SC3203

10

Pin Descriptions

Pin #

Pin Name

Pin Function

1

EN

Enable input for switching regulator —Pull EN high to enable the LDO and PWM. Connect to PGND to disable

the PWM. Connect a resistor divider from VIN to program the external VIN Under-voltage threshold.

2

BST

Boost Supply pin — Connect a 10nF capacitor between BST and LX to develop the floating voltage for the

high-side gate drive.

3

LX

Switching (phase) node. LX is also the sense point for the Zero Current Detector.

4

VIN

Power input for the High Side Mosfet and for the input to the LDO. VIN is the also sense point for the internal

VIN Under-voltage Lockout and the VIN input for the On-time Generator.

5

AGND

Ground for the internal analog circuitry. Connect this directly to the PAD for the PGND connection.

6

BYP

Bypass pin for the internal 5V LDO which supplies bias voltage for the analog and gate drive circuits— A 1uF

decoupling capacitor is required — The LDO is enabled when the EN pin exceeds typically 1V.

7

PGOOD

Open-drain Power Good output.

8

VFB

Feedback input — Connect this pin to a resistor/capacitor divider between the output voltage and AGND.

See the Table on the Typical Application Circuit for recommended values.

PAD

PGND

Power ground connection. PAD is ground for the power circuits of the IC. The PGND pad should connect

directly to the AGND pin, see Layout Guidelines.