Current controlled pulse width modulation circuit and class-D amplifier comprising the same

摘要

A pulse width modulation (PWM) circuit comprising an input circuit, first and second controllers, and first and second Schmidt triggers. The first controller sets a first voltage level by a first current generated responding to an input signal and an output of the input circuit. The first Schmidt trigger sets a first logic level when an output of the first controller reaches the first voltage level. The second controller sets a second voltage level by a second current generated responding to the input signal and an output of the first Schmidt trigger. The second Schmidt trigger generates a PWM output signal with a variable frequency in accordance with the first and second currents.