© 2010 Semtech Corporation

Pin Descriptions (MLPD-10)

Pin #

Pin Name

Pin Function

1

BST

Bootstrap pin. A capacitor is connected between BST to 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.

6

FB

Feedback input for switching regulator. Connect to an external resistor divider from the output to

program the output voltage.

7

EN

Enable input for the switching regulator. Pull EN above 1V or float it to enable the part with auto-

matic power save mode enabled. Connect EN to AGND to disable the switching regulator.

8

TON

9

AGND

Analog Ground.

10

VDD

Input power for internal control circuit. Needs at least 2.2mF decoupling capacitor from this pin to

AGND.

PAD

Thermal pad for heatsinking purposes. Connect to ground plane using multiple vias. Not con-

nected internally.

6

SC173A