RT/SD

FB

VIN

SW

RTN

BST

6V - 95V

Input

SM74301

SHUTDOWN

RCL

VCC

GND

C1

C3

C4

L1

D1

R3

C2

GND

SM74301

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SNVS719A – JULY 2011

SM74301 100V, 350 mA Constant On-Time Buck Switching Regulator

Check for Samples: SM74301

1

FEATURES

PACKAGE

2

•

Renewable Energy Grade

•

VSSOP-8

•

Operating Input Voltage Range: 6V to 95V

•

WSON-8 (4mm x 4mm)

•

Integrated 100V, N-Channel Buck Switch

DESCRIPTION

•

Internal Start-Up Regulator

The SM74301 is a Constant On-Time (COT) Buck

•

No Loop Compensation Required

Switching

Regulator

which

operates

at

a

low

•

Ultra-Fast Transient Response

minimum input voltage of 6V and does not require a

minimum load current as some other COT parts.

•

On Time Varies Inversely with Input Voltage

•

Operating Frequency Remains Constant with

The

SM74301

Step

Down

Switching

Regulator

Varying Line Voltage and Load Current

features all of the functions needed to implement a

low cost, efficient, Buck bias regulator. This high

•

Adjustable Output Voltage from 2.5V

voltage regulator contains a 100V N-Channel Buck

•

Highly Efficient Operation

Switch. The device is easy to implement and is

•

Precision Internal Reference

provided in the VSSOP-8 and the thermally enhanced

WSON-8 packages. The regulator is based on a

•

Low Bias Current

control

scheme

using

an

ON

time

inversely

•

Intelligent Current Limit

•

Thermal Shutdown

frequency to remain relatively constant. The control

scheme requires no loop compensation. An intelligent

current limit is implemented with forced OFF time,

TYPICAL APPLICATIONS

which is inversely proportional to Vout. This scheme

•

High Voltage Photovoltaic Systems

ensures short circuit control while providing minimum

•

Non-Isolated Telecommunication Buck

foldback. Other features include: Thermal Shutdown,

Regulator

lockout, Max Duty Cycle limiter, and a pre-charge

•

Secondary High Voltage Post Regulator

switch.

Typical Application, Basic Step-Down Regulator

1

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of

Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

2

All trademarks are the property of their respective owners.

PRODUCTION DATA information is current as of publication date.

Copyright © 2011, Texas Instruments Incorporated

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.