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10.3.5. Electrical Characteristics
10.3.6. Pinning
Pin1:BS
High-Side Gate Drive Boost Input. BS supplies the drive for the high-side N-Channel
MOSFET switch. Connect a 10nF or greater capacitor from SW to BS to power the high
side switch.
Pin2:IN
Power Input. IN supplies the power to the IC, as well as the step-down converter
switches. Drive IN with a 4.75V to 28V power source. Bypass IN to GND with a suitably
large capacitor to eliminate noise on the input to the IC.
Pin3:SW
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
.
Pin4:GND
Ground.
Pin5:FB
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 1.222V.
Pin6:COMP
Compensation Node. COMP is used to compensate the regulation control loop. Connect
a series RC network from COMP to GND to compensate the regulation control loop. In
some cases, an additional capacitor from COMP to GND is required.
Pin7:EN
Enable Input. EN is a digital input that turns the regulator on or off. Drive EN high to turn
on the regulator, drive EN low to turn it off. An Under Voltage Lockout (UVLO) function
can be implemented by the addition of a resistor divider from VIN to GND. For complete
low current shutdown its needs to be less than 0.7V. For automatic startup, leave EN
unconnected.
Pin8:SS
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