AIC6186 Datasheet, PDF (7/9 Pages) Analog Intergrations Corporation – 0.5A Dual USB High-Side Power Switch

AIC6186
 APPLICATION INFORMATION
 Flag Output
An error Flag is an open-drained output of an
N-channel MOSFET. Flag output is pulled low to
signal the following fault conditions: input under
voltage, output current limit, and thermal
shutdown. The current limit flag response delay
time is 9ms.
 Current Limit
The current limit threshold is preset internally. It
protects the output MOSFET switches from
damage resulting from undesirable short circuit
conditions or excess inrush current, which is often
encountered during hot plug-in. The error flag
signals when any current limit conditions occur.
 Thermal Shutdown
When temperature of AIC6186 exceeds 150C for
any reasons, the thermal shutdown function turns
MOSFET switch off and signals the error flag. A
hysteresis of 30C prevents the MOSFETs from
turning back on until the chip temperature drops
below 120C.
 Enable Control
Enable must be driven logic high or logic low for a
clearly defined input. Floating the input may cause
unpredictable operation.
 Under-voltage Lockout
UVLO (under voltage lockout) prevents the output
MOSFET from turning on until input voltage
exceeds 2.3V typically. After the switch turns on, if
the input voltage drops below 2.1V typically,
UVLO shuts off the output MOSFET.
 Supply Filtering
A 1F bypass capacitor from USB IN to GND,
located near the device, is strongly 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.
 Transient Requirements
USB supports 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.
 Short Circuit Transient
Bulk capacitance provides the short-term transient
current needed during a hot-attachment event. A
10F/10V ceramic capacitor mounted close to
downstream connector each port should provide
transient drop protection.
 Printed Circuit Layout
The power circuitry of USB printed circuit boards
requires a customized layout to maximize thermal
dissipation and to minimize voltage drop and EMI.
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