
22 1R8 RES, CHIP, 28.7k, 1%, 0603 VISHAY, CRCW060328K7FKEA
23 4STAND-OFF STAND-OFF, NYLON 0.5" KEYSTONE, 8833 (SNAP ON)
24 1STENCIL STENCIL 1625A
Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.

7
dc1625af
DEMO MANUAL DC1625A
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
OFF
LTC4227CUFD-2
OFF
*
ON
50V
DC1625A-B DC1625A-A
100uF
ASSY
(
ASSY TABLE
(
U1
LTC4227CUFD-1
2
Wednesday, May 12, 2010
11
DUAL IDEAL DIODE AND SINGLE HOT SWAP CONTROLLER
AK
VLAD O.
N/A
LTC4227CUFD-1/2
DEMO CIRCUIT 1625A
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
VLAD O.
PRODUCTION-2 05-12-10
REVISION HISTORY DESCRIPTION DATEAPPROVEDECO REV
ON_PIN
ON_PIN
IN1
OUT
IN2
IN1
TP21
E16
GND
E4
GND
E19
TP25
E12
ON
D1
SMAJ17A
2
1
E17
PROBE GND
D2
SMAJ17A
2
1
E2
IN1
2.9V to 18V
C3
0.1uF
50V
X7R
E14
EN
E1
IN1
E28
FAULT
E8
IN2
Q1
SiR462DP
4
5
1 3 2 6
7 8
C5
15nF 50V
TP23
E6
GND
E13
GND
+
C9
100uF
50V
OPT
12
C10
0.1uF
50V
E3
OUT
E18
SENSEP
R2
47
R8 28.7K
1%
JP1
LOW
EXT
EN_SEL
1 3
2
R6 3K
JP3
ON
HS_ON
1 3
2
C4
0.1uF
16V
X7R
U1
*
4
12 21
5
9
16
13 14 10 11 15
18
1
2
7
8
6
20
3
19
17
INTVcc D2ON EP GND
NC
NC
TMR
EN
PWRGD
FAULT
ON
HGATE
SENSEM
SENSEP
DGATE2
CPO2
IN2
DGATE1
IN1
CPO1
OUT
E27
PWRGD
E9
GND
RS1
0.006
0.5W
TP20
Q3 Si7336ADP
4
5
1 3 26
7 8
C6
0.1uF
50V
R5 3K
C7
0.1uF
50V
+
C12
1000uF
50V
OPT
12
R9
10
E5
OUT
7.6A
TP26
TP24
Q2
SiR462DP
4
5
1 3 2 6
7 8
JP2
D2ON_SEL
1 3 2
D3
GREEN
12
R1
10
TP22
D4
RED
12
R7
20K
1%
R10
10
E11
GND
E7 GND
C2
0.1uF
50V
X7R
E10
IN2
2.9V to 18V
C1
0.1uF
50V
X7R
E15
D2ON
+
C8
100uF
50V
OPT
12
R3 20K 1%
R4
22.1K
1%
C11
0.1uF 50V
Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.

8
dc1625af
DEMO MANUAL DC1625A
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
[phone] ●FAX: [phone] ●www.linear.com
 LINEAR TECHNOLOGY CORPORATION 2011
LT 0611 • 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:
Linear Technology
1630 McCarthy Blvd.
Milpitas, CA 95035
Copyright © 2004, Linear Technology Corporation
Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.