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4

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January 2011

Rev. 1.1.0

Exar Corporation

www.exar.com

48720 Kato Road, Fremont CA 94538, USA

Tel. +1 510 668-7000 – Fax. +1 510 668-7001

GENERAL DESCRIPTION

The XRP6124 is a non synchronous step down

(buck) controller for up to 5Amps point of

loads. A wide 3V to 30V input voltage range

allows for single supply operations from

industry standard 3.3V, 5V, 12V and 24V

power rails.

With a proprietary Constant On-Time (COT)

control

scheme,

the

XRP6124

provides

extremely fast line and load transient response

while the operating frequency remains nearly

constant. It requires no loop compensation

hence simplifying circuit implementation and

reducing

overall

component

count.

The

XRP76124 also implements an emulated ESR

circuitry allowing usage of ceramic output

capacitors and insuring stable operations

without the use of extra external components.

Built-in soft start prevents high inrush currents

while under voltage lock-out and output short

protections insure safe operations under

abnormal operating conditions.

The XRP6124 is available in a RoHS compliant,

green/halogen free space-saving 5-pin SOT23

package.

APPLICATIONS

• Point of Load Conversions

• Audio-Video Equipments

• Industrial and Medical Equipments

• Distributed Power Architecture

FEATURES

• 5A Point-of-Load Capable

− Down to 1.2V Output Voltage Conversion

• Wide Input Voltage Range

− 3V to 18V: XRP6124

− 4.5V to 30V: XRP6124HV

• Constant On-Time Operations

− Constant Frequency Operations

− No External Compensation

− Supports Ceramic Output Capacitors

• Built-in 2ms Soft Start

• Short Circuit Protection

• <1µA shutdown current

• RoHS Compliant, Green/Halogen Free

5-pin SOT23 Package

TYPICAL APPLICATION DIAGRAM

Figure 1: XRP6124 Application Diagram