One-sided pulse width modulated (PWM) amplifiers are disclosed. An example amplifier includes an integrator to receive first and second analog signals, and to output a first amplified signal and a second amplified signal based on the first and second analog signals, a reference changer coupled to the integrator to determine whether a first amplitude is higher than a second amplitude based on the first and second analog signals, to selectively cause the integrator to apply a first resistance between a reference node and the first amplified signal and apply a second resistance between the reference node and the second amplified signal when the first amplitude is higher than the second amplitude, and to selectively cause the integrator to apply the second resistance between the reference node and the first amplified signal and apply the first resistance between the reference node and the second amplified signal when the second amplitude is higher than the first amplitude, and first and second comparators coupled to the integrator to receive the first and second amplified signals, to compare the first and second amplified signals to a reference signal, and to output first and second pulse width modulated signals having respective first and second pulse widths based on the comparisons between the first and second amplified signals and the reference signal.