Common switching power supply topologies include:

1. Single-ended step-down topology (Buck Converter): This is one of the most basic switching power supply topologies. It reduces the input voltage to a lower output voltage through the switching action of a switching transistor. It is suitable for applications requiring an output voltage below the input voltage.

2. Single-ended step-up topology (Boost Converter): This topology raises the input voltage to a higher output voltage through the switching action of a switching transistor. It is suitable for applications requiring an output voltage above the input voltage.

3. Step-up/step-down topology (Buck-Boost Converter): This topology can step the input voltage up or down and offers a wide output voltage range. Controlling the switching action of the switching transistor allows the voltage to be increased or decreased as needed.

4. Flyback topology (Flyback Converter): This is a common isolated switching power supply topology. It uses a transformer to isolate the input from the output and converts voltage by controlling the switching action of the switching transistor. It is suitable for applications requiring input-to-output isolation.

5. Step-down/step-up topology (Cuk Converter): This topology can reduce or increase the input voltage and offers a wide output voltage range. It converts voltage by alternately charging and discharging an inductor.

1. Feedforward forward topology (Forward Converter): Like the flyback topology, it uses a transformer to isolate the input from the output. Unlike the flyback topology, the output current is transferred through the transformer's feedforward winding.

2. Full-bridge topology (Full-Bridge Converter): This uses a bridge configuration with four switching transistors to convert voltage. It can achieve higher power output and provide a higher voltage conversion ratio.

3. Half-bridge topology (Half-Bridge Converter): This is similar to the full-bridge topology but uses only two switching transistors, typically one high-side switch and one low-side switch. It offers higher efficiency and smaller size and is suitable for medium-power applications.

4. Dual-winding forward topology (Push-Pull Converter): This uses two mutually coupled windings to convert voltage through periodic switching. It can provide higher power conversion capability.

5. Series resonant topology (Series Resonant Converter): This uses the characteristics of a resonant circuit to convert voltage. It operates at high frequencies and offers higher efficiency and smaller size.

These are some common switching power supply topologies. Each has its own operating principle, characteristics, and applications. Selecting a suitable topology requires consideration of the input and output voltage ranges, power requirements, efficiency requirements, and other design constraints.