1 Features

? Operating Input Voltage Range: 6 V to 95 V

? Integrated 100-V, N-Channel Buck Switch

? Internal VCC Regulator

? No Loop Compensation Required

? Ultra-Fast Transient Response

? On-Time Varies Inversely With Line Voltage

? Operating Frequency Remains Constant With

Varying Line Voltage and Load Current

? Adjustable Output Voltage

? Highly Efficient Operation

? Precision Internal Reference

? Low Bias Current

? Intelligent Current Limit Protection

? Thermal Shutdown

? 8-Pin VSSOP and WSON Packages

? Create a Custom Design Using the LM5008 With

the WEBENCH? Power Designer

2 Applications

? Non-Isolated Telecommunication Buck Regulators

? Secondary High-Voltage Post Regulators

? 48-V Automotive Systems

3 Description

The LM5008 350-mA step-down switching converter

features all of the functions needed to implement a

low-cost and efficient buck regulator. This highvoltage

converter has an integrated 100-V N-channel

buck switch and operates over an input voltage range

of 9 V to 95 V. The device is easy to implement and

is provided in the 8-pin VSSOP and the thermally

enhanced 8-pin WSON packages. The converter

uses a hysteretic control scheme with a PWM on-time

inversely proportional to VIN. This feature allows the

operating frequency to remain relatively constant. The

hysteretic control requires no loop compensation. An

intelligent current limit is implemented with forced offtime,

which is inversely proportional to VOUT. This

scheme ensures short-circuit protection while

providing minimum foldback. Other protection

features include: thermal shutdown, VCC undervoltage

lockout, gate drive undervoltage lockout, and

maximum duty cycle limiter.