US Patent 9065401 Amplification systems and methods with noise reductions

System and method for amplifying an input signal to generate an output signal. The system includes a current generator, an oscillator, and a comparator. The current generator is configured to receive a first voltage signal, and generate a first current signal based on at least information associated with the first voltage signal and the first reference signal. The oscillator is configured to receive at least the first current signal and a second reference signal, and to generate a second voltage signal based on at least information associated with the first current signal and the second reference signal, the second voltage signal being associated with a modulation frequency. Additionally, the comparator is configured to receive the second voltage signal and a third voltage signal, and to generate a modulation signal related to the modulation frequency based on at least information associated with the second voltage signal and the third voltage signal.