DESCRIPTION

The MP1543 is a highly efficient, synchronous, fixed frequency, current-mode step-up converter with output to input disconnect, inrush current limiting and internal soft-start. It includes an error amplifier, ramp generator, comparator, N-Channel switch and P-Channel synchronous rectified switch (which greatly improves efficiency). The output disconnect feature allows the output to be completely isolated from the input in shutdown mode.

The 500KHz switching frequency allows for smaller external components producing a compact solution for a wide range of load currents. The internal compensation and soft-start minimizes the external component count and limits the inrush current during startup. The MP1543 regulates the output voltage up to 6V and provides up to 400mA from a 2-cell AA with a 3.3V output.

FEATURES

• Over 90% Efficiency

• Output to Input Disconnect at Shutdown Mode

• Internal Synchronous Rectifier

• Inrush Current Limiting and Internal Soft-Start

• Internal Compensation

• 1.5A Typical Switch Current Limit

• 500KHz Fixed Switching Frequency

• Zero Current Shutdown Mode

• Thermal Shutdown

• 5-Pin TSOT-23 Package

APPLICATIONS

• MP3 Players

• Handheld Computers and PDAs

• Digital Still and Video Cameras

• External Modems

• Small LCD Displays