Method and apparatus for pulse width modulation

A method for generating a pulse width modulated output signal comprising:

• providing a clock input signal;
• providing a period input signal indicative of a selected period for the pulse width modulated output signal;
• providing a pulse positioning input signal representative of a selected position within the selected output period to be occupied by at least one output signal pulse;
• combining said clock input signal, said period input signal and said pulse positioning input signal;
• providing a pulse width modulated output signal having said selected output period, said pulse width modulated output signal further including at least one pulse portion therein, said pulse portion being positioned in accordance with said pulse positioning input signal;
• dividing said output period into subcycle periods;
• and
• generating a pulse portion for each of said subcycle periods, whereