Fast PFET Buck Controller

LM51031

FEATURES

1.0 A Totem Pole Output Driver

High Speed Oscillator (700 kHz max)

No Stability Compensation Required

Lossless Short Circuit Protection

Vcc Monitor

2.0% Precision Reference

Programmable Soft-Start

Moisture Sensitivity Level 3

The LM51031 is a switching contoller for use in DC-DC converters.

It can be used in the buck topology with a minimum number of

external components. The LM51031 consists of a Vcc monitor for

controlling the state of the device, 1.0A power driver for controlling

the gate of a discrete P-Channel transistor, fixed frequency oscillator,

short circuit protection timer, programmable Soft-Start, precision

ORDERING INFORMATION

reference, fast output voltage monitoring comparator, and output

stage driver logic with latch.

The high frequency oscillator allows the use of small inductiors

and output capacitors, minimizing PC board area and system cost.

The programmable Soft-Start reduces current surges at startup. The

short circuit protection timer signifaicantly reduces the duth cycle to

approximately 1/30 of its cycle during short circuit conditions.

2008 - Ver. 1.0

Device

Marking

Package

LM51031D

LM51031

SOP-8

HTC

DESCRIPTION

−

1 −

SOP-8 PKG

Typical Application (Fixed Output Voltage Versions)

Figure 1. Block Diagram and Typical Application