The package of AX3803 is SOP-8L-EP; the pin assignment is given by:
High-Side Gate Drive Boost Input. BS
supplies the drive for the high-side
BS N-Channel MOSFET switch. Connect a
0.01μF or greater capacitor from SW to
BS to power the high side switch.
Power Input. IN supplies the power to
the IC, as well as the step-down
converter switches. Drive IN with a
IN 4.75V to 23V power source. Bypass IN
( Top View )
to GND with a suitably large capacitor
to eliminate noise on the input to the IC.
See Input Capacitor.
Power Switching Output. SW is the
switching node that supplies power to
the output. Connect the output LC filter
from SW to the output load. Note that a
capacitor is required from SW to BS to
power the high-side switch.
Feedback Input. FB senses the output
voltage to regulate that voltage. Drive
FB with a resistive voltage divider from
the output voltage. The feedback
threshold is 0.925V. See Setting the
NC Not connect
Enable Input. EN is a digital input that
turns the regulator on or off. Drive EN
EN high to turn on the regulator, drive it low
to turn it off. Pull up with 100kΩ resistor
for automatic startup.
AX3803 XX X
Package Type Packing
ES: SOP-8L-EP Blank: Tube
A : Taping
AX 3 8 0 3
Y Y W WX
Axelite Confidential Materials, do not copy or distribute without written consent.
Rev.1.0 Nov.22, 2012