LTC4413-2 Linear Technology, LTC4413-2 Datasheet - Page 10

• Manufacturer Part Number: LTC4413-2
• Description: Fast Ideal Diodes
• Manufacturer: Linear Technology

LTC4413-1/LTC4413-2
OPERATION
Overcurrent and Short-Circuit Protection
During an overcurrent condition, the output voltage droops
as the load current exceeds the amount of current that
the LTC4413-1/LTC4413-2 can supply. At the time when
an overcurrent condition is fi rst detected, the LTC4413-1/
LTC4413-2 take some time to detect this condition before
reducing the current to I
output is shorted, until TOC, the current may exceed I
The magnitude of this peak short-circuit current can be
large depending on the load current immediately before
the short circuit occurs. During overcurrent operation, the
power consumption of the LTC4413-1/LTC4413-2 is large,
and is likely to cause an overtemperature condition as the
internal die temperature exceeds the thermal shutdown
temperature.
Overtemperature Protection
The overtemperature condition is detected when the
internal die temperature increases beyond 150°C. An
overtemperature condition will cause the gate amplifi ers
(A and B) as well as the two P-channel MOSFETs (PA
and PB) to shut off. When the internal die temperature
cools to below 140°C, the amplifi ers turn on and the
LTC4413-1/LTC4413-2 reverts to normal operation. Note
that prolonged operation under overtemperature condi-
tions degrades reliability.
Overvoltage Protection (LTC4413-2 Only)
An overvoltage condition is detected whenever the
overvoltage input (OVI) pin is pulled above 6V. The con-
dition persists until the OVI voltage falls below 5.6V. The
overvoltage protection (OVP) output is low unless an
overvoltage condition is detected. If an overvoltage condi-
tion is present, the OVP output is pulled up to the voltage
applied to the OVI input. This output signal can be used to
enable or disable an external PFET that is placed between
the input that is the source of the excessive voltage and
the input to the LTC4413-2, thus eliminating the potential
damage that may occur to the LTC4413-2 if its input volt-
age exceeds the absolute maximum voltage of 6V. See
the Applications Information section Dual Battery Load
Sharing with Automatic Switchover to a Wall Adapter with
10
OC
. For short durations after the
OC
.
Overvoltage Protection for more information on using the
overvoltage protection function within the LTC4413-2.
Channel Selection and Status Output
Two active-high control pins independently turn off the two
ideal diodes contained within the LTC4413-1/LTC4413-2,
controlling the operation mode as described by Table 1.
When the selected channel is reverse biased, or the
LTC4413-1/LTC4413-2 is put into low power standby, the
status signal indicates this condition with a low voltage.
Table 1: Mode Control
The function of the STAT pin depends on the mode that
has been selected. Table 2 describes the STAT pin output
current, as a function of the mode selected as well as the
conduction state of the two diodes.
Table 2: STAT Output Pin Function
ENB1
High
High
ENB1
Low
Low
High
High
Low
Low
ENB2
ENB2
High
High
High
High
Low
Low
Low
Low
CONDITIONS
Diode A Forward Bias,
Diode B Forward Bias
Diode A Forward Bias,
Diode B Reverse Bias
Diode A Reverse Bias,
Diode B Forward Bias
Diode A Reverse Bias,
Diode B Reverse Bias
Diode A Forward Bias,
Diode B Disabled
Diode A Reverse Bias,
Diode B Disabled
Diode A Disabled,
Diode B Forward Bias
Diode A Disabled,
Diode B Reverse Bias
Diode A Disabled,
Diode B Disabled
STATE
Diode’OR NB: The Two Outputs are not Connected
Internal to the Device
Diode A = ENABLED, Diode B = DISABLED
Diode A = DISABLED, Diode B = ENABLED
All Off (Low Power Standby)
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STAT
I
I
I
I
I
I
I
I
I
SNK
SNK
SNK
SNK
SNK
SNK
SNK
SNK
SNK
= 0μA
= 0μA
= 11μA
= 11μA
= 0μA
= 11μA
= 0μA
= 11μA
= 11μA
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