7.2 Feature Description

The LM3103 Step Down Switching Regulator features all required functions to implement a cost effective, efficient buck power converter which is capable of supplying 0.75 A to loads. It contains dual N-Channel main and synchronous MOSFETs. The Constant ON-Time (COT) regulation scheme requires no loop compensation, results in a fast load transient response and simple circuit implementation. The regulator can function properly even with an all ceramic output capacitor network, and does not rely on the output capacitor’s ESR for stability. The operating frequency remains constant with line variations due to the inverse relationship between the input voltage and the on-time. The valley current limit detection circuit, with a limit set internally at 0.9 A, inhibits the main MOSFET until the inductor current level subsides.

The LM3103 can be applied in numerous applications and can operate efficiently for inputs as high as 42 V. Protection features include V_CC under-voltage lockout, output over-voltage protection, thermal shutdown, gate drive under-voltage lock-out. The LM3103 is available in the thermally enhanced HTSSOP-16 package.