10

SC3303

10

Pin Descriptions

Pin #

Pin Name

Pin Function

1

BST

Bootstrap pin — A capacitor is connected between BST and LX to develop the floating voltage for the

high-side gate drive.

2

VIN

Power input supply voltage

3

LX

Switching (phase) node

4

PGND

Power ground

5

PGOOD

Open-drain power good indicator — High impedance indicates power is good. An external pull-up

resistor is required.

6FB

Feedback input for switching regulator — Connect to an external resistor divider from the output to pro-

gram the output voltage.

7EN

Enable input for switching regulator —Pull EN high to enable the part with ultrasonic power save mode en-

abled. Connect to AGND to disable the switching regulator. A voltage divider can be added between VIN and

AGND pins for input UVLO functionality.

8

TON

On-time set input — Set the on-time by connecting a series resistor to AGND.

9

AGND

Analog Ground.

10

LDO

Output for the internal LDO and internal connection to the bias node — Decoupling capacitors are required

to AGND and PGND regardless of the use of the LDO for external loads.

PAD

Thermal pad for heat-sinking purposes. (Not connected internally) Connect to AGND plane using multiple

vias.