ler that drives an external N-channel MOSFET to replace
a Schottky diode. It controls the forward-voltage drop
across the MOSFET to ensure smooth current delivery
without oscillation even at light loads. If a power source
fails or is shorted, a fast turn-off minimizes reverse cur-
rent transients. A shutdown mode is available to reduce
the quiescent current to 9μA for load switch and 14µA for
ideal diode applications.
When used in high current diode applications, the LTC4359
reduces power consumption, heat dissipation, voltage loss
and PC board area. With its wide operating voltage range,
the ability to withstand reverse input voltage, and high
temperature rating, the LTC4359 satisfies the demanding
requirements of both automotive and telecom applications.
The LTC4359 also easily ORs power sources in systems
with redundant supplies.
All registered trademarks and trademarks are the property of their respective owners.
Reduces Power Dissipation by Replacing a Power
Schottky Diode
Wide Operating Voltage Range: 4V to 80V
Reverse Input Protection to – 40V
Low 9µA Shutdown Current
Low 150μA Operating Current
Smooth Switchover without Oscillation
Controls Single or Back-to-Back N-Channel MOSFETs
Available in 6-Pin (2mm
×
3mm) DFN, 8-Lead MSOP
and 8-Lead SO Packages
APPLICATIONS
n
n
n
n
n
n
Automotive Battery Protection
Redundant Power Supplies
Supply Holdup
Telecom Infrastructure
Computer Systems/Servers
Solar Systems
TYPICAL APPLICATION
12V, 20A Automotive Reverse-Battery Protection
V
IN
12V
BSC028N06NS
SMAT70A
70V
SMAJ24A
24V
IN
SHDN
SOURCE
LTC4359
V
SS
4359 TA01
Power Dissipation vs Load Current
10
V
OUT
TO LOAD
POWER DISSIPATION (W)
8
SCHOTTKY DIODE (SBG2040CT)
GATE
OUT
47nF
6
POWER
SAVED
4
1k
2
MOSFET (BSC028N06NS)
0
0
5
10
CURRENT (A)
15
20
4359 TA01a
Document Feedback
For more information
www.analog.com
1
Rev D
LTC4359
ABSOLUTE MAXIMUM RATINGS
(Notes 1, 2)
IN, SOURCE,
SHDN
................................... –40V to 100V
OUT (Note 3) ................................................–2V to 100V
IN – OUT ..................................................–100V to 100V
IN – SOURCE .................................................–1V to 80V
GATE – SOURCE (Note 4) .........................–0.3V to +10V
Operating Ambient Temperature Range
LTC4359C ................................................ 0°C to 70°C
LTC4359I ............................................. −40°C to 85°C
LTC4359H .......................................... −40°C to 125°C
Storage Temperature Range .................. −65°C to 150°C
Lead Temperature (Soldering, 10 sec)
MS, SO Packages ............................................. 300°C
PIN CONFIGURATION
TOP VIEW
OUT 1
GATE 2
SOURCE 3
7
6 V
SS
5
SHDN
4 IN
GATE
SOURCE
NC
IN
1
2
3
4
TOP VIEW
8
7
6
5
OUT
NC
V
SS
SHDN
GATE 1
SOURCE 2
NC 3
IN 4
TOP VIEW
8
7
6
5
OUT
NC
V
SS
SHDN
DCB PACKAGE
6-LEAD (2mm
×
3mm) PLASTIC DFN
T
JMAX
= 150°C,
θ
JA
= 64°C/W
EXPOSED PAD (PIN 7) PCB V
SS
CONNECTION OPTIONAL
MS8 PACKAGE
8-LEAD PLASTIC MSOP
T
JMAX
= 150°C,
θ
JA
= 163°C/W
S8 PACKAGE
8-LEAD PLASTIC SO
T
JMAX
= 150°C,
θ
JA
= 130°C/W
ORDER INFORMATION
TAPE AND REEL (MINI)
LTC4359CDCB#TRMPBF
LTC4359IDCB#TRMPBF
LTC4359HDCB#TRMPBF
TUBE
LTC4359CMS8#PBF
LTC4359IMS8#PBF
LTC4359HMS8#PBF
LTC4359CS8#PBF
LTC4359IS8#PBF
TAPE AND REEL
LTC4359CDCB#TRPBF
LTC4359IDCB#TRPBF
LTC4359HDCB#TRPBF
TAPE AND REEL
LTC4359CMS8#TRPBF
LTC4359IMS8#TRPBF
LTC4359HMS8#TRPBF
LTC4359CS8#TRPBF
LTC4359IS8#TRPBF
http://www.linear.com/product/LTC4359#orderinfo
PART MARKING*
LFKF
LFKF
LFKF
PART MARKING*
LTFKD
LTFKD
LTFKD
4359
4359
PACKAGE DESCRIPTION
6-Lead (2mm
×
3mm) Plastic DFN
6-Lead (2mm
×
3mm) Plastic DFN
6-Lead (2mm
×
3mm) Plastic DFN
PACKAGE DESCRIPTION
8-Lead Plastic MSOP
8-Lead Plastic MSOP
8-Lead Plastic MSOP
8-Lead Plastic SO
8-Lead Plastic SO
TEMPERATURE RANGE
0°C to 70°C
–40°C to 85°C
–40°C to 125°C
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
LTC4359HS8#PBF
LTC4359HS8#TRPBF
4359
8-Lead Plastic SO
–40°C to 125°C
Consult ADI 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/.
