RT8059

®

DS8059-04 December 2011

www.richtek.com

Copyright 2011 Richtek Technology Corporation. All rights reserved.

is a registered trademark of Richtek Technology Corporation.

©

1

Features

Wide Input Voltage from 2.8V to 5.5V

1A Output Current

95% Efficiency

No Schottky Diode Required

1.5MHz Fixed Frequency PWM Operation

Small TSOT-23-5 Package

RoHS Compliant and Halogen Free

Applications

NIC Card

Cellular Telephones

Personal Information Appliances

Wireless and DSL Modems

MP3 Players

Portable Instruments

1.5MHz, 1A, High Efficiency PWM Step-Down DC/DC Converter

General Description

The RT8059 is a high efficiency Pulse Width Modulated

(PWM) step-down DC/DC converter, capable of delivering

1A output current over a wide input voltage range from

2.8V to 5.5V. The RT8059 is ideally suited for portable

electronic devices that are powered by 1-cell Li-ion battery

or by other power sources within the range, such as cellular

phones, PDAs and handy-terminals.

reduces conduction loss at PWM mode. No external

Schottky diode is required in practical applications. The

RT8059 automatically turns off the synchronous rectifier

when the inductor current is low and enters discontinuous

PWM mode. This can increase efficiency in light load

condition.

The RT8059 enters low dropout mode when normal PWM

cannot provide regulated output voltage by continuously

turning on the upper P-MOSFET. The RT8059 enters

shutdown mode and consumes less than 0.1

μA when the

EN pin is pulled low.

The switching ripple can be easily smoothed out by small

package filtering elements due to a fixed operation

frequency of 1.5MHz. This along with small TSOT-23-5

package provides small PCB area application. Other

features include soft-start, lower internal reference voltage

with 2% accuracy, over temperature protection, and over

current protection.

Ordering Information

Pin Configurations

(TOP VIEW)

TSOT-23-5

Note :

Richtek products are :

RoHS compliant and compatible with the current

require-

ments of IPC/JEDEC J-STD-020.

Suitable for use in SnPb or Pb-free soldering

processes.

EN GND LX

FB

VIN

4

23

5

BQ= : Product Code

DNN : Date Code

Marking Information

BQ=DNN

RT8059

Package Type

J5 : TSOT-23-5

Lead Plating System

G : Green (Halogen Free and Pb Free)