AIC1526 Analog Intergrations Corporation, AIC1526 Datasheet - Page 7

• Manufacturer Part Number: AIC1526
• Description: Dual USB High-Side Power Switch
• Manufacturer: Analog Intergrations Corporation

Error Flag
Current Limit
Thermal Shutdown
An open-drained output of an N-channel
MOSFET, the FLG output is pulled low to signal
the following fault conditions: input undervoltage,
output current limit, and thermal shutdown.
The current limit threshold is preset internally. It
protects the output MOSFET switches from
damage
conditions or excess inrush current often
encountered during hot plug-in. The low limit of
the current limit threshold of the AIC1526 allows
a minimum current of 0.5A through the MOSFET
switches. A current limit condition will signal the
error flag.
When the chip temperature exceeds 135°C for
any reason other than overcurrent fault of either
one of the two MOSFET switches, the thermal
shutdown function turns off both MOSFET
switches and signal the error flag. A hysteresis of
10°C prevents the MOSFETs from turning back
on until the chip temperature drops to below
125°C. However, if thermal shutdown is triggered
by chip temperature rise due to overcurrent fault
condition of either one of the MOSFET switches,
the thermal shutdown function will only turn off
the switch that is in overcurrent condition and the
other switch can still remain its normal operation.
In other words, the thermal shutdown function of
the two switches is independent of each other in
APPLICATION INFORMATION
due
to
undesirable
short
circuit
Supply Filtering
Transient Droop Requirements
Short Circuit Transient
Printed Circuit Layout
the case of overcurrent fault.
A 0.1µF to 1µF bypass capacitor from IN to GND,
located
recommended to control supply transients.
Without a bypass capacitor, an output short may
cause sufficient ringing on the input (from supply
lead inductance) to damage internal control
circuitry.
USB support dynamic attachment (hot plug-in) of
peripherals. A current surge is caused by the
input capacitance of downstream device. Ferrite
beads are recommended in series with all power
and ground connector pins. Ferrite beads reduce
EMI and limit the inrush current during hot-
attachment by filtering high-frequency signals.
Bulk
transient current needed during a hot-attachment
event. With a 33µF, 16V tantalum or 100µF, 10V
electrolytic
downstream connector per port should provide
transient drop protection.
The power circuitry of USB printed circuit boards
requires a customized layout to maximize
thermal dissipation and to minimize voltage drop
and EMI.
capacitance
near
capacitor
the
provides
device,
mounted
the
AIC1526
is
short-term
close
strongly
to
7