RT4841

4

DS4841-00 May 2021

www.richtek.com

©

Copyright

2021 Richtek Technology Corporation. All rights reserved.

is a registered trademark of Richtek Technology Corporation.

Functional Block Diagram

Control

and

Driver

Logic

Current

Sense

Slope

Compen-

Sation

Oscillator

Summing

Comparator

Clock

Error

Amplifier

1.25V

SW

GND

EN

COMP

FB

Protection

OVP

OTP

SWO

VIN

Soft-Start

SS

VL

BOOT

SWI

BT

VL

Regulator

OCP

Ext-GD MOS

Control

SWG

+

-

+

-

Operation

The RT4841 is a 5A Synchronous Boost Converter with

Output Isolation MOS. It is a synchronous current mode

boost converter integrated with a 22V/5A isolation power

switch, covering a wide VIN range from 8.6V to 15.9V. It

performs high efficiency and fast transient responses to

generate source driver supplies for TFT LCD display. The

synchronous step-up converter uses a current mode, pulse

width modulation (PWM) topology with a built in N-

MOSFET to achieve high efficiency and fast transient

response in TFT-LCD applications. The output voltage can

be adjusted by setting the resistive voltage-divider sensing

at the FB pin. The error amplifier varies the COMP voltage

by sensing the FB pin to regulate the output voltage. For

better stability, the slope compensation signal summed

with the current sense signal will be compared with the

COMP voltage to determine the current trip point and duty

cycle.