LTC4233
10A Guaranteed SOA
Hot Swap Controller
FEATURES
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DESCRIPTION
The
LTC
®
4233
is an integrated solution for Hot Swap™
applications that allows a board to be safely inserted and
removed from a live backplane. The part integrates a Hot
Swap controller, power MOSFET and current sense resis-
tor in a single package for small form factor applications.
The MOSFET Safe Operating Area is production tested
and guaranteed for the stresses in Hot Swap applications.
The LTC4233 provides separate inrush current control
and an 11% accurate 11.2A current limit with output
dependent foldback. The current limit threshold can be
adjusted dynamically using the I
SET
pin. Additional features
include a current monitor output that amplifies the sense
resistor voltage for ground referenced current sensing
and a MOSFET temperature monitor output. Thermal limit,
overvoltage, undervoltage and power good monitoring
are also provided. For a 20A pin compatible version see
LTC4234.
L,
LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and Hot
Swap and PowerPath are trademarks of Linear Technology Corporation. All other trademarks are
the property of their respective owners.
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Allows Safe Board Insertion into a Live Backplane
Small Footprint
10mΩ MOSFET Including R
SENSE
Safe Operating Area Guaranteed at 41W, 30ms
Wide Operating Voltage Range: 2.9V to 15V
Adjustable, 11% Accurate Current Limit
Current and Temperature Monitor Outputs
Overtemperature Protection
Adjustable Current Limit Timer Before Fault
Power Good and Fault Outputs
Adjustable Inrush Current Control
2.5% Accurate Undervoltage and Overvoltage
Protection
Available in 38-Lead (5mm × 9mm) QFN Package
Pin Compatible with LTC4234
APPLICATIONS
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High Availability Servers
Solid State Drives
Industrial
Network Routers and Switches
TYPICAL APPLICATION
12V, 10A Card Resident Application with Auto-Retry
V
OUT
12V
10A
680µF
Power-Up Waveforms
12V
*
107k
V
DD
LTC4233
UV
FLT
5.23k
OV
10k
SENSE
–
SENSE
TIMER
INTV
CC
1µF
GND
OUT
150k
FB
20k
10k
PG
GATE
I
SET
I
MON
20k
ADC
+
V
IN
10V/DIV
I
IN
0.2A/DIV
V
OUT
10V/DIV
PG
10V/DIV
CONTACT
BOUNCE
20ms/DIV
4233 TA01b
*TVS: DIODES INC. SMAJ17A
4233 TA01a
4233f
For more information
www.linear.com/LTC4233
1
LTC4233
ABSOLUTE MAXIMUM RATINGS
(Notes 1, 2)
PIN CONFIGURATION
TOP VIEW
OUT
OUT
OUT
OUT
WHH PACKAGE
38-LEAD PLASTIC QFN (5mm × 9mm)
T
JMAX
= 150°C,
θ
JA
= 15°C/W
EXPOSED PAD (PINS 39 AND 40) ARE VDD AND SENSE,
θ
JA
= 15°C/W SOLDERED, OTHERWISE
θ
JA
= 50°C/W
ORDER INFORMATION
LEAD FREE FINISH
LTC4233CWHH#PBF
LTC4233IWHH#PBF
LTC4233HWHH#PBF
TAPE AND REEL
LTC4233CWHH#TRPBF
LTC4233IWHH#TRPBF
LTC4233HWHH#TRPBF
PART MARKING
4233
4233
4233
PACKAGE DESCRIPTION
38-Lead (5mm × 9mm) Plastic QFN
38-Lead (5mm × 9mm) Plastic QFN
38-Lead (5mm × 9mm) Plastic QFN
TEMPERATURE RANGE
0°C to 70°C
–40°C to 85°C
–40°C to 125°C
Consult LTC Marketing for parts specified with wider operating temperature ranges.
Consult LTC Marketing for information on nonstandard lead based finish parts.
For more information on lead free part marking, go to:
http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to:
http://www.linear.com/tapeandreel/
OUT
OUT
Supply Voltage (V
DD
) ................................. –0.3V to 28V
Input Voltages
FB, OV, UV ..............................................–0.3V to 12V
TIMER ................................................... –0.3V to 3.5V
SENSE
–
, SENSE .....V
DD
− 10V or –0.3V to V
DD
+ 0.3V
Output Voltages
I
SET
, I
MON
................................................. –0.3V to 3V
PG,
FLT
................................................. –0.3V to 35V
OUT ............................................ –0.3V to V
DD
+ 0.3V
INTV
CC
.................................................. –0.3V to 3.5V
GATE (Note 3) ........................................ –0.3V to 33V
Operating Ambient Temperature Range
LTC4234C ................................................ 0°C to 70°C
LTC4234I .............................................–40°C to 85°C
LTC4234H .......................................... –40°C to 125°C
Junction Temperature (Note 4, 5) ......................... 150°C
Storage Temperature Range .................. –65°C to 150°C
UV
OV
I
MON
TIMER
INTV
CC
V
DD
(DNC)
GND
SENSE (DNC)
OUT
OUT
OUT
OUT
OUT
OUT
OUT
OUT
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
40
SENSE
39
V
DD
38
37
36
35
34
33
32
31
30
29
28
27
26
25
24
23
I
SET
FB
FLT
PG
SENSE
–
V
DD
(DNC)
GATE
SENSE
OUT
OUT
OUT
OUT
OUT
OUT
OUT
OUT
4233f
2
For more information
www.linear.com/LTC4233
LTC4233
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
DD
= 12V unless otherwise noted.
