MP6903

Fast Turn-off Intelligent Controller

MP6903 Rev. 1.04

www.MonolithicPower.com

1

1/31/2013

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

© 2013 MPS. All Rights Reserved.

The Future of Analog IC Technology

DESCRIPTION

The MP6903 is a low-drop diode emulator that,

combined with an external switch, replaces

Schottky

diodes

in

high-efficiency

LLC

converters. The chip regulates the forward drop

of an external switch to about 70mV and

switches it off as soon as the voltage goes

negative. MP6903 has a light-load sleep mode

that reduces the quiescent current to < 300µA.

FEATURES

 Works with Standard and Logic-Level FETS

 Compatible with Energy Star, 1W Standby

Requirements

 Fast Turn-Off: Total Delay of 20ns

 Max 400kHz Switching Frequency

 <300µA Quiescent Current in Light Load

Mode

 Supports DCM, CCM and CrCM Operation

 Supports High-Side and Low-Side

Rectification

 Power Savings of Up to 1.5W for a Typical

Notebook Adapter

APPLICATIONS

 Industrial Power Systems

 Distributed Power Systems

 Battery Powered Systems

 LLC Converters

All MPS parts are lead-free and adhere to the RoHS directive. For MPS green

status, please visit MPS website under Products, Quality Assurance page.

“MPS” and “The Future of Analog IC Technology” are Registered Trademarks of

Monolithic Power Systems, Inc.

TYPICAL APPLICATION

R1

Q2

Output

8

MP6903

PGND

EN

LL

NC

7

6

5

4

3

2

1

GND

VG1

VG1

Output

U1

VG2

EN

VG2

8

MP6903

PGND

EN

LL

NC

7

6

5

4

3

2

1

U2

C1

C2

R2

R3

C3

C4

R4

Or Left

Open

2.2uF

100k

1nF

100k

1nF

120k

10k

R5

R6

1k

1k

Q1

Qa

Qb