PULSE WIDTH MODULATION CIRCUIT AND CLASS-D AMPLIFIER COMPRISING THE PWM CIRCUIT

摘要

A pulse width modulation (PWM) circuit comprises a first integrator (g m1) with a first feedback capacitor (C1), a second integrator (gm1) with a second feedback capacitor (C2) and a comparator (A0) having a first input (V1) connected to the output of the first integrator (gm1) and a second input (V2) connected to the output of the second integrator (gm2). A connection path comprising a resistor (R2) is established from the output of the first integrator (gm1) to an input of the second integrator (gm2). The first and second feedback capacitors (C1, C2) have capacities with a non-linear factor X(V) and a circuit with an inversely non-linear factor X−1(V) is arranged in the connection path between the output of the first integrator (gm1) and said input of the second integrator (gm2). The PWM circuit may form path of a Class-D amplifier.