MP4655

Pure, Single-Stage, LLC, LED Current

and System Voltage Controller

MP4655 Rev 1.0

www.MonolithicPower.com

1

2/2/2016

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

© 2016 MPS. All Rights Reserved.

The Future of Analog IC Technology

DESCRIPTION

The MP4655 is a pure, single-stage, LLC, LED

current and system voltage controller for LED

backlighting, especially in larger TVs, and is

located on the secondary side. The MP4655

uses an LLC power stage and an extra N-

channel MOSFET to regulate both the LED

current and the system supply voltage. The

MP4655 is powered by input supplies ranging

from 9V to 35V that output two 180 degree

phase shifted driving signals for the external

LLC power stages. Its enhanced 12V gate

driver provides sufficient driving capability and

can drive the external LLC MOSFETs directly

through an external gate-driving transformer.

The MP4655 also provides a direct driving

signal to control the extra N-channel MOSFET

and regulate the system supply voltage.

The MP4655 incorporates both PWM dimming

and analog dimming for the LED current. A

driving signal is output to directly drive the

dimming MOSFET, which helps achieve fast

and high-contrast ratio PWM dimming. The

analog dimming can be achieved through a DC

signal on ADIM or a pulse signal on ADIMP.

The

MP4655

employs

smart

protection

methods to protect the LED driver stage and

system power stage in the event that a fault

occurs, increasing system reliability.

Full protection features for the LED include

open LED protection, short LED protection,

over-LED current protection, feedback open

loop protection, and protection for any point of

the LED string shorting to ground.

Full protection features for the system supply

voltage stage include over-voltage protection

(OVP), over-current protection (OCP), and

feedback open-loop protection. The MP4655

uses an extra individual capacitive mode

protection to protect the LLC power stage in

any condition system in the event it enters

capacitive mode. The MP4655 also employs

thermal shutdown and is available in a SOIC-28

package.

FEATURES

• Pure, 1-Stage LLC for LED Current and

System Supply Voltage Regulation

• CC/CV Frequency Control Loop and Duty

Cycle Control Loop

• Audible Noise Elimination

• 9V to 35V Input Voltage Range

• Deep and Fast PWM Dimming

• Analog Dimming with DC or Pulse Input

Signal

• Input Under-Voltage Lockout (UVLO)

• System Supply Over-Voltage Protection

(OVP)

• System Supply Short Protection

• LED Open, LED Short Protection

• LED String Short to GND Protection

• Open Feedback Loop Protection for System

Bus Voltage and LED Driver

• Capacitive Mode Protection for LLC

• Soft Switching for the Extra N-Channel

MOSFET

• Fault Indicator

• Available in a SOIC-28 Package

APPLICATIONS

• LCD TVs and Monitors

• Desktop LCD Flat Panel Displays

• Flat Panel Video Displays

• Street Lighting

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

MPS green status, please visit the MPS website under Quality

Assurance. “MPS” and “The Future of Analog IC Technology” are registered

trademarks of Monolithic Power Systems, Inc.