LTC4219
7
4219fd
For more information www.linear.com/LTC4219
Typical perFormance characTerisTics
Gate Drive vs
Gate Pull-Up Current
T
A
= 25°C, V
DD
= 12V unless otherwise noted.
Gate Drive vs V
DD
Gate Drive vs Temperature
V
ISET
vs Temperature
I
GATE
(µA)
0
0
∆V
GATE
(V
GATE
– V
OUT
) (V)
7
6
5
4
3
2
1
–5 –10 –15 –20
4219 G16
–25 –30
V
DD
(V)
0
6.2
6.0
5.8
5.6
5.4
5.2
5 10 15
4219 G17
20 25 30
∆V
GATE
(V
GATE
– V
OUT
) (V)
TEMPERATURE (°C)
–50
6.15
6.14
6.13
6.12
6.11
6.10
–25 0 25
4219 G18
50 75 100
∆V
GATE
(V
GATE
– V
OUT
) (V)
TEMPERATURE (°C)
–50
0.9
0.8
0.7
0.6
0.5
0.4
0.3
–25 0 25
4219 G19
50 75 150125100
V
ISET
(V)
LTC4219
8
4219fd
For more information www.linear.com/LTC4219
pin FuncTions
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 profile (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.
F LT : 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 inter
-
nal 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. When either EN1 or
EN2 pin goes high, 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
MON
: Current Monitor Output. The current in the internal
MOSFET switch is divided by 50,000 and sourced from this
pin. Placing a 20k resistor from this pin to GND creates a
0V to 2V voltage swing when current ranges from 0A to 5A.
INTV
CC
: Internal 3V Supply Decoupling Output. This pin
must have a F or larger bypass capacitor. Overloading
this pin can disrupt internal operation.
I
SET
: Current Limit Adjustment Pin. For a 5.6A current limit
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 (R
ISET
) and an external resistor (R
SET
) between
I
SET
and ground create an attenuator that lowers the cur-
rent limit value. Due to circuit tolerance R
SET
should not be
less than 2k. 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
SET
pin is proportional to temperature of
the MOSFET switch.
OUT: Output of Internal MOSFET Switch. Connect this pin
directly to the load. An internal resistive divider is con
-
nected 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
DD
and SENSE pins to 42mV (5.6A)
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
first 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
CC
for a fixed 2ms
overcurrent delay.
V
DD
: Supply Voltage and Current Sense Input. This pin
has an undervoltage lockout threshold of 2.73V.
LTC4219
9
4219fd
For more information www.linear.com/LTC4219
FuncTional Diagram
4219 BD
V
DD
EN1
OUT
FB
PG
GND
I
MON
INTV
CC
INTV
CC
100µA
TIMER
F LT
+
I
SET
R
ISET
20k
GATE
6.15V
SENSE
(EXPOSED PAD)
X1
CLAMP
0.6V POSITIVE
TEMPERATURE
COEFFICIENT
REFERENCE
INTERNAL 25mΩ
MOSFET
INTERNAL 7.5mΩ
SENSE RESISTOR
CHARGE
PUMP
AND GATE
DRIVER
f = 2MHz
OUT
3.1V
GEN
LOGIC
INRUSHCS
CM
0.3V/ms
FOLDBACK
0.6V
2.65V
1.235V
+
+
PG
1.235V
+
EN1
0.21V
+
TM1
1.235V
+
TM2
1.235V
+
EN2
V
DD
V
DD
2.73V
+
UVLO1
EN2
2µA
+
UVLO2
OUT
* 100k (LTC4219-5)
150k (LTC4219-12)
** 40k (LTC4219-5)
20k (LTC4219-12)
*
**

LTC4219IDHC-5#TRPBF

Mfr. #:
Manufacturer:
Analog Devices Inc.
Description:
Hot Swap Voltage Controllers 5V, 5A Integrated Hot Swap Controller
Lifecycle:
New from this manufacturer.
Delivery:
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