LTC4219IDHC-12#TRPBF Linear Technology, LTC4219IDHC-12#TRPBF Datasheet - Page 8

• Manufacturer Part Number: LTC4219IDHC-12#TRPBF
• Description: IC CONTROLLER HOT SWAP12A 16DFN
• Manufacturer: Linear Technology
• Type: Hot-Swap Switchr

Specifications of LTC4219IDHC-12#TRPBF

• Applications: General Purpose
• Internal Switch(s): Yes
• Current Limit: 5.6A
• Voltage - Supply: 2.9 V ~ 15 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 16-WFDFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

PIN FUNCTIONS
LTC4219
EN1: Inverted Enable 1 Input. Ground this pin to enable
the MOSFET to turn on after 100ms debounce delay. If
the voltage at this pin rises above 1.235V for longer than
10μs a turn-off command is detected, the overcurrent
fault is cleared and the MOSFET gate is discharged with
a 250μA current. Bringing this pin below 1.15V and EN2
low for 100ms begins GATE pin ramping.
EN2: Inverted Enable 2 Input. Ground this pin to enable
the MOSFET to turn on after 100ms debounce delay. If
the voltage at this pin rises above 1.235V for longer than
10μs a turn-off command is detected and the MOSFET
gate is discharged with a 250μA current. Bringing this
pin below 1.15V and EN1 low for 100ms begins GATE
pin ramping.
Exposed Pad: SENSE.
FB: Foldback and Power Good Input. The FB pin is driven
from an internal resistive divider from OUT for both the
LTC4219-12 and LTC4219-5. These versions preset 12V
and 5V foldback and power good levels. If the OUT volt-
age falls below 2.5V (LTC4219-5) or 6V (LTC4219-12)
the current limit is reduced using a foldback profi le (see
the Typical Performance Characteristics section). If the
FB voltage falls below 1.21V the PG pin will pull high to
indicate the power is bad.
FLT: Overcurrent Fault Indicator. Open-drain output pulls
low when an overcurrent fault has occurred and the circuit
breaker trips.
GATE: Gate Drive for Internal N-channel MOSFET. An
internal 24μA current source charges the gate of the
N-channel MOSFET. At start-up the GATE pin ramps up at
a 0.3V/ms rate determined by internal circuitry. During an
undervoltage or overvoltage condition a 250μA pull-down
current turns the MOSFET off. During a short-circuit or
undervoltage lockout condition, a 140mA pull-down current
source between GATE and OUT is activated.
GND: Device Ground.
I
MOSFET switch is divided by 50,000 and sourced from
this pin. Placing a 20k resistor from this pin to GND cre-
ates a 0V to 2V voltage swing when current ranges from
0A to 5A.
8
MON
: Current Monitor Output. The current in the internal
INTV
must have a 0.1μF or larger bypass capacitor.
I
value open this pin. This pin is driven by a 20k resistor
in series with a voltage source. The pin voltage is used
to generate the current limit threshold. The internal 20k
resistor and an external resistor between I
create an attenuator that lowers the current limit value.
In order to match the temperature variation of the sense
resistor, the voltage on this pin increases at the same rate
as the sense resistance increases. Therefore the voltage
at I
switch.
OUT: Output of Internal MOSFET Switch. Connect this
pin directly to the load. An internal resistive divider is
connected to this pin to drive the FB pin.
PG: Power Good Indicator. Open-drain output releases
the PG pin to go high when the FB pin drops below 1.21V
indicating the power is bad. If the FB pin rises above 1.23V
and the GATE to OUT voltage exceeds 4.2V, the open-drain
output pulls low indicating power is good.
SENSE: Current Sense Node and MOSFET Drain. The cur-
rent limit circuit controls the GATE pin to limit the sense
voltage between the V
or less depending on the voltage at the FB pin. The exposed
pad on the DHC package is connected to SENSE and must
be soldered to an electrically isolated printed circuit board
trace to properly transfer the heat out of the package.
TIMER: Timer Input. Connect a capacitor between this pin
and ground to set a 12ms/μF duration for current limit
before the switch is turned off. If the EN1 pin is toggled
fi rst high then low while the MOSFET switch is off, the
switch will turn on again following a cooldown time of
518ms/μF duration. Tie this pin to INTV
overcurrent delay.
V
has an undervoltage lockout threshold of 2.73V.
SET
DD
SET
: Current Limit Adjustment Pin. For a 5.6A current limit
: Supply Voltage and Current Sense Input. This pin
CC
pin is proportional to temperature of the MOSFET
: Internal 3V Supply Decoupling Output. This pin
DD
and SENSE pins to 42mV (5.6A)
CC
SET
for a fi xed 2ms
and ground
4219fb