LTC4365
UV, OV and Reverse
Supply Protection Controller
FEATURES
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DESCRIPTION
The LTC
®
4365 protects applications where power supply
input voltages may be too high, too low or even negative.
It does this by controlling the gate voltages of a pair of
external N-channel MOSFETs to ensure that the output
stays within a safe operating range.
The LTC4365 can withstand voltages between –40V and
60V and has an operating range of 2.5V to 34V, while
consuming only 125μA in normal operation.
Two comparator inputs allow configuration of the
overvoltage (OV) and undervoltage (UV) set points using an
external resistive divider. A shutdown pin provides external
control for enabling and disabling the MOSFETs as well
as placing the device in a low current shutdown state. A
fault output provides status of the gate pin pulling low. A
fault is indicated when the part is in shutdown or the input
voltage is outside the UV and OV set points.
L,
LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and
ThinSOT, No R
SENSE
and Hot Swap are trademarks of Linear Technology Corporation. All other
trademarks are the property of their respective owners.
Wide Operating Voltage Range: 2.5V to 34V
Overvoltage Protection to 60V
Reverse Supply Protection to –40V
Blocks 50Hz and 60Hz AC Power
No Input Capacitor or TVS Required for Most
Applications
Adjustable Undervoltage and Overvoltage
Protection Range
Charge Pump Enhances External N-Channel MOSFET
Low Operating Current: 125μA
Low Shutdown Current: 10μA
Fault Status Output
Compact 8-Lead, 3mm × 2mm DFN and
TSOT-23 (ThinSOT™) Packages
APPLICATIONS
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Portable Instrumentation
Industrial Automation
Laptops
Automotive
TYPICAL APPLICATION
12V Automotive Application
V
IN
12V
Si4946
V
OUT
3A
30V
VALID
WINDOW
GND
V
OUT
UV = 3.5V
OV = 18V
V
IN
Load Protected from Reverse and Overvoltage at V
IN
V
IN
510k
1820k
UV
243k
OV
59k
GATE
LTC4365
V
OUT
V
OUT
SHDN
10V/DIV
FAULT
–30V
V
IN
1s/DIV
GND
4365 TA01a
4365 TA01b
OV = 18V
UV = 3.5V
4365f
1
LTC4365
ABSOLUTE MAXIMUM RATINGS
Supply Voltage (Note 1)
V
IN
.......................................................... –40V to 60V
Input Voltages (Note 3)
UV,
SHDN
.............................................. –0.3V to 60V
OV ............................................................ –0.3V to 6V
V
OUT
....................................................... –0.3V to 40V
Output Voltages (Note 4)
FAULT
..................................................... –0.3V to 60V
GATE ....................................................... –40V to 45V
Operating Ambient Temperature Range
LTC4365C ................................................ 0°C to 70°C
LTC4365I .............................................–40°C to 85°C
LTC4365H .......................................... –40°C to 125°C
Storage Temperature Range .................. –65°C to 150°C
Lead Temperature (Soldering, 10 sec)
for TSOT Only ................................................... 300°C
PIN CONFIGURATION
TOP VIEW
GND 1
OV 2
UV 3
V
IN
4
9
GND
8
7
6
5
SHDN
FAULT
V
OUT
GATE
TOP VIEW
V
IN
UV
OV
GND
1
2
3
4
8
7
6
5
GATE
V
OUT
FAULT
SHDN
DDB PACKAGE
8-LEAD (3mm
×
2mm) PLASTIC DFN
T
JMAX
= 150°C,
θ
JA
= 76°C/W
EXPOSED PAD (PIN 9) PCB GROUND CONNECTION OPTIONAL
TS8 PACKAGE
8-LEAD PLASTIC TSOT-23
T
JMAX
= 150°C,
θ
JA
= 195°C/W
ORDER INFORMATION
Lead Free Finish
TAPE AND REEL (MINI)
LTC4365CDDB#TRMPBF
LTC4365IDDB#TRMPBF
LTC4365HDDB#TRMPBF
LTC4365CTS8#TRMPBF
LTC4365ITS8#TRMPBF
LTC4365HTS8#TRMPBF
TAPE AND REEL
LTC4365CDDB#TRPBF
LTC4365IDDB#TRPBF
LTC4365HDDB#TRPBF
LTC4365CTS8#TRPBF
LTC4365ITS8#TRPBF
LTC4365HTS8#TRPBF
PART MARKING*
LFKS
LFKS
LFKS
LTFKT
LTFKT
LTFKT
PACKAGE DESCRIPTION
8-Lead (3mm × 2mm) Plastic DFN
8-Lead (3mm × 2mm) Plastic DFN
8-Lead (3mm × 2mm) Plastic DFN
8-Lead Plastic TSOT-23
8-Lead Plastic TSOT-23
8-Lead Plastic TSOT-23
TEMPERATURE RANGE
0°C to 70°C
–40°C to 85°C
–40°C to 125°C
0°C to 70°C
–40°C to 85°C
–40°C to 125°C
TRM = 500 pieces. *Temperature grades are identified by a label on the shipping container.
