Datasheet

V
OUT
I
OUT
Hard Short
Detection
A hard short occurs on
Vout
V is tied directly to V
ON IN
Current increases
through switch
proportional to V
OUT
t
PWRON
V /2
IN
V /2
OUT
V
IN
0V
V
ON
0V
Over current due to hard
short
Current is
limited
No current.
Switch is off
Over Temperature
Detection
t
OVRTMP
ON
OFF
0.125mS
OFF
OFF
OFF
ON
ON
t
BLANK t
RSTART
Hard short detected during the ON cycle
t
BLANK t
RSTART
t
RSTARTt
BLANK
t
BLANK
t
RSTART
Inrush Current window
8 ms
t
HARDSHORT
t
TIMEOUT
SWITCH
OPEN
SWITCH
CLOSE
SWITCH
OPEN
SWITCH
OPEN
SWITCH
CLOSE
Load Switch Status
TPS22946
SLVS984A –SEPTEMBER 2009–REVISED FEBRUARY 2010 www.ti.com
Hard-Short Detection
The hard short detection circuit is active every 250 ms for a period of 125 ms A comparator monitors the output
voltage, V
OUT
. A hard short is detected when V
OUT
is lower than 2/3 V
IN
. The switch then goes into
current-limiting mode.
Figure 27. Hard-Short Detection
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