1 Introduction

The LMR12010 is a step down DC-DC regulator that operates at the following switching frequencies: the LMR12010X at 1.6 MHz and the LMR12010Y at 3 MHz. The demo board is configured to convert 5-V input to 1.8-V output at 1-A load current using the Y version. The tiny low profile thin SOT23 package allows the design to use less than 1 square inch of board area.

The circuit is configured with the boost diode connected to V_IN. 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. For more information regarding this requirement, see the LMR12010 SIMPLE SWITCHER® 20Vin, 1A Step-Down Voltage Regulator in SOT-23 Data Sheet.

The schematics at the end of this document show how to reconfigure this demo board for various input and output conditions as discussed in the LMR12010 SIMPLE SWITCHER® 20Vin, 1A Step-Down Voltage Regulator in SOT-23 Data Sheet. Short or leave open the connections as indicated in the schematics. The previously mentioned restrictions for the input voltage are valid only for the demo board as shipped with the demo board schematic shown in Figure 4-3