Linear converters reduce output voltage with a resistive load. In a typical circuit of this type, the input and output are connected with a transistor (RVT1 in the picture below). The input voltage is reduced by the voltage across the transistor, which causes the output voltage to drop.
Such circuits are quite simple and cheap but have a number of serious drawbacks. They can only be used to decrease voltage. Moreover, their efficiency drops as the difference between the input and output voltage rises. As long as the device isn’t powered by batteries, this drop is irrelevant. On the other hand, this unused power dissipates as heat, and such models overheat easily if the input and output voltages differ greatly.
Nevertheless, they are used in low-power devices and nodes that require high-quality output voltage and low output voltage ripple, or in devices that are sensitive to electromagnetic interference. They are simple in design, use few components, and can save a lot of space (unless there’s a need to use a heat sink). Linear converters dc dc are typically used in audio and video electronics, communication equipment, medical and measurement devices.
Switching converters use a switching element that charges a storage capacitor with electrical pulses. This voltage is then smoothed with the capacitor and transferred to the load. The output voltage level is defined by the duty cycle of the switching element.