SYMBOL
V
DD
I
DD
V
DD(UVL)
I
OUT
dV
GATE
/dt
R
ON
I
LIM(TH)
PARAMETER
Input Supply Range
Input Supply Current
Input Supply Undervoltage Lockout
OUT Leakage Current
OUT Turn-on Ramp Rate
MOSFET + Sense Resistor
On-Resistance
Current Limit Threshold
MOSFET On, No Load
V
DD
Rising
V
OUT
= V
GATE
= 0V, V
DD
= 15V
V
OUT
= V
GATE
= 12V
Gate Open
C-Grade, I-Grade
H-Grade
V
FB
= 1.35V, I
SET
Open
V
FB
= 0V, I
SET
Open
V
FB
= 1.35V, R
SET
= 20k
V
DS
= 13.5V, 3A Folded Back, 50W
2
s (Note 6)
V
DS
= 7.5V, 11A Onset of Foldback, 50W
2
s (Note 7)
V = 1.2V
V
SENSE–
= 12V
V
PIN
Rising
l
l
l
l
l
ELECTRICAL CHARACTERISTICS
CONDITIONS
l
l
l
l
l
l
l
l
l
l
l
MIN
2.9
TYP
MAX
15
UNITS
V
mA
V
µA
µA
V/ms
mΩ
mΩ
A
A
A
ms
ms
DC Characteristics
1.6
2.63
1
0.15
4.5
4.5
10
2.0
4.7
30
7
0
4
1.205
10
50
0.55
10
19
2.8
1.235
20
80
0.62
20
20
3.1
0.4
0
1.2
0.1
–80
1.4
1.6
9
1.235
0.21
–100
2
2
10
250
I
OUT
= 300mA
Gate Drive On, V
GATE
= V
OUT
= 12V
Gate Drive Off, V
GATE
= 18V, V
OUT
= 12V
Fast Turn Off, V
GATE
= 18V, V
OUT
= 12V
l
l
l
3
2.85
±300
4
0.6
14.5
16.5
12.4
3.7
6.4
2.73
0
2
0.3
10
10
11.2
2.8
5.6
SOA
Inputs
I
IN
I
SENSE
−
(IN)
V
TH
ΔV
OV(HYST)
ΔV
UV(HYST)
V
UV(RTH)
ΔV
FB(HYST)
R
ISET
Outputs
V
INTVCC
V
OL
I
OH
V
TIMER(H)
V
TIMER(L)
I
TIMER(UP)
I
TIMER(DN)
I
TIMER(RATIO)
A
IMON
BW
IMON
I
OFF(IMON)
I
GATE(UP)
I
GATE(DN)
I
GATE(FST)
MOSFET Safe Operating Area
OV, UV, FB Input Current
SENSE
−
Input Current
OV, UV, FB Threshold Voltage
OV Hysteresis
UV Hysteresis
UV Reset Threshold Voltage
FB Power Good Hysteresis
I
SET
Internal Resistor
INTV
CC
Output Voltage
PG,
FLT
Pin Output Low Voltage
PG ,
FLT
Pin Input Leakage Current
TIMER High Threshold
TIMER Low Threshold
TIMER Pull Up Current
TIMER Pull Down Current
TIMER Current Ratio
I
TIMER(DN)
/I
TIMER(UP)
I
MON
Current Gain
I
MON
Bandwidth
I
MON
Offset Current
Gate Pull-Up Current
Gate Pull-Down Current
Gate Fast Pull-Down Current
±1
±10
1.265
30
110
0.7
30
21
3.3
0.8
±10
1.28
0.3
–120
2.6
2.7
10.5
±9
–29
500
µA
µA
V
mV
mV
V
mV
kΩ
V
UV
Falling
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V
DD
= 5V,15V, I
SINK
= 0mA, –10mA
I
SINK
= 2mA
V = 30V
V
TIMER
Rising
V
TIMER
falling
V
TIMER
= 0V
V
TIMER
= 1.2V
l
l
l
l
l
l
l
l
l
V
µA
V
V
µA
µA
%
µA/A
kHz
µA
µA
µA
mA
0
–18
180
–24
250
140
4233f
For more information
www.linear.com/LTC4233
3
LTC4233
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
DD
= 12V unless otherwise noted.
