MP2380 – 5A, 21V, 600KHz STEP-DOWN CONVERTER

MP2380 Rev.1.2

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3

5/26/2008

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PIN FUNCTIONS

Pin #

Name

Description

1

SW

Switch Output.

2

BST

Bootstrap. This capacitor is needed to drive the power switch’s gate above the supply

voltage. It is connected between SW and BS pins to form a floating supply across the power

switch driver.

3

VCC

Bias Supply. Decouple this pin with a 1µF ceramic capacitor.

4

GND

Ground. This pin is the voltage reference for the regulated output voltage. For this reason

care must be taken in its layout. This node should be placed outside of the D1 to C1 ground

path to prevent switching current spikes from inducing voltage noise into the part.

5

FB

Feedback. An external resistor divider from the output to GND, tapped to the FB pin sets

the output voltage. To prevent current limit run away during a short circuit fault condition the

frequency foldback comparator lowers the oscillator frequency when the FB voltage is

below 250mV.

6

PG

output of this pin is low if the output voltage is 10% less than the nominal voltage, otherwise

it is an open drain.

7

EN/SYNC On/Off Control Input and Synchronization Pin.

8

IN

Supply Voltage. The MP2380 operates from a +4.5V to +21V unregulated input. C1 is

needed to prevent large voltage spikes from appearing at the input.