AT9919 datasheet(9/16 Pages) MICROCHIP

Teilenummer	AT9919

Bauteilbeschribung	Hysteretic Buck High-Brightness LED Driver with High-Side Current Sensing

PDF	16 Pages

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Hersteller	MICROCHIP [Microchip Technology]

Direct Link	http://www.microchip.com

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 2016 Microchip Technology Inc.

DS20005595A-page 9

AT9919

3.11

PCB Layout Guidelines

Careful PCB layout is critical to achieving low switching

losses and stable operation. Use a multilayer board

whenever possible for better noise immunity. Minimize

ground noise by connecting high-current ground

returns, the input bypass capacitor ground lead and the

output filter ground lead to a single point (star ground

configuration). The fast di/dt loop is composed of the

input capacitor CIN, the freewheeling diode and the

MOSFET. To minimize noise interaction, this loop area

should be as small as possible. Place RSENSE as close

as possible to the input filter and VIN. For better noise

immunity,

Kelvin

connection

strongly

recommended between CS and RSENSE. Connect the

exposed tab of the IC to a large area ground plane for

improved power dissipation.

AT9919 Datenblatt(PDF) 9 Page - Microchip Technology