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 resistor
in a single package for small form factor applications. A
dedicated 12V version (LTC4217-12) contains preset 12V
specific thresholds, while the standard LTC4217 allows
adjustable thresholds.
The LTC4217 provides separate inrush current control
and a 5% accurate 2A current limit with foldback cur-
rent limiting. The current limit threshold can be adjusted
dynamically using an external 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.
L,
LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. Hot Swap is a trademark of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
Small Footprint
33mΩ MOSFET with R
SENSE
Wide Operating Voltage Range: 2.9V to 26.5V
Adjustable, 5% 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% Accurate Undervoltage and Overvoltage
Protection
Available in 20-Lead TSSOP and 16-Lead
5mm
×
3mm DFN Packages
APPLICATIONS
n
n
n
RAID Systems
Server I/O Cards
Industrial
TYPICAL APPLICATION
12V, 1.5A Card Resident Application
12V
AUTO
RETRY
V
DD
UV
LTC4217DHC-12
FLT
TIMER
INTV
CC
0.1μF
GND
PG
I
SET
I
MON
20k
4217 TA01a
Power-Up Waveforms
+
V
OUT
12V
330μF 1.5A
OUT
12V
10k
V
IN
10V/DIV
I
IN
0.1A/DIV
V
OUT
10V/DIV
P
G
10V/DIV
4217 TA01b
ADC
25ms/DIV
4217fc
1
LTC4217
ABSOLUTE MAXIMUM RATINGS
(Notes 1, 2)
Supply Voltage (V
DD
) ................................. –0.3V to 28V
Input Voltages
FB, OV, UV .............................................. –0.3V to 12V
TIMER................................................... –0.3V to 3.5V
SENSE .............................V
DD
– 10V or – 0.3V to V
DD
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 Temperature Range
LTC4217C ................................................ 0°C to 70°C
LTC4217I.............................................. –40°C to 85°C
Junction Temperature (Notes 4, 5)........................ 125°C
Storage Temperature Range................... –65°C to 150°C
Lead Temperature (Soldering, 10 sec)
FE Package Only ............................................... 300°C
PIN CONFIGURATION
LTC4217
LTC4217-12
LTC4217
TOP VIEW
TOP VIEW
V
DD
UV
OV
TIMER
INTV
CC
GND
OUT
OUT
1
2
3
4
5
6
7
8
17
SENSE
16 V
DD
15 I
SET
14 I
MON
13 FB
12
FLT
11 PG
10 GATE
9
OUT
SENSE
V
DD
UV
OV
TIMER
INTV
CC
GND
OUT
OUT
1
2
3
4
5
6
7
8
9
21
SENSE
20 SENSE
19 V
DD
18 I
SET
17 I
MON
16 FB
15 FLT
14 PG
13 GATE
12 OUT
11 SENSE
SENSE 10
DHC PACKAGE
16-LEAD (5mm 3mm) PLASTIC DFN
T
JMAX
= 125°C,
θ
JA
= 43°C/W
EXPOSED PAD (PIN 17) IS SENSE,
θ
JA
= 43°C/W SOLDERED, OTHERWISE
θ
JA
= 140°C/W
FE PACKAGE
20-LEAD PLASTIC TSSOP
T
JMAX
= 125°C,
θ
JA
= 38°C/W
EXPOSED PAD (PIN 21) IS SENSE,
θ
JA
= 38°C/W SOLDERED, OTHERWISE
θ
JA
= 130°C/W
4217fc
2
LTC4217
ORDER INFORMATION
LEAD FREE FINISH
LTC4217CDHC-12#PBF
LTC4217IDHC-12#PBF
LTC4217CDHC#PBF
LTC4217IDHC#PBF
LTC4217CFE#PBF
LTC4217IFE#PBF
LEAD BASED FINISH
LTC4217CDHC-12
LTC4217IDHC-12
LTC4217CDHC
LTC4217IDHC
LTC4217CFE
LTC4217IFE
TAPE AND REEL
PART MARKING*
PACKAGE DESCRIPTION
16-Lead (5mm
×
3mm) Plastic DFN
16-Lead (5mm
×
3mm) Plastic DFN
16-Lead (5mm
×
3mm) Plastic DFN
16-Lead (5mm
×
3mm) Plastic DFN
20-Lead Plastic TSSOP
20-Lead Plastic TSSOP
PACKAGE DESCRIPTION
16-Lead (5mm
×
3mm) Plastic DFN
16-Lead (5mm
×
3mm) Plastic DFN
16-Lead (5mm
×
3mm) Plastic DFN
16-Lead (5mm
×
3mm) Plastic DFN
20-Lead Plastic TSSOP
20-Lead Plastic TSSOP
TEMPERATURE RANGE
0°C to 70°C
–40°C to 85°C
0°C to 70°C
–40°C to 85°C
0°C to 70°C
–40°C to 85°C
TEMPERATURE RANGE
0°C to 70°C
–40°C to 85°C
0°C to 70°C
–40°C to 85°C
0°C to 70°C
–40°C to 85°C
LTC4217CDHC-12#TRPBF 421712
LTC4217IDHC-12#TRPBF 421712
LTC4217CDHC#TRPBF
LTC4217IDHC#TRPBF
LTC4217CFE#TRPBF
LTC4217IFE#TRPBF
TAPE AND REEL
LTC4217CDHC-12#TR
LTC4217IDHC-12#TR
LTC4217CDHC#TR
LTC4217IDHC#TR
LTC4217CFE#TR
LTC4217IFE#TR
4217
4217
LTC4217FE
LTC4217FE
PART MARKING*
421712
421712
4217
4217
LTC4217FE
LTC4217FE
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
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/
ELECTRICAL CHARACTERISTICS
SYMBOL
V
DD
I
DD
V
DD(UVL)
V
DD(UVTH)
ΔV
DD(UVHYST)
V
DD(OVTH)
ΔV
DD(OVHYST)
V
OUT(PGTH)
ΔV
OUT(PGHYST)
I
OUT
PARAMETER
Input Supply Range
Input Supply Current
Input Supply Undervoltage Lockout
Input Supply Undervoltage Threshold
Input Supply Undervoltage Hysteresis
Input Supply Overvoltage Threshold
Input Supply Overvoltage Hysteresis
Output Power Good Threshold
Output Power Good Hysteresis
OUT Pin Leakage Current
DC Characteristics
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.