Consult LTC Marketing for parts specified with wider operating temperature ranges.
Consult LTC Marketing for information on 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/
4365f
2
LTC4365
ELECTRICAL CHARACTERISTICS
SYMBOL
V
IN
, V
OUT
V
IN
I
VIN
Input Voltage Range
Input Supply Current
Operating Range
Protection Range
SHDN
= 0V, V
IN
= V
OUT
, –40°C to 85°C
SHDN
= 0V, V
IN
= V
OUT
, –40°C to 125°C
SHDN
= 2.5V
V
IN
= –40V, V
OUT
= 0V
V
IN
Rising
SHDN
= 0V, V
IN
= V
OUT
SHDN
= 2.5V, V
IN
= V
OUT
V
IN
= –40V, V
OUT
= 0V
V
IN
= V
OUT
= 5.0V, I
GATE
= –1μA
V
IN
= V
OUT
= 12V to 34V, I
GATE
= –1μA
GATE = V
IN
= V
OUT
= 12V
Fast Shutdown, GATE = 20V, V
IN
= V
OUT
= 12V
Gentle Shutdown, GATE = 20V, V
IN
= V
OUT
= 12V
C
GATE
= 2.2nF, UV or OV Fault
C
GATE
= 2.2nF,
SHDN
Falling, V
IN
= V
OUT
= 12V
V
IN
= 12V, Power Good to
∆V
GATE
> 0V
UV Falling
→
ΔV
GATE
= 0V
OV Rising
→
ΔV
GATE
= 0V
l
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l
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l
l
l
l
l
l
l
l
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
IN
= 2.5V to 34V, unless otherwise noted. (Note 2)
PARAMETER
CONDITIONS
MIN
2.5
–40
10
10
25
–1.2
1.8
2.2
6
100
20
3
7.4
–12
31
50
150
26
492.5
492.5
20
20
3.6
8.4
–20
50
90
2
250
36
500
500
25
25
1
TYP
MAX
34
60
50
100
150
–1.8
2.4
30
250
50
4.2
9.8
–30
72
150
4
350
49
507.5
507.5
32
32
±10
2
UNITS
V
V
μA
μA
μA
mA
V
μA
μA
μA
V
V
μA
mA
μA
μs
μs
ms
mV
mV
mV
mV
nA
μs
I
VIN(R)
V
IN(UVLO)
I
VOUT
Reverse Input Supply Current
Input Supply Undervoltage Lockout
V
OUT
Input Current
GATE
ΔV
GATE
I
GATE(UP)
N-Channel Gate Drive
(GATE-V
OUT
)
N-Channel Gate Pull Up Current
I
GATE(FAST)
N-Channel Gate Fast Pull Down Current
I
GATE(SLOW)
N-Channel Gate Gentle Pull Down Current
t
GATE(FAST)
N-Channel Gate Fast Turn Off Delay
t
GATE(SLOW)
N-Channel Gentle Turn Off Delay
t
RECOVERY
UV, OV
V
UV
V
OV
V
UVHYST
V
OVHYST
I
LEAK
t
FAULT
SHDN
V
SHDN
I
SHDN
t
START
t
SHDN(F)
t
LOWPWR
FAULT
V
OL
I
FAULT
FAULT
Output Voltage Low
FAULT
Leakage Current
SHDN
Input Threshold
SHDN
Input Current
Delay Coming Out of Shutdown Mode
SHDN
to
FAULT
Asserted
Delay from Turn Off to Low Power Operation
UV Input Threshold Voltage
OV Input Threshold Voltage
UV Input Hysteresis
OV Input Hysteresis
UV, OV Leakage Current
UV, OV Fault Propagation Delay
GATE Recovery Delay Time
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l
l
l
l
l
V = 0.5V, V
IN
= 34V
Overdrive = 50mV
V
IN
= V
OUT
= 12V
SHDN
Falling to ΔV
GATE
= 0V
SHDN
= 0.75V, V
IN
= 34V
SHDN
Rising to ΔV
GATE
> 0V, V
IN
= V
OUT
= 12V
V
IN
= V
OUT
= 12V
V
IN
= V
OUT
= 12V
I
FAULT
= 500μA
FAULT
= 5V, V
IN
= 34V
l
l
l
l
l
0.4
400
26
0.75
800
1.5
36
0.15
±20
1.2
±10
1200
3
55
0.4
V
nA
μs
μs
ms
V
nA
l
l
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 noted.
Note 3.
These pins can be tied to voltages below –0.3V through a resistor
that limits the current below 1mA.
Note 4.
The GATE pin is referenced to V
OUT
and does not exceed 44V for
the entire operating range.
