RT/SD

FB

VIN

SW

RTN

BST

6V - 95V

Input

LM5008A

SHUTDOWN

RCL

VCC

GND

C1

C3

C4

L1

D1

R3

C2

GND

LM5008A

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SNVS583F – MARCH 2009 – REVISED MARCH 2013

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

Check for Samples: LM5008A

1

FEATURES

DESCRIPTION

The LM5008A is a functional variant of the LM5008

2

•

Operating input voltage range: 6V to 95V

COT

Buck

Switching

Regulator.

The

functional

•

Integrated 100V N-Channel buck switch

differences of the LM5008A are: the minimum input

•

Internal start-up regulator

operating voltage is 6 V, the on-time equation is

slightly different, and the requirement for a minimum

•

No loop compensation required

load current is removed.

•

Ultra-fast transient response

The

LM5008A

Step

Down

Switching

Regulator

•

On time varies inversely with input voltage

features all of the functions needed to implement a

•

Operating frequency remains constant with

low cost, efficient, Buck bias regulator. This high

varying line voltage and load current

voltage regulator contains an 100 V N-Channel Buck

•

Adjustable output voltage from 2.5V

Switch. The device is easy to implement and is

provided in the VSSOP-8 and the thermally enhanced

•

Highly efficient operation

WSON-8 packages. The regulator is based on a

•

Precision internal reference

control

scheme

using

an

ON

time

inversely

•

Low bias current

frequency to remain relatively constant. The control

•

Intelligent current limit

scheme requires no loop compensation. An intelligent

•

Thermal shutdown

current limit is implemented with forced OFF time,

•

VSSOP-8 and WSON-8 (4mm x 4mm) packages

which is inversely proportional to Vout. This scheme

ensures short circuit control while providing minimum

APPLICATIONS

foldback. Other features include: Thermal Shutdown,

•

Non-Isolated Telecommunication Buck

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

Regulator

switch.

•

Secondary High Voltage Post Regulator

•

+42V Automotive Systems

Typical Application, Basic Step-Down Regulator

1

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2

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PRODUCTION DATA information is current as of publication date.

Copyright © 2009–2013, 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.