SYMBOL
t
PHL(GATE)
t
PHL(ILIM)
t
D(ON)
t
D(FAULT)
t
D(CB)
t
D(COOL-DOWN)
PARAMETER
Input High (OV), Input Low (UV) to
GATE Low Propagation Delay
Short Circuit to GATE Low
Turn-On Delay
UV Low to Clear Fault Latch Delay
Circuit Breaker Filter Delay Time
(Internal)
Cool Down Delay (Internal)
V
FB
= 0, Step V
DD
− SENSE
–
to 50mV
l
l
ELECTRICAL CHARACTERISTICS
CONDITIONS
V
GATE
< 17.8V Falling
V
FB
= 0, Step V
DD
− SENSE
−
to 50mV,
V
GATE
< 15V Falling
Step V
UV
to 2V, V
GATE
> 13V
l
l
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MIN
TYP
8
1
MAX
20
5
72
2.7
1200
UNITS
µs
µs
ms
µs
ms
ms
AC Characteristics
24
1.2
600
48
1
2
900
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2:
All currents into pins are positive; all voltages are referenced to
GND unless otherwise specified.
Note 3:
An internal clamp limits the GATE pin to a maximum of 6.5V
above OUT. Driving this pin to voltages beyond the clamp may damage the
device.
Note 4:
This IC includes overtemperature protection that is intended
to protect the device during momentary overload conditions. Junction
temperature will exceed 150°C when overtemperature protection is active.
Continuous operation above the specified maximum operating junction
temperature may impair device reliability.
Note 5:
T
J
is calculated from the ambient temperature, T
A
, and power
dissipation, P
D
, according to the formula:
T
J
= T
A
+ (P
D
• 15°C/W)
Note 6:
SOA tested at room temperature, SOA (i.e. P
2
t) is reduced at
elevated temperatures according to the following formula:
150°C
−
T
J
P t(T
J
)
=
50
W
2
s
•
150°C
−
25°C
2
2
Note 7:
Guaranteed by design and extrapolated from P
2
t limit of 50W
2
s.
4233f
4
For more information
www.linear.com/LTC4233
LTC4233
TYPICAL PERFORMANCE CHARACTERISTICS
I
DD
vs V
DD
2.2
3.5
UV LOW-HIGH THRESHOLD (V)
3.0
2.5
INTV
CC
(V)
25°C
2.0
1.5
1.0
0.5
1.0
0
5
10
15
V
DD
(V)
20
25
30
4233 G01
T
A
= 25°C, V
DD
= 12V unless otherwise noted.
UV Low-High Threshold
vs Temperature
1.240
INTV
CC
Load Regulation
V
DD
= 5V
1.236
125°C
1.8
I
DD
(mA)
V
DD
= 3.3V
1.232
–40°C
1.4
1.228
0
0
–2
–4
–8
I
LOAD
(mA)
–6
–10
–12
–14
1.224
–50 –25
0
4233 G02
25 50 75 100 125 150
TEMPERATURE (°C)
4233 G03
UV Hysteresis vs Temperature
0.10
TIMER PULL-UP CURRENT (µA)
–110
Timer Pull-Up Current
vs Temperature
1000
CURRENT PROPAGATION DELAY (µs)
Current Limit Delay
(t
PHL(ILIM)
vs Overdrive)
UV HYSTERESIS (V)
–105
100
0.08
–100
10
0.06
–95
1
0.04
–50 –25
0
25 50 75 100 125 150
TEMPERATURE (°C)
4233 G04
–90
–50 –25
0
25 50 75 100 125 150
TEMPERATURE (°C)
4233 G05
0.1
0
10
40
20
30
OUTPUT CURRENT (A)
50
60
4233 G06
Current Limit Threshold Foldback
12
10
CURRENT LIMIT VALUE (A)
CURRENT LIMIT VALUE (A)
8
6
4
2
0
12
10
8
6
4
2
0
Current Limit Adjustment
(I
OUT
vs R
SET
)
22
R
ISET
Resistor vs Temperature
I
SET
RESISTOR (k )
21
20
19
>30ms SOA GUARANTEED
0
0.2
0.4
0.6
0.8
FB VOLTAGE (V)
1
1.2
4233 G07
1k
10k
100k
R
SET
( )
1M
10M
4233 G08
18
–50 –25
0
25 50 75 100 125 150
TEMPERATURE (°C)
4233 G09
4233f
For more information
www.linear.com/LTC4233
5