150KHZ 500MA STEP DOWN VOLTAGE REGULATOR

2007-4-9

3/8

FSP3127

FUNCTIONAL BLOCK DIAGRAM

FUNCTIONAL DESCROPTION

Pin Functions

This is the positive input supply for the IC switching regulator. A suitable input bypass capacitor must be present at

this pin to minimize voltage transients and to supply the switching currents needed by the regulator.

Ground

Circuit ground.

Output

a minimum.

Feedback

Senses the regulated output voltage to complete the feedback loop.

ON/OFF

Allows the switching regulator circuit to be shut down using logic level signals thus dropping the total input supply

current to approximately 80 mA. Pulling this pin below a threshold voltage of approximately 1.3V turns the regulator

on, and pulling this pin above 1.3V (up to a maximum of 25V) shuts the regulator down. If this shutdown feature is not

needed, the ON/OFF pin can be wired to the ground pin or it can be left open, in either case the regulator will be in the

ON condition.

TYPICAL APPLICATION CIRCUIT