CONDITIONS
l
MIN
2.9
TYP
MAX
26.5
UNITS
V
mA
V
V
mV
V
mV
V
mV
μA
μA
μA
V/ms
mΩ
A
A
A
A
MOSFET On, No Load
V
DD
Rising
LTC4217-12, V
DD
Rising
LTC4217-12
LTC4217-12, V
DD
Rising
LTC4217-12
LTC4217-12, V
OUT
Rising
LTC4217-12
V
OUT
= V
GATE
= 0V, V
DD
= 26.5V
V
OUT
= V
GATE
= 12V, LTC4217
V
OUT
= V
GATE
= 12V, LTC4217-12
Note 6
V
FB
= 1.23V
V
FB
= 1.23V
V
FB
= 0V
V
FB
= 1.23V, R
SET
= 20kΩ
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
1.6
2.65
9.6
520
14.7
183
10.2
127
1
50
0.15
15
1.9
1.85
0.35
0.85
2.73
9.88
640
15.05
244
10.5
170
0
2
70
0.3
33
2
2
0.5
1
3
2.85
10.2
760
15.4
305
10.8
213
±150
4
90
0.55
50
2.1
2.15
0.7
1.17
ΔV
GATE
/Δt
R
ON
I
LIM(TH)
GATE Pin Turn-On Ramp Rate
MOSFET + Sense Resistor On Resistance
Current Limit Threshold
4217fc
3
LTC4217
ELECTRICAL CHARACTERISTICS
SYMBOL
Inputs
I
IN
R
IN
V
TH
ΔV
OV(HYST)
ΔV
UV(HYST)
V
UV(RTH)
ΔV
FB(HYST)
R
ISET
Outputs
V
OL
I
OH
V
TIMER(H)
V
TIMER(L)
I
TIMER(UP)
I
TIMER(DN)
I
TIMER(RATIO)
A
IMON
I
OFF(IMON)
I
GATE(UP)
I
GATE(DN)
I
GATE(FST)
t
PHL(GATE)
t
PHL(ILIM)
t
D(ON)
t
D(CB)
t
D(AUTO-RETRY)
PG,
FLT
Pin Output Low Voltage
PG,
FLT
Pin Input Leakage Current
TIMER Pin High Threshold
TIMER Pin Low Threshold
TIMER Pin Pull-Up Current
TIMER Pin Pull-Down Current
TIMER Pin Current Ratio I
TIMER(DN)
/I
TIMER(UP)
I
MON
Pin Current Gain
I
MON
Pin Offset Current
Gate Pull-Up Current
Gate Pull-Down Current
Gate Fast Pull-Down Current
Input High (OV), Input Low (UV) to Gate Low
Propagation Delay
Short-Circuit to Gate Low
Turn-On Delay
Circuit Breaker Filter Delay Time (Internal)
Auto-Retry Turn-On Delay (Internal)
I
OUT
= 2A
I
OUT
= 132mA
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
V
GATE
< 16.5V Falling
V
FB
= 0, Step I
SENSE
to 1.2A,
V
GATE
< 16.5V Falling
Step V
UV
to 2V, V
GATE
> 13V
V
FB
= 0V, Step I
SENSE
to 1.2A
l
l
l
l
l
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.
PARAMETER
OV, UV, FB Pin Input Current
OV, UV, FB Pin Input Resistance
OV, UV, FB Pin Threshold Voltage
OV Pin Hysteresis
UV Pin Hysteresis
UV Pin Reset Threshold Voltage
FB Pin Power Good Hysteresis
I
SET
Pin Output Resistor
I
OUT
= 2mA
V
OUT
= 30V
V
TIMER
Rising
V
TIMER
Falling
V
TIMER
= 0V
V
TIMER
= 1.2V
V
UV
Falling
CONDITIONS
V
IN
= 1.2V, LTC4217
LTC4217-12
V
IN
Rising
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
MIN
TYP
0
MAX
±1
23
1.26
30
110
0.7
30
20.5
0.8
±10
1.28
0.3
–120
2.6
2.7
52.5
±7.5
–29
340
UNITS
μA
kΩ
V
mV
mV
V
mV
kΩ
V
μA
V
V
μA
μA
%
μA/A
μA
μA
μA
mA
13
1.21
10
50
0.55
10
19.5
18
1.235
20
80
0.62
20
20
0.4
0
1.2
0.1
–80
1.4
1.6
47.5
–19
190
1.235
0.21
–100
2
2
50
0
–24
250
140
8
1
AC Characteristics
10
5
150
2.7
150
μs
μs
ms
ms
ms
50
1.5
50
100
2
100
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 125°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:
LTC4217DHC, LTC4217DHC-12: T
J
= T
A
+ (P
D
• 43°C/W)
LTC4217FE: T
J
= T
A
+ (P
D
• 38°C/W)
Note 6:
For the DHC package, switch on-resistance is guaranteed by
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