Some packages are available in 500 unit reels through
designated sales channels with #TRMPBF suffix.
2
Rev D
For more information
www.analog.com
LTC4359
ELECTRICAL CHARACTERISTICS
SYMBOL
V
IN
I
IN
PARAMETER
Operating Supply Range
IN Current
IN = 12V
IN = OUT = 12V,
SHDN
= 0V
IN = OUT = 24V,
SHDN
= 0V
IN = −40V
IN = 12V, In Regulation
IN = 12V, ∆V
SD
= −1V
IN = OUT = 12V,
SHDN
= 0V
IN = OUT = 24V,
SHDN
= 0V
OUT = 12V, IN =
SHDN
= 0V
IN = 12V, ∆V
SD
= −1V
IN = SOURCE = 12V,
SHDN
= 0V
SOURCE = –40V
IN = 4V, I
GATE
= 0, −1µA
IN = 8V to 80V; I
GATE
= 0, –1µA
GATE = IN, ∆V
SD
= 0.1V
Fault Condition, ∆V
GATE
= 5V, ∆V
SD
= −1V
Shutdown Mode, ∆V
GATE
= 5V, ∆V
SD
= 0.7V
∆V
SD
= 0.1V to −1V, ∆V
GATE
< 2V,
C
GATE
= 0pF
IN = 12V, SOURCE = OUT = 0V,
SHDN
= 0V to 2V
∆V
GATE
> 4.5V, C
GATE
= 0pF
IN = 4V to 80V
IN = 4V to 80V
SHDN
= 0.5V, LTC4359I, LTC4359C
SHDN
= 0.5V, LTC4359H
SHDN
= −40V
Maximum Allowable Leakage, V
IN
= 4V
GATE = 0V, I
GATE(DOWN)
= 1mA
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, IN = 12V, SOURCE = IN, unless otherwise noted.
CONDITIONS
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
MIN
4
TYP
150
9
15
–15
5
120
0.8
0.8
6
150
4
–0.8
5.5
12
30
–10
130
0.3
200
MAX
80
200
20
30
–40
7.5
220
3
3
12
200
15
–1.5
15
15
45
–14
180
0.5
UNITS
V
µA
µA
µA
µA
µA
µA
µA
µA
µA
µA
µA
mA
V
V
mV
µA
mA
mA
µs
µs
0
3
I
OUT
OUT Current
I
SOURCE
∆V
GATE
∆V
SD
I
GATE(UP)
SOURCE Current
1
–0.4
4.5
10
20
–6
70
0.6
Gate Drive (GATE–SOURCE)
Source-Drain Regulation Voltage (IN –OUT) ∆V
GATE
= 2.5V
Gate Pull-Up Current
I
GATE(DOWN)
Gate Pull-Down Current
t
OFF
t
ON
V
SHDN(TH)
V
SHDN(FLT)
I
SHDN
Gate Turn-Off Delay Time
Gate Turn-On Delay Time
SHDN
Pin Input Threshold
SHDN
Pin Float Voltage
SHDN
Pin Current
0.6
0.6
–1
–0.5
–0.4
–0.9
1.2
1.75
–3
–3
–0.8
100
–1.8
2
2.5
–5
–5
–1.5
–2.7
V
V
µA
µA
mA
nA
V
V
SOURCE(TH)
Reverse SOURCE Threshold for GATE Off
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
V
SS
unless otherwise specified.
Note 3.
An internal clamp limits the OUT pin to a minimum of 100V above
V
SS
. Driving this pin with more current than 1mA may damage the device.
Note 4.
An internal clamp limits the GATE pin to a minimum of 10V above
IN or 100V above V
SS
. Driving this pin to voltages beyond the clamp may
damage the device.
For more information
www.analog.com
3
Rev D
LTC4359
TYPICAL PERFORMANCE CHARACTERISTICS
IN Current in Regulation
200
50
IN Current in Shutdown
IN = SOURCE = OUT
SHDN
= 0V
10
SOURCE Current in Shutdown
IN = SOURCE = OUT
SHDN
= 0V
150
40
I
SOURCE
(µA)
T
A
= 125°C
T
A
= 85°C
T
A
= 25°C
T
A
= –40°C
0
20
40
V
IN
(V)
60
80
4359 G02
8
I
IN
(µA)
100
I
IN
(µA)
30
6
20
4
T
A
= 125°C
T
A
= 85°C
T
A
= 25°C
T
A
= –40°C
0
20
40
V
SOURCE
(V)
60
80
4359 G03
50
10
2
0
0
20
40
V
IN
(V)
60
80
4359 G01
0
0
OUT Current
vs Forward Voltage Drop
160
V
IN
= 48V
V
IN
= 12V
V
IN
= 4V
200
SOURCE Current
vs Forward Voltage Drop
IN = SOURCE
–2
Total Negative Current
vs Negative Input Voltage
IN = SOURCE=
SHDN
I
IN
+ I
SOURCE
+ I
SHDN
(mA)
1
4359 G05
120
I
SOURCE
(µA)
I
OUT
(µA)
150
V
SOURCE
> 12V
100
–1.5
80
–1
50
V
SOURCE
= 4V
0
40
–0.5
0
–1
–0.5
0
∆V
SD
(V)
0.5
1
4359 G04
–50
–1
–0.5
0
∆V
SD
(V)
0.5
0
0
–10
–20
VOLTAGE (V)
–30
–40
4359 G06
Gate Current
vs Forward Voltage Drop
–20
–10
0
∆V
GATE
(V)
I
GATE
(µA)
10
20
30
40
–50
0
V
IN
= V
SOURCE
= 12V
V
GATE
= V
IN
+2.5V
15
Gate Drive vs Gate Current
IN = SOURCE
V
IN
> 12V
V
IN
= 8V
t
OFF
(ns)
600
800
Gate Turn-Off Time
vs GATE Capacitance
V
IN
= 12V
∆V
SD
= 0.1V –1V
10
400
5
V
IN
= 4V
200
0
50
∆V
SD
(mV)
100
150
4359 G07
0
–5
I
GATE
(µA)
–10
–15
4359 G08
0
0
2
6
4
C
GATE
(nF)
8
10
4359 G09
4
Rev D
For more information
www.analog.com
LTC4359
TYPICAL PERFORMANCE CHARACTERISTICS
Gate Turn-Off Time
vs Initial Overdrive
200
V
IN
= 12V
∆V
SD
= V
INITIAL
–1V
1500
Gate Turn-Off Time
vs Final Overdrive
V
IN
= 12V
∆V
SD
= 45mV
10
V
FINAL
8
CURRENT (A)
1000
Load Current
vs Forward Voltage Drop
FDMS86101
FDB3632
6
150
t
PD
(ns)
t
PD
(ns)
100
500
50
4
FDS3732
2
0
0
0.25
0.5
V
INITIAL
(V)
0.75
1
4359 G10
0
0
–0.25
–0.5
V
FINAL
(V)
–0.75
–1
4359 G11
0
0
25
50
∆V
SD
(mV)
75
100
4359 G12
PIN FUNCTIONS
Exposed Pad (DCB Package Only):
Exposed pad may be
left open or connected to V
SS
.
GATE:
Gate Drive Output. The GATE pin pulls high, enhanc-
ing the N-channel MOSFET when the load current creates
more than 30mV of voltage drop across the MOSFET.
When the load current is small, the gate is actively driven
to maintain 30mV across the MOSFET. If reverse current
flows, a fast pull-down circuit connects the GATE to the
SOURCE pin within 0.3μs, turning off the MOSFET.
IN:
Voltage Sense and Supply Voltage. IN is the anode of
the ideal diode. The voltage sensed at this pin is used to
control the MOSFET gate.
NC (MS8 and S8 Packages):
No Connection. Not internally
connected.
OUT:
Drain Voltage Sense. OUT is the cathode of the ideal
diode and the common output when multiple LTC4359s
are configured as an ideal diode-OR. It connects either di-
rectly or through a 2k resistor to the drain of the N-channel
MOSFET. The voltage sensed at this pin is used to control
the MOSFET gate.
SHDN:
Shutdown Control Input. The LTC4359 can be
shut down to a low current mode by pulling the
SHDN
pin below 0.6V. Pulling this pin above 2V or disconnect-
ing it allows an internal 2.6μA current source to turn the
part on. Maintain board leakage to less than 100nA for
proper operation. The
SHDN
pin can be pulled up to 100V
or down to – 40V with respect to V
SS
without damage. If
the shutdown feature is not used, connect
SHDN
to IN.
SOURCE:
Source Connection. SOURCE is the return path
of the gate fast pull-down. Connect this pin as close as
possible to the source of the external N-channel MOSFET.
