LM5010A

High Voltage 1A Step Down Switching Regulator

General Description

The LM5010A Step Down Switching Regulator is an en-

hanced version of the LM5010 with the input operating range

extended to 6V minimum. The LM5010A features all the

functions needed to implement a low cost, efficient, buck

regulator capable of supplying in excess of 1A load current.

This high voltage regulator integrates an N-Channel Buck

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

TSSOP-14EP packages. The constant on-time regulation

scheme requires no loop compensation resulting in fast load

transient response and simplified 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: VCC under-voltage

lock-out, thermal shutdown, gate drive under-voltage lock-

out, and maximum duty cycle limiter.

Features

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Wide 6V to 75V Input Voltage Range

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Valley Current Limiting At 1.25A

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Programmable Switching Frequency Up To 1 MHz

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Integrated 80V N-Channel Buck Switch

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Integrated High Voltage Bias Regulator

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No Loop Compensation Required

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Ultra-Fast Transient Response

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Nearly Constant Operating Frequency With Line and

Load Variations

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Adjustable Output Voltage

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Programmable Soft-Start

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Thermal shutdown

Typical Applications

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Non-Isolated Telecommunications Regulator

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Secondary Side Post Regulator

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Power SUpply for Automotive Electronics

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

Basic Step Down Regulator

20153843

October 2005

© 2005 National Semiconductor Corporation

DS201538

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