MP1497 – SYNCHRONOUS, STEP-DOWN CONVERTER WITH INTERNAL MOSFETS

MP1497 Rev. 1.05

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7

12/26/2012

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PIN FUNCTIONS

Package

Pin #

Name

Description

1

SS

Soft-Start. Connect an external capacitor to program the soft start time for the switch-

mode regulator.

2

IN

Supply Voltage. The MP1497 operates from a 4.5V-to-16V input rail. Use C1 to decouple

the input rail. Connect using a wide PCB trace.

3

SW

Switch Output. Connect using a wide PCB trace.

4

GND

System Ground. The regulated output voltage reference ground. Connect to GND with

copper and vias.

5

BST

Bootstrap. Connect a capacitor between SW and BST pins to form a floating supply

across the high-side switch driver. A 10Ω resistor placed between SW and BST cap. is

strongly recommended to reduce SW spike voltage.

6

EN/SYNC

Enable/Synchronize. EN high to enable the MP1497. Apply an external clock to change

the switching frequency.

7

VCC

Bias Supply. Decouple with a 0.1μF-to-0.22μF capacitor. Avoid a capacitance that

exceeds 0.22Μf. VCC capacitor should be put closely to VCC pin and GND pin.

8

FB

Feedback. Connect to the tap of an external resistor divider from the output to GND to set

the output voltage. The comparator lowers the oscillator frequency when the FB voltage

drops below 400mV to prevent current-limit run-away during a short-circuit fault.