Copyright © 2016, Texas Instruments Incorporated

RT/SD

FB

VIN

SW

RTN

BST

6V - 95V

Input

LM5008A

SHUTDOWN

RCL

VCC

VIN

GND

RCL

RT

C1

C3

C4

L1

D1

RFB2

RFB1

R3

C2

GND

VOUT

Product

Folder

Order

Now

Technical

Documents

Tools &

Software

Support &

Community

An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,

intellectual property matters and other important disclaimers. PRODUCTION DATA.

LM5008A

SNVS583H – MARCH 2009 – REVISED OCTOBER 2018

LM5008A 95-V, 350-mA, Constant On-Time DC/DC Buck Switching Regulator

1

1 Features

1

•

Operating Input Voltage Range: 6 V to 95 V

•

Integrated 100-V N-Channel Buck Switch

•

Internal Start-Up Regulator

•

No Loop Compensation Required

•

Ultra-Fast Transient Response

•

On-Time Varies Inversely With Input Voltage

•

Operating Frequency Remains Constant With

Varying Line Voltage and Load Current

•

Adjustable Output Voltage From 2.5 V

•

Highly Efficient Operation

•

Precision Internal Reference

•

Low Bias Current

•

Intelligent Current Limit

•

Thermal Shutdown

•

8-Pin VSSOP and 8-Pin WSON Packages

•

Create a Custom Design Using the LM5008A With

the WEBENCH® Power Designer

2 Applications

•

Non-Isolated Telecommunication Buck Regulators

•

Secondary High-Voltage Post Regulators

•

48-V Automotive Systems

3 Description

The LM5008A DC/DC converter is a functional variant

of the LM5008 COT Buck Switching Regulator. The

functional differences of the LM5008A are: the

minimum input operating voltage is 6 V, the on-time

equation is slightly different, and the requirement for

a minimum load current is removed.

The LM5008A 350-mA step-down switching regulator

features all of the functions required to implement a

low-cost and efficient buck regulator. This high-

voltage converter has an integrated 100-V N-channel

buck switch and operates over an input voltage range

of 6 V to 95 V. The device is easy to implement and

is provided in 8-pin VSSOP and the thermally

enhanced 8-pin WSON packages. The converter

uses PWM control scheme with an on-time inversely

proportional to VIN. This feature allows the operating

frequency to remain relatively constant. The control

scheme requires no loop compensation. An intelligent

current limit is implemented with forced off-time,

which is inversely proportional to VOUT. This scheme

ensures short-circuit control while providing minimum

foldback. Other features include: thermal shutdown,

VCC undervoltage lockout, gate drive undervoltage

lockout, maximum duty cycle limiter, and a pre-

charge switch.

Device Information(1)

PART NUMBER

PACKAGE

BODY SIZE (NOM)

LM5008A

VSSOP (8)

3.00 mm × 3.00 mm

WSON (8)

4.00 mm × 4.00 mm

(1) For all available packages, see the orderable addendum at

the end of the data sheet.

Typical Application, Basic Step-Down Regulator