Publisher Summary This chapter focuses on the designs of non-isolated converters. There are many design variables for power supply designs. All of the designs use current mode pulse width modulation (PWM) control because of its inherent advantages in loop stability and current control. One of the problems with current mode control is subharmonic oscillation at duty cycles greater than 50%. Older integrated circuits (ICs) required external means to provide slope compensation to eliminate subharmonic oscillations. The modern ICs such as buck converter, boost converter, inverting controller, buck/boost converter, and charge pump all contain internal slope compensation. The chapter also presents layout considerations. There are two issues that one has to consider. The first is to design the layout of the power supply circuit so it does not interfere with its own operation. The second is to consider how the voltages and potentially huge current densities can interfere with the rest of the system if the power supply is placed too close to sensitive circuits.