1 Introduction

The LM2734 demo board is configured to convert 5-V input to 1.8-V output at 1-A load current using the LM2734X 1.6-MHz or the LM2734Y 550-kHz step down DC-DC regulator. The tiny low profile thin SOT23 package allows the demo board to be manufactured using less than 1 square inch of a 4-layer printed circuit board.

The circuit is configured with the boost diode connected to V_IN, and according to the data sheet, V_IN must not exceed the maximum operating limit of 5.5 V + V_fD2 using this configuration. This makes sure that the voltage between the Boost and SW pins, V_BOOST - V_SW, does not exceed 5.5 V for proper operation. Please see the LM2734 data sheet for more information regarding this requirement.

A bill of materials in Table 2-1 and Table 2-2 describes the parts used on this demo board. A schematic and layout have also been included in Figure 2-1 along with measured performance characteristics. The schematics at the end of this document show how to re-configure this demo board for various input and output conditions as discussed in the LM2734 data sheet. Short or leave open the indicated connection as indicated in the schematics. The above restrictions for the input voltage are valid only for the demo board as shipped with the demo board schematic below.