AAT4601 Datasheet, PDF (7/14 Pages) Advanced Analogic Technologies – 1.5A Current Limited P-Channel Switch

Functional Block Diagram
AAT4601
1.5A Current Limited P-Channel Switch
IN
Under-
voltage
Lockout
Over-temp
Protection
ON
1.2V
Reference
Current
Limit
OUT
FAULT
SET
Functional Description
The AAT4601 is an integrated MOSFET load
switch with an adjustable current limit, over tem-
perature protection, level shifted input and a fault
flag. The current limit control is combined with an
over temperature thermal limit circuit to provide a
comprehensive system to protect the load switch
under short circuit or other adverse operating con-
ditions. The AAT4601 is ideally suited for control
and protection of peripheral ports such as USB,
RS232 and parallel ports.
The current limit and over temperature circuits will
act independently. The device current limit is acti-
vated when the output load current exceeds an
internal threshold level. The internal current limit
threshold is determined by an external resistor
connected between the SET pin and ground. The
minimum current limit threshold is specified by
I_LIM(MIN). If the load switch ambient temperature
becomes excessive or if a short circuit condition
4601.2001.11.0.92
persists, the die temperature will rise causing the
over temperature protection circuit to activate.
If the current limit or over temperature protection
circuits are active for more then two milliseconds,
the system will be informed via the FAULT Flag.
The two millisecond delay allows the AAT4601 to
be turned on into capacitive loads without activat-
ing the FAULT Flag. The open drain FAULT output
can be connected directly to system controllers
driven by voltage levels less than the IN pin voltage
without additional level shifting circuitry.
The load switch is turned off by applying a logic high
level to the ON pin. The AAT4601 typically con-
sumes 12µA when operating, when off, the device
draws less then 1µA. In the off state, current is pre-
vented from flowing between the input and output.
The ON function has logic level thresholds that
allow the AAT4601 to be TTL compatible and may
also be controlled by 2.5V to 5.0V CMOS circuits.
The voltage level on either ON or FAULT should not
exceed the input supply level present on the IN pin.
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