7.1 Overview

The LM5007 regulator is an easy-to-use buck DC/DC converter that operates from 9-V to 75-V supply voltage. The device is intended for step-down conversions from 12-V, 24-V, and 48-V unregulated, semi-regulated and fully-regulated supply rails. With integrated 80-V, 0.7-A buck power MOSFET, the LM5007 delivers up to 500-mA DC load current with exceptional efficiency and low input quiescent current in a very small solution size. The device is easy to use and is provided in VSSOP-8 and thermally-enhanced WSON-8 packages. Designed for simple implementation, a nearly fixed-frequency, constant on-time (COT) operation with discontinuous conduction mode (DCM) at light loads is ideal for low-noise, high current, fast transient load requirements. Control loop compensation is not required, reducing design time and external component count. An intelligent current limit scheme is implemented in the LM5007 with forced off-time after current limit detection, which is inversely proportional to V_OUT. This current limiting scheme reduces load current foldback.

The LM5007 incorporates numerous other features for comprehensive system requirements, including VCC undervoltage lockout (UVLO), gate drive UVLO, maximum duty cycle limiter, intelligent current limit off-timer, and thermal shutdown with automatic recovery. These features enable a flexible and easy-to-use platform for a wide range of applications, such as 48-V telecom and the 48-V automotive power bus designs. The pin arrangement is designed for simple and optimized PCB layout, requiring only a few external components.