Patent ID: 7965151
Filing Date: 2011-06-21
Classification: H03K

Abstract:
1. A pulse width modulator (PWM), comprising: a driver coupled to output a first and a subsequent period of a PWM signal, wherein the first period includes the PWM signal changing between first and second states, and wherein the subsequent period includes the PWM signal changing between the first and second states; a two-way integrator, including a capacitor, coupled to integrate an input current and to generate a duty ratio signal, wherein the two-way integrator integrates the input current during the first period by charging the capacitor and integrates the input current during the subsequent period by discharging the capacitor, and wherein the driver determines a first duty ratio of the first period and a subsequent duty ratio of the subsequent period by adjusting the PWM signal to the second state in response to the duty ratio signal; and a timer coupled to the driver and coupled to generate a pulse signal, wherein the driver sets a beginning of the first and the subsequent period of the PWM signal by adjusting the PWM signal to the first state in response to the pulse signal.