MP2494 –2A, 55V, 100kHz STEP-DOWN CONVERTER

MP2494 Rev. 1.0

www.MonolithicPower.com

4

4/25/2012

MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.

© 2012 MPS. All Rights Reserved.

PIN FUNCTIONS

Package

Pin #

Name

Description

1

VIN

Supply Voltage. The MP2494 operates from a +4.5V to +55V unregulated input. CIN is

needed to prevent large voltage spikes from appearing at the input. Put CIN as close to

the IC as possible. It is the drain of the internal power device and power supply for the

whole chip.

2

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 CIN

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

3

EN

On/Off Control Input.

4

FB

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

voltage. It is pulled up to 4V power supply internally by a 2Meg resistor.

5

SS

Connect to an external capacitor used for Soft-Start.

6

GS

Ground Sense Input. Connect to ground.

7

BST

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

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

power switch driver. An on-chip regulator is used to charge up the external boot-strap

capacitor. If the on-chip regulator is not strong enough, one optional diode can be

connected from IN or OUT to charge the external boot-strap capacitor.

8

SW

Switch Output. It is the source of power device.