ISL6185_14 Datasheet, PDF (10/20 Pages) Intersil Corporation – Dual USB Port Power Supply Controller

ISL6185
Turn-off Time Delay
During operation, once an OC condition is detected, the output
is current limited for ~12ms to allow transient OC conditions to
pass. If still in current limit and after the current limit period
has elapsed, the output is turned off, and the fault is reported
by pulling the corresponding FAULT low. The internal 12ms timer
starts upon current limiting and is independent of ambient or IC
thermal conditions, thus providing more consistent operation
over the entire temperature range.
Typical Performance Curves
150
140
130
120
V_IN = 2.5V
110
100
90
V_IN = 3.3V
80
70
60
50
-40 -25
V_IN = 5V
0 25 45 75
TEMPERATURE (°C)
85 115
FIGURE 3. SWITCH ON-RESISTANCE AT 0.5A
Latch-off Restart/Auto-Restart Start
After turn-off, with the latch-off options, both the output and the
FAULT signal are latched low until they are reset by the enable
signal being de-asserted. At this time, the FAULT signal clears,
and the IC is ready for enable to assert. On the auto restart
options, the ISL6185 attempts to periodically turn-on the
output at approximately 1s intervals, as long as the enable is
asserted. If the OC condition remains indefinitely, the fault
indication and the restart attempts also continue until the
thermal protection feature is invoked, thus increasing the
restart period.
Active Output Pull-down
Another ISL6185 feature is the 10kΩ active pull-down on the
outputs to <60mV above GND when the device is disabled, thus
ensuring discharge of the load.
1.3
1.2
1.1
1.0
0.9
0.8
0.7
-40 -25
0 25 45 75
TEMPERATURE (°C)
85 115
FIGURE 4. NORMALIZED SWITCH RESISTANCE
1.2
5V I_TRIP
1.1
1.0
0.9 ^{3.3V I}TRIP
0.8
0.7 ^{5V ISC}
5V I_LIM
0.6
3.3V I_LIM
0.5
0.4
-40 -25
3.3V I_SC
0 25 45 75
TEMPERATURE (°C)
85 115
FIGURE 5. 0.6A CONTINUOUS CURRENT CHARACTERISTICS
1.6
1.5
1.4 ^{5V ITRIP}
1.3 ^{3.3V I}TRIP
5V I_SC
1.2
1.1 ^{5V ILIM}
1.0 3.3V I_LIM
0.9
0.8
3.3V I_SC
0.7
0.6
-40 -25
0 25 45 75
TEMPERATURE (°C)
85 115
FIGURE 6. 1.1A CONTINUOUS CURRENT CHARACTERISTICS
10
FN6937.3
March 8, 2012