DC to DC converters convert a source of direct current (DC) from one voltage level to another. The two most common types of DC to DC converters are linear regulators and switched-mode converters. Linear regulators are inexpensive and much simpler than switch regulators. Linear regulators can provide a very low-noise output voltage, and are very suitable for powering noise-sensitive low-power analog and RF circuits. A popular design approach is to use an LDO, Low Drop-out Regulator, that provides a local "point of load" DC supply to a low power circuit. Linear regulators can output a lower, but not a higher, voltage from the input Electronic switch-mode DC to DC converters convert one DC voltage level to another, by storing the input energy temporarily and then releasing that energy to the output at a different voltage. The storage may be in either magnetic field storage components (inductors, transformers) or electric field storage components (capacitors). This conversion method is more power efficient (often 75% to 98%) than linear voltage regulation (which dissipates unwanted power as heat). This efficiency is beneficial to increasing the running time of battery operated devices.