5

FN9254.0

July 11, 2006

Pin Descriptions

PVIN

Input supply voltage. Connect a 10µF ceramic capacitor to

power ground.

VCC

Supply voltage for internal analog and digital control circuits,

delivered from PVIN. Bypass with 0.1µF ceramic capacitor to

signal ground.

EN

Regulator enable pin. Force this pin above 1.4V enable the

chip. Force this pin below 0.4V shutdown the chip and

discharge output capacitor when driven to low. Do not leave

this pin floating.

POR

200ms timer output. At power-up or EN HI, this output is a

200ms delayed Power-Good signal for the output voltage.

GND

Ground.

PHASE

Switching node connection. Connect to one terminal of

inductor.

PGND

Power ground. Connect all power grounds to this pin.

SGND

Analog ground. SGND and PGND should only have one

point connection.

FB

Buck regulator output feedback. Connect to the output

through a resistor divider for adjustable the output voltage.

Exposed Pad

The exposed pad must be connected to the PGND pin for

proper electrical performance and optimal thermal

performance.

ISL8011