4365f
3
LTC4365
TYPICAL PERFORMANCE CHARACTERISTICS
V
IN
Operating Current vs
Temperature
100
SHDN
= 2.5V
V
OUT
= V
IN
80
V
IN
= 34V
20
I
VIN
(μA)
I
VIN
(μA)
70°C
15
25°C
10
20
V
IN
= 2.5V
0
–50
–25
75
25
0
50
TEMPERATURE (°C)
100
125
–45°C
5
0
0
5
10
20
15
V
IN
(V)
–1200
25°C
I
VIN
(μA)
60
V
IN
= 12V
–400
–45°C
30
V
IN
= V
OUT
SHDN
= 0V
25
125°C
0
V
IN
Shutdown Current vs V
IN
400
V
IN
Current vs V
IN
(–40 to 60V)
SHDN
= UV = 0V
25°C
40
–800
125°C
25
30
35
–1600
–50
–25
0
V
IN
(V)
25
50
75
4365 G03
4365 G01
4365 G02
V
OUT
Operating Current vs
Temperature
200
SHDN
= 2.5V
V
IN
= V
OUT
160
V
OUT
= 34V
I
VOUT
(μA)
I
VOUT
(μA)
120
V
OUT
= 12V
80
15
20
V
OUT
Shutdown Current vs
Temperature
25
SHDN
= 0V
V
IN
= V
OUT
20
V
OUT
Current vs Reverse V
IN
V
OUT
= 0V
–45°C
I
VOUT
(μA)
V
OUT
= 34V
15
25°C
10
125°C
5
V
OUT
= 2.5V
10
V
OUT
= 12V
5
40
V
OUT
= 2.5V
0
–50
0
–50
–25
0
75
25
50
TEMPERATURE (C°)
100
125
–25
0
25
50
75
TEMPERATURE (C°)
100
125
0
0
–10
–30
–20
V
IN
(V)
–40
–50
4365 G06
4365 G04
4365 G05
12
10
8
ΔV
GATE
(V)
6
4
2
0
GATE Drive vs V
IN
10
V
OUT
= 0V
8
V
OUT
= V
IN
ΔV
GATE
(V)
6
GATE Drive vs Temperature
25
V
IN
= V
OUT
= 34V
I
GATE
= –1μA
V
IN
= V
OUT
= 12V
I
GATE(UP)
(μA)
20
GATE Current vs GATE Drive
V
IN
= V
OUT
= 12V
125°C
15
25°C
4
10
–45°C
5
2
T = 25°C
I
GATE
= –1μA
0
5
10
15
20
V
IN
(V)
25
30
35
V
IN
= V
OUT
= 2.5V
0
–50
–25
75
25
0
50
TEMPERATURE (°C)
100
0
125
0
2
4
6
ΔV
GATE
(V)
8
10
4365 G09
4365 G07
4365 G08
4365f
4
LTC4365
TYPICAL PERFORMANCE CHARACTERISTICS
UV Threshold vs Temperature
507.5
V
IN
= V
OUT
= 12V
505.0
502.5
V
UV
(mV)
500.0
497.5
495.0
492.5
–50
V
OV
(mV)
505.0
0.75
502.5
500.0
497.5
0.25
495.0
492.5
–50
0
–75
UV
OV
–25
75
0
50
25
TEMPERATURE (°C)
100
125
–25
75
0
50
25
TEMPERATURE (°C)
100
125
–25
75
25
125
TEMPERATURE (°C)
175
4365 G12
OV Threshold vs Temperature
507.5
V
IN
= V
OUT
= 12V
1.00
UV/OV Leakage vs Temperature
V
UV/OV
= 0.5V
V
IN
= 12V
I
LEAK
(nA)
4365 G11
0.50
4365 G10
UV/OV Propagation Delay vs
Overdrive
20
V
IN
= V
OUT
= 12V
T = 25°C
50
Recovery Delay Time vs
Temperature
50
Recovery Delay Time vs V
IN
–45°C
125°C
25°C
30
16
t
RECOVERY
(ms)
40
V
IN
= 34V
t
RECOVERY
(ms)
100
125
V
IN
= 12V
40
t
FAULT
(μs)
12
30
8
20
V
IN
= 2.5V
20
4
10
10
0
1
10
100
OVERDRIVE (mV)
1000
4365 G13
0
–50
–25
75
25
0
50
TEMPERATURE (°C)
0
0
5
10
20
15
V
IN
(V)
25
30
35
4365 G15
4365 G14
AC Blocking
1V/DIV
V
OUT
GND
5V/DIV
Turn-On Timing
100μF 12Ω LOAD ON V
OUT
,
60V SI9945 DUAL NCH MOSFET
V
IN
= 12V
V
OUT
GND
10μF 1k LOAD ON V
OUT
,
60V DUAL NCH MOSFET
2.5ms/DIV
4365 G16
Turn-Off Timing
GATE
5V/DIV
V
OUT
GND
3V/DIV
SHDN
250μs/DIV
4365 G18
GATE
100μF 12Ω LOAD ON V
OUT
,
60V SI9945 DUAL NCH MOSFET
V
IN
20V/DIV
GND
GATE
3V/DIV
SHDN
4365 G17
GND
250μs/DIV
GND
4365f
5