Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
Consult LTC Marketing for information on non-standard lead based finish parts.
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/
422412fa
2
LTC4224-1/LTC4224-2
ELECTRICAL CHARACTERISTICS
SYMBOL
Supplies
V
CC
I
CC
V
CC(UVL)
V
CCLO
I
CCLO
V
CCLO(UVL)
External Gate Drive
ΔV
GATE
I
GATE(UP)
I
GATE(DN)
I
GATE(FPD)
Current Limit
ΔV
SENSE(CB)
I
SENSE
Inputs and Outputs
V
ON(TH)
ΔV
ON(HYST)
I
ON(IN)
V
OL
Delay
t
CB
t
PHL(SENSE)
t
PLH(GATE)
t
PLH(UVL)
t
D(UV)
t
D(COOL)
t
BLANK
Circuit Breaker Delay
Sense Voltage, (V
CCn
– SENSEn) High to
GATE Low
ONn
Low or Input Supply High to GATEn
High Prop Delay
V
CCn
Low to GATEn Low Prop Delay
UV Turn-On Delay
Auto-Retry Cooling Delay
Start-Up Circuit Breaker Blanking Delay
V
CC
Out of UV
Note 3
ΔV
SENSE
= 200mV, C
GATE
= 10nF
l
l
l
l
l
l
l
The
l
denotes the specifications which apply over the full operating
temperature range. T
A
= 25°C, V
CC1
= 5V, V
CC2
= 3.3V, unless otherwise noted.
PARAMETER
V
CC
Supply Range
V
CC
Supply Current
V
CC
Undervoltage Lockout
V
CCLO
Supply Range
V
CCLO
Supply Current
V
CCLO
Undervoltage Lockout
Gate Drive
(V
GATEn
– V
CC
)
Gate Pull-Up Current
Gate Pull-Down Current
Gate Fast Pull-Down Current
Circuit Breaker Trip Sense Voltage
(V
CCn
– SENSEn)
SENSE Input Current
ONn
Threshold Voltage
ONn
Hysteresis
ONn
Pull-Up Current
Output Low Voltage (FAULT)
V
ONn
= 1V
I
FAULT
= 3mA
V
SENSE1
= 5V, V
SENSE2
= 3.3V
V
ONn
Rising
V
CCLO
Falling
I
GATEn
= 0μA, –1μA
Gate Drive On, V
GATEn
= 1V
V
ONn
= 1V, V
GATEn
= 10V
Fast Turn-Off, V
GATEn
= 10V
V
CC
Rising
V
CCLO
= Min (V
CC1
, V
CC2
),
V
CC
≥ 2.7V
CONDITIONS
V
CC
= Max (V
CC1
, V
CC2
)
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
MIN
2.7
TYP
MAX
6
UNITS
V
mA
V
V
μA
V
V
μA
mA
mA
mV
μA
V
mV
μA
V
ms
μs
ms
μs
ms
s
ms
1.4
2.2
1
40
0.76
4.5
–7
0.5
50
22.5
0.8
5.5
–10
1.5
125
25
40
0.76
15
–5
0.8
30
–10
0.2
2.5
5
0.4
5
10
8
80
2
2.5
160
4
5
2.4
3
2.65
6
100
0.84
7
–13
3
200
27.5
100
0.84
50
–15
0.4
7.5
1
15
16
240
6
7.5
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 device pins are positive; all currents out of device
pins are negative. All voltages are referenced to GND unless otherwise
specified.
Note 3:
LTC4224-2 only.
Note 4:
The greater of V
CC1
and V
CC2
is the internal supply voltage (V
CC
).
An internal clamp limits the GATE pin to a minimum 5V above V
CC
. Driving
this pin beyond the clamp may damage the device.
422412fa
3
LTC4224-1/LTC4224-2
TYPICAL PERFORMANCE CHARACTERISTICS
Specifications are T
A
= 25°C, V
CC1
= 5V, V
CC2
= 3.3V, unless otherwise specified.
I
CC
vs V
CC
1.5
26.0
25.5
25.0
V
CB
(mV)
I
CC
(mA)
24.5
24.0
1.1
23.5
23.0
5.1
t
CB
(ms)
1
2
3
V
CC
(V)
422412 G01
422412 G02
Circuit Breaker Trip Voltage
vs V
CC
5.5
Circuit Breaker Delay vs V
CC
1.4
5.4
1.3
5.3
1.2
5.2
1.0
2.5
3
3.5
4.5
4
V
CC
(V)
5
5.5
6
4
5
6
5.0
2.5
3
3.5
4
4.5
V
CC
(V)
5
5.5
6
422412 G03
Gate Drive vs I
GATE
6
5
4
ΔV
GATE
(V)
ΔV
GATE
(V)
3
2
1
0
5.65
5.60
5.55
5.50
5.45
5.40
Gate Drive vs Temperature
GATE NORMAL PULL-DOWN CURRENT (mA)
2.0
Gate Pull-Down Current
vs Gate Voltage
1.8
1.6
1.4
1.2
0
–2
–4
–6
–8
I
GATE
(μA)
–10
–12
422412 G04
5.35
–50
1.0
–25
0
25
50
TEMPERATURE (°C)
75
100
422412 G05
8
9
10
11
V
GATE
(V)
12
13
422412 G06
Gate Fast Pull-Down Current
vs Gate Voltage
150
GATE FAST PULL-DOWN CURRENT (mA)
ACTIVE CURRENT LIMIT DELAY (μs)
1.5
Active Current Limit Delay
vs Sense Voltage
500
FAULT
Voltage
vs
FAULT
Sink Current
140
1.2
400
T = 90°C
V
OL
(mV)
130
0.9
300
T = 25°C
200
T = –60°C
120
0.6
110
0.3
100
100
8
9
10
11
V
GATE
(V)
12
13
422412 G07
0.0
25
50
75
100
125
SENSE VOLTAGE (mV)
150
422412 G08
0
0
1
2
3
I
FAULT
(mA)
4
5
422412 G09
422412fa
4
LTC4224-1/LTC4224-2
PIN FUNCTIONS
SENSE1, SENSE2 (Pins 1,10):
Current Sense Input. Con-
nect this pin to an external sense resistor. The current limit
circuit controls GATEn to limit the voltage between V
CCn
and SENSEn to 25mV. An Electronic Circuit Breaker (ECB)
is active during current limiting and trips after 5ms. To
disable current limit, connect this pin to V
CCn
.
V
CC1
, V
CC2
(Pins 2, 9):
Supply Voltage and Current Sense
Input. An undervoltage lockout circuit disables the part
until V
CC
, the higher of V
CC1
and V
CC2
, exceeds 2.4V. The
lower supply is disabled until it exceeds 0.8V.
GATE1, GATE2 (Pins 3, 8):
Gate Drive for External N-channel
MOSFET. A charge pump sources 10μA from GATE to turn
on the external MOSFET. An internal clamp limits the gate
voltage to 5.5V above the higher of V
CC1
and V
CC2
. During
turn-off, a 1.5mA pulldown current discharges GATE to
ground. During short-circuits, a 125mA pulldown current
is activated to discharge GATE to ground.
FAULT
(Pin 4):
Fault Status Output. Open-drain output
that is normally pulled high to V
CC1
or V
CC2
by an exter-
nal resistor. It is pulled low when the ECB trips due to an
overcurrent condition at either supply. This pin may be
left open if unused.
ON1, ON2
(Pins 5, 6):
On Control Input. A falling edge
turns on the external N-channel MOSFET and a rising edge
turns it off. A low to high transition on this pin resets an
ECB fault for the corresponding channel. Internally pulled
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