LM5007

High Voltage (80V) Step Down Switching Regulator

General Description

The LM5007 Step Down Switching Regulator features all of

the functions needed to implement low cost, efficient, Buck

bias regulators. This high voltage regulator contains an 80 V,

0.7A N-Channel Buck Switch. The device is easy to apply

and is provided in the MSOP-8 and the thermally enhanced

LLP-8 packages. The regulator is based on a hysteretic

control scheme using an on time inversely proportional to

V

relatively constant with load and input voltage variations. The

hysteretic control requires no control loop compensation,

while providing very fast load transient response. An intelli-

gent current limit is implemented in the LM5007 with forced

off time that is inversely proportional to V

limiting scheme reduces load current foldback. Additional

protection features include: Thermal Shutdown, Vcc under-

voltage lockout, gate drive undervoltage lockout, and Max

Duty Cycle limiter.

Features

n

Integrated 80V, 0.7A N-Channel Buck Switch

n

Internal HV Vcc Regulator

n

No Control Loop Compensation Required

n

Ultra-Fast Transient Response

n

On Time Varies Inversely with Line Voltage

n

Operating Frequency Nearly Constant with Varying Line

Voltage

n

Adjustable Output Voltage

n

Highly Efficient Operation

n

Precision Reference

n

Low Bias Current

n

Intelligent Current Limit Protection

n

Thermal Shutdown

n

External Shutdown Control

Typical Applications

n

Non-Isolated Buck Regulator

n

Secondary High Voltage Post Regulator

n

+42V Automotive Systems

Package

n

MSOP - 8

n

LLP - 8 (4mm x 4mm)

Connection Diagram

20078302

8-Lead MSOP, LLP

Ordering Information

Order Number

Package Type

NSC Package Drawing

Supplied As

LM5007MM

MSOP-8

MUA08A

1000 Units on Tape and Reel

LM5007MMX

MSOP-8

MUA08A

3500 Units on Tape and Reel

LM5007SD

LLP-8

SDC08A

Available Soon

LM5007SDX

LLP-8

SDC08A

Available Soon

January 2004

© 2004 National Semiconductor Corporation

DS200783

www.national.com