LM5010

High Voltage 1A Step Down Switching Regulator

General Description

The LM5010 Step Down Switching Regulator features all the

functions needed to implement a low cost, efficient, buck

bias regulator capable of supplying in excess of 1A load

current. This high voltage regulator contains an N-Channel

Buck Switch, and is available in thermally enhanced LLP-10

and TSSOP-14EP packages. The hysteretic regulation

scheme requires no loop compensation, results in fast load

transient response, and simplifies circuit implementation.

The operating frequency remains constant with line and load

variations due to the inverse relationship between the input

voltage and the on-time. The valley current limit detection is

set at 1.25A. Additional features include: V

lockout, thermal shutdown, gate drive under-voltage lockout,

and maximum duty cycle limiter.

Features

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Input Voltage Range: 8V to 75V

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Valley Current Limit At 1.25A

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Switching Frequency Can Exceed 1 MHz

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Integrated N-Channel Buck Switch

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Integrated Startup Regulator

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No Loop Compensation Required

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Ultra-Fast Transient Response

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Operating Frequency Remains Constant With Load and

Line Variations

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Maximum Duty Cycle Limited During Startup

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Adjustable Output Voltage

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Precision 2.5V Feedback Reference

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Thermal shutdown

Typical Applications

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High Efficiency Point-Of-Load (POL) Regulator

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Non-Isolated Telecommunications Buck Regulator

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Secondary High Voltage Post Regulator

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Automotive Systems

Package

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LLP-10 (4 mmx4mm)

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TSSOP-14EP

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Both Packages Have Exposed Thermal Pad For

Improved Heat Dissipation

20119943

Basic Stepdown Regulator

October 2004

© 2004 National Semiconductor Corporation

DS201199

www.national.com