Method and apparatus for adaptively modifying a pulse width of a pulse width modulated output

Abstract

Systems, methods, and apparatus for improving steady state operation of a pulse width modulator during transient and soft start events are described herein. An apparatus can include a phase component configured to adaptively modify a pulse width of a first pulse width modulated (PWM) output signal based on a pulse width of a PWM input signal. Further, the apparatus can include a power stage component configured to source at least one of a voltage or a current to a load based on the first PWM output signal. In one example, the phase component can be configured to linearly extend the pulse width of the first PWM output signal based on the pulse width of the PWM input signal. In another example, the phase component can be configured to adaptively modify the pulse width of the first PWM output signal based on a predetermined maximum pulse width.

Description

Technical field [0001] The various non-limiting specific examples of the system, method and device for adaptively modifying the pulse width of the output of the pulse width modulator are described in this article. [0002] Priority claim [0003] This application claims the priority of U.S. Provisional Patent Application No. 61 / 307,586 filed on February 14, 2010 and entitled "Method and Apparatus for Linearly Extending the Pulse Width of PWM Pulses in High Duty Cycle Applications" , The full text of the case is incorporated herein by reference. Background technique [0004] The phase multiplier is a pulse width modulator that can modulate two-phase pulse trains or power trains based on a single pulse width modulation (PWM) input signal. For example, two PWM signals are generated by a phase multiplier to drive a complementary power stage coupled to the load-for example, a power stage that provides voltage and current to the load via an inductor and capacitor. Therefore, the existin...

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Problems solved by technology

[0006] For example, during a soft start of a PWM - where the output of the PWM controls the power applied to the voltage source - the duty cycle of the output can be gradually increased; however, when the PWM will This soft start involving existing pulse width modulators can lead to undesirable oscillations (or sudden changes) of the output when the on-time of the output is extended by a fixed extended time - undesirable oscillations or sudden changes which disturb the power supply of the voltage source

[0007] In addition, existing PWM techniques that extend the on-time of the output by a fixed extension time during steady-state operation can switch from high to high during a transient event (eg, during a load coupled to the pulse-width modulator's output). Overvoltage and / or current spikes at the output of the pulse width modulator during the event of a current load switching to a low current load (e.g., 100 amps to 10 amps)

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