Patent ID: 7570109
Filing Date: 2009-08-04
Classification: H03D

Abstract:
1. A system for demodulating amplitude modulated signals, said system comprising: a first comparator configured to convert an amplitude modulated input signal from a waveform to a pulse form using upper and lower threshold signals; a charge pump circuit electrically connected to said first comparator, said charge pump circuit being configured to charge and discharge current in response to said input signal in said pulse form to produce an integrated signal in a triangular pulse form, said charge pump circuit including an inverter switch connected to said first comparator to receive said input signal in said pulse form and a capacitor connected to said inverter switch to charge and discharge said current to produce said integrated signal; and a second comparator electrically connected to said charge pump circuit to receive said integrated signal, said second comparator being configured to convert said integrated signal from said triangular pulse form to a rectangular pulse form using a reference signal to produce a demodulated output signal, wherein said charge pump circuit comprises first and second current sources and said inverter switch connected in series between a first voltage terminal and a second voltage terminal.