AIC1523
PIN DESCRIPTION
PIN 1/4/6/8: NC:
n
PIN 3: IN-
Power supply input.
PIN 2: CTL
- TTL compatible control input. It
controls the power switch turn-
on/turn-off. Active High for
PIN 4: GND-
PN 7: OUT-
Chip power ground.
MOSFET switch output.
AIC1523-1 and active low for
AIC1523-0.
APPLICATION INFORMATIONS
Current Limit
n
l
Transient Droop Requirements
l
l The current limit threshold is preset internally. It
protects the output MOSFET switches from
damage due to undesirable short circuit
conditions or excess inrush current often
encountered during hot plug-in. The AIC1523
allows minimum 500mA continuous load current
per Channel.
A current surge is caused by the input capacitance
of 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
l
l
Thermal Protection
When the chip temperature exceeds 110°C, the
thermal protection function works.
l
Bulk capacitance provides the short-term transient
current needed during a hot-attachment event. With
a 33uF, 16V tantalum or 100uF, 10V electrolytic
capacitor mounted close to downstream connector
should provide transient drop protection.
Supply Filtering
l
A 0.1uF to 1uF bypass capacitor from 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.
Printed Circuit Layout
The power circuitry of
printed circuit boards
requires a customized layout to maximize thermal
dissipation and to minimize voltage drop and EMI.
7
AIC [ ANALOG INTERGRATIONS CORPORATION ]
