Abstract: Various embodiments of the invention relate to a battery charging system that enhances the charge rate and reduces the charge time for a battery applied in a mobile device. The battery charging system is provided with an adapter output voltage, and generates a battery charging current to drive the battery. This adapter output voltage is controlled to vary within a reference voltage range which is narrowly controlled to include and track a preferred adapter voltage. The battery is therefore driven by the battery charging current that is associated with a preferred charging current under a preferred charging condition. The battery charging process may be completed under a condition that is substantially close to the preferred charging condition, allowing an enhanced battery charge rate and a reduced battery charge time.

Abstract: A low drop out linear voltage regulator (200) overcomes the dynamic quiescent current limitation by creating an internal zero that moves in the same direction and has the same amplitude as that of the output pole without sensing a portion of the load current. The low drop out linear voltage regulator (200) having frequency compensation in accordance with the present invention includes an error amplifier (202), a NMOS pass transistor (204), a variable compensation network (Ci, 206), and a stabilization circuit (208, 210, I3, I4). The error amplifier (202) includes a power supply input connected to a first power supply, a non-inverting input coupled to a reference voltage, a inverting input and an output terminal. The NMOS pass transistor (204) includes a source connected to an output terminal of the voltage regulator, a drain coupled to the second power supply, and a gate coupled to the output terminal of the error amplifier. The variable compensation network (Ci, 206) connects to the error amplifier.