LTC4360CSC8-1TRMPBF LINER [Linear Technology], LTC4360CSC8-1TRMPBF Datasheet - Page 9

• Manufacturer Part Number: LTC4360CSC8-1TRMPBF
• Description: Overvoltage Protection Controller
• Manufacturer: LINER [Linear Technology]

APPLICATIONS INFORMATION
As the IN pin can withstand up to 80V, a high voltage N-
channel MOSFET can be used to protect the system against
rugged abuse from high transient or DC voltages up to the
BV
into the LTC4360 controlling a 60V rated MOSFET.
Input transients also occur when the current through the
cable inductance changes abruptly. This can happen when
the LTC4360 turns off the N-channel MOSFET rapidly in an
overvoltage event. Figure 7 shows the effects of a voltage
transient at the wall adaptor output V
rent in L
N-channel MOSFET to C
to a voltage of V
WALL ADAPTOR
DSS
AC/DC
+
of the MOSFET. Figure 6 shows a 50V input plugged
20V/DIV
1V/DIV
5A/DIV
IN
I
CABLE
V
OUT
V
will cause V
Figure 6. 50V Hot-Plug into the LTC4360
IN
FDC5612
R
LOAD = 10Ω, C
IN
R
IN
= 150mΩ, L
I
OUT
CABLE
CABLE
L
+ 1.3•(BV
IN
IN
OUT
IN
OUT
= 0.7μH
to overshoot and avalanche the
5μs/DIV
= 10μF
. Typically, IN will be clamped
IN
DSS
Si1470DH
IN
LTC4360
of Si1470DH) = 45V.
GATE
GND
M1
OUT
ADAPTOR
436012 F05
Figure 5. 20V Hot-Plug into the LTC4360
OUT
. The cur-
C
OUT
MOBILE
DEVICE
LOAD
436012 F04a
This is well below the 85V absolute maximum voltage
rating of the LTC4360. The single, nonrepetitive, pulse of
energy (E
lanche breakdown with a peak current I
by the formula:
For L
the I
the Si1470DH. So in most instances, the LTC4360 can
ride through such transients without a bypass capacitor,
transient voltage suppressor or other external components
at IN.
V
E
ADAPTOR
AS
AS
IN
= 0.5 • L
20V/DIV
= 2μH and I
10V/DIV
20A/DIV
and E
5V/DIV
5A/DIV
1V/DIV
I
I
/V
CABLE
CABLE
V
AS
Figure 7. Input Transient After Overvoltage
OUT
OUT
V
V
IN
IN
) absorbed by the MOSFET during this ava-
LTC4360-1/LTC4360-2
AS
R
LOAD = 10Ω, C
FIGURE 5 CIRCUIT
R
LOAD = 10Ω, C
IN
IN
IN
= 150mΩ, L
capabilities of most MOSFET’s including
= 150μΩ, L
V
ADAPTOR
• I
AS
AS
= 4A, then E
2
OUT
OUT
IN
IN
= 2μH
= 0.7μH
5μs/DIV
= 10μF
2μs/DIV
= 10μF
AS
= 16μJ. This is within
V
OUT
AS
436012 F04b
436012 F06
is approximated
436012f
9