Each linear voltage regulator has its own advantages and disadvantages, and it is ultimately up to the designer to determine whether a certain type of voltage regulator is suitable for equipment use according to the requirements of differential pressure, grounding current and stability compensation method.

    The voltage difference and ground current value are mainly determined by the pass element of the linear regulator, and the type of equipment applicable to the regulator can be determined after the voltage difference and ground current value are set. Each of the five major linear regulators in use today has a different pass element and unique performance, which are suitable for different devices.

    The advantage of a standard NPN regulator is that it has a stable ground current approximately equal to the base current of a PNP transistor and is fairly stable even without an output capacitance. This regulator is more suitable for the use of equipment with high voltage difference, but the high pressure difference makes this regulator not suitable for many embedded devices.

    For embedded applications, the NPN bypass transistor regulator is a good choice because it has a small pressure difference and is very easy to use. However, this regulator is still not suitable for battery powered equipment with very low pressure difference requirements, because its pressure difference is not low enough. Its high-gain NPN bypass tube keeps the ground current stable at a few milliamps, and its common emitter structure has a very low output impedance.

    PNP bypass transistor is a low-voltage differential regulator, in which the bypass component is PNP transistor. Its input and output pressure difference is generally between 0.3 and 0.7V. Because of the low differential pressure, this PNP bypass transistor regulator is ideal for use in battery-powered embedded devices. However, its high ground current will shorten the battery life. In addition, PNP transistors have low gain and can form unstable ground currents of several milliamps. Due to its common emitter structure, its output impedance is relatively high, which means that capacitors with a specific range capacity and equivalent series resistance (ESR) are required to operate stably.

    Due to their low differential pressure and ground current, P-channel FET regulators are now widely used in many battery-powered devices. This type of regulator uses a P-channel FET as its bypass element. The voltage difference of this regulator can be very low because it is easy to adjust the drain-source impedance to a lower value by adjusting the size of the FET. Another useful feature is the low ground current because the "gate current" of the P-channel FETs is low. However, because the P-channel FET has a relatively large gate capacitance, it requires external capacitors with a specific range of capacity and ESR to work stably.

    N-channel FET regulators are ideal for devices that require low voltage differentials, low ground currents, and high load currents. N-channel FETs are used for bypass tubes, so the voltage difference and ground current of this regulator are very low. Although it also requires an external capacitor to work stably, the capacitance value does not need to be large, and the ESR is not important. N-channel FET regulators require a charge pump to establish the grid bias voltage, so the circuit is relatively complex. Fortunately, the N-channel FET is up to 50% smaller than the P-channel FET at the same load current.