System designers will make trade-offs between cost, design effort and performance when selecting a power module. For systems with one to three power rails, designers may decide to use discrete regulators in order to save cost and meet the time to market schedule. However, as the number of power rails increases and the current rating increases, the design of the power subsystem becomes more challenging and requires significantly more design effort. To meet this challenge, designers may opt to use a power module solution. Designers will also consider the cost of ownership of a discrete design. The cost of ownership is the bill of materials (BOM) cost in addition to the power designer’s time required to design and test the design. Potential re-design changes, manufacturing, and assembly costs are additional expenses for discrete designs. The diagram on this slide shows how a power module can integrate many of the blocks of the discrete design shown earlier. A power module integrates the PWM controller, power MOSFETs, inductor, and compensation network into the package. The designer typically only needs to select the input and output capacitors, and a few resistors to complete a design. The only other consideration in a power subsystem design is the PCB layout.