Supply Voltage Range (Typical). . . . . . . . . . . . . . . . . . 2.7V to 5.5V
CAUTION: Stresses above those listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation of the
device at these or any other conditions above those indicated in the operational sections of this specification is not implied.
NOTES:
1.
JA
is measured with the component mounted on a high effective thermal conductivity test board in free air. See Tech Brief TB379 for details.
2. All voltages are relative to GND, unless otherwise specified.
Electrical Specifications
PARAMETER
POWER SWITCH
ISL6119 On Resistance at 2.7V
Supply Voltages = 5V, T
A
= T
J
= -40 to 85°C, Unless Otherwise Specified
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX
UNITS
r
DS(ON)_27
r
DS(ON)_33
r
DS(ON)_50
V
OUT_DIS
t_vout_rt
t_svout_offt
t_fvout_offt
VIN = 2.7V I
OUT
= 0.7A T
A
= T
J
= 25°C
T
A
= T
J
= 85°C
VIN = 3.3V, I
OUT
= 0.7A T
A
= T
J
= 25°C
T
A
= T
J
= 85°C
VIN = 5V, I
OUT
= 0.7A T
A
= T
J
= 25°C
T
A
= T
J
= 85°C
VIN = 5V, Switch Disabled, 50A Load
R
L
= 10C
L
= 0.1F, 10%-90%
R
L
= 10C
L
= 0.1F, 90%-10%
R
L
= 1C
L
= 0.1F, 90%-10%
Vout = 0.8V
R
L
= 5C
L
= 0.1F to Within 10% of CR
R
L
< 1C
L
= 0.1F to Within 10% of CR
ISL6119X, Tj = +25°C
-
-
-
-
-
-
-
-
-
-
90
115
80
115
80
115
300
10
10
4
105
130
100
130
95
130
450
-
-
-
m
m
m
m
m
m
mV
V/ms
V/ms
V/s
ISL6119 On Resistance at 3.3V
ISL6119 On Resistance at 5.0V
Disabled Output Voltage
Vout Rising Rate
Slow Vout Turn-off Rate
Fast Vout Turn-off Rate
CURRENT CONTROL
Current Limit, VIN = 3.3V - 5V
OC Regulation Settling Time
Severe OC Regulation Settling Time
Over Current Latch-off Time
I/O PARAMETERS
Fault Output Voltage
ENABLE High Threshold
ENABLE Low Threshold at 2.7V
ENABLE Low Threshold at 5.5V
ENABLE Input Current
BIAS PARAMETERS
Enabled VIN Current
Disabled VIN Current
Undervoltage Lockout Threshold
UV Hysteresis
Over Temperature Disable
Ilim
tsett
Ilim
tsett
Ilim_sev
t
OC_loff
Vfault_hi
Ven_vih
Ven_vil
Ven_vil
Ien_i
0.75
-
-
-
1
2
100
10
1.25
-
-
-
A
ms
s
ms
Fault I
OUT
= 10mA
VIN = 5.5V
VIN = 2.7V
VIN = 5.5V
ENABLE = 0V to 5V, VIN = 5V, T
J
> 25°C
Switches Closed, OUTPUT = OPEN, T
J
> 0°C
Switches Open, OUTPUT = OPEN
VIN Rising, Switch Enabled
-
2.0
-
-
-0.5
-
-
-
-
-
0.4
-
0.6
0.8
0.5
V
V
V
V
A
I
VDD
I
VDD
V
UVLO
UV
HYS
Temp_dis
-
-
1.7
50
-
120
1
2.25
100
150
200
5
2.5
-
-
A
A
V
mV
°C
FN9002 Rev 3.00
March 2004
Page 4 of 13
ISL6119
Introduction
The ISL6119 is a fully independent dual channel overcurrent
(OC) fault protection IC for the +2.5V to +5.5V environment.
Each ISL6119 incorporates in a single 8 lead SOIC package
two 80mW N-channel MOSFET power switches for power
control. Independent enabling inputs and fault reporting
outputs compatible with 3V and 5V logic allows for external
control and monitoring. This device features internal current
monitoring, accurate current limiting, integrated power
switches and current limited timed delay to latch-off for system
protection. See Figure 1 for typical operational waveforms
including both under and overcurrent situations.
Latch-Off Time Delay
The primary function of any OC protection device is to quickly
isolate the voltage bus from a faulty load. Unlike many other IC
products that sense the IC thermal condition (the monitored IC
junction temperature depends on a number of factors the most
important of which are power dissipation of the faulted and
adjacent switches and package temp) to isolate a faulty load,
the ISL6119 uses an internal 12ms timer that starts upon OC
detection. Once an OC condition is detected the appropriate
output is current limited for a maximum of 12ms to allow
transient conditions to pass before latch-off. This time to latch-
off is independent of device thermal or adjacent switch
condition. See Figure 18 for waveforms illustrating
independent latch-off.
If, after the ISL6119 has latched off, and the fault has asserted
and, the enable is not deasserted but the OC condition still
exists, the ISL6119 unlike other IC devices does not send to
the controller a continuous string of fault pulses. The ISL6119’s
single fault signal is sent at the time of latch-off unlike other
devices.
Key Feature Description and Operation
UV Lock Out
The ISL6119 undervoltage lockout feature prevents
functionality of the device unless the correct ENABLE state
and VIN > 2.5V are present.
Soft Start
A constant 500nA current source ramps up the switch’s gate
causing a voltage follower effect on the output voltage. This
provides a soft start turn-on eliminating bus voltage drooping
caused by in-rush current charging heavy load capacitances.
Rising and falling outputs are current limited voltage ramps so
that both the inrush current and voltage slew rate are limited,
independent of load. This reduces supply droop due to surge
and also eliminates the need for EMI filters necessary on other
IC products.
Slow And Fast Shutdown
The ISL6119 has two shutdown modes. When turned off with a
load current less than the current regulation (CR) level the
ISL6119 shuts down in a controlled manner using a 500nA
constant current source controlled ramp. When latched off due
to CR and the timer has expired, the ISL6119 quickly pulls
down the output thereby quickly removing the faulted load from
the voltage bus. See Figures 8 and 9 for waveforms of each
mode.
Fault Blanking On Start-Up
During initial turn-on the ISL6119 prevents nuisance faults
being reported to the system controller by blanking the fault
signal for 12ms. This blanking eliminates the need for external
RC filters necessary for other vendor products that assert a
fault signal upon initial turn-on into a temporary high current
condition. See Figures 10 through 12 for waveform examples.
Active Output Pulldown
Another unique ISL6119 feature is the active pull down on the
outputs to 300mV above GND when the device is disabled.
Competitors’ parts’ switch leakage causes the output voltage to
drift up to VIN voltage even when the part is supposed to be
disabled.
ON
FAULT
ENABLE
RESET BY
ENABLE
CURRENT
REGULATION
SETTLING TIME
(1.4ms)
Current Regulation
The ISL6119 has integrated current sensing on the power
MOSFET that allows for rapid control of OC events. Once an
OC is detected the ISL6119 goes into its current regulation
(CR) control mode. The ISL6119 CR level is set to a nominal
1A. This current regulation is
25%
over the full operating
temperature and voltage bias range. See Figures 4 and 5 for
illustrative curves. The speed of this control is inversely related
to the magnitude of the OC fault. Thus a hard overcurrent is
more quickly controlled than a marginal OC condition. See
Figure 6 for waveforms illustrating this and Figure 7 for an
accompanying graph.
OFF
LATCH-OFF SET
VOUT
OVER CURRENT
1A CURRENT
LIMIT
Over Temperature Shutdown
Although the ISL6119 has a thermal shutdown feature,
because of the 12ms timed shutdown this will only be invoked
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