The design 3 is designed to operate with input voltages ranging from 1.62V to 3.6V, compatible with output currents up to 10mA. In terms of efficiency, design 3 can reach up to 83% with 3.6V input and 72% at 1.8V input when operating at 50kHz switching frequency. When the switching frequency is increased to 250kHz, efficiencies of up to 77% with 3.6V input and 62% with 1.8V input are attainable.

Figure 1-3 Block Diagram of Design 3

Figure 2-11 illustrates a block diagram of MCU driven design, it uses MSPM0L1306 to generate two-channel of PMW signals to control the half-bridge composed of a P-MOSFET and a N-MOSFET, which in turn drives the primary winding of the transformer on the non-isolated side and the double voltage circuit on the isolated side. The MSPM0 series MCU's versatility allows for accurate and programmable switching frequency up to 500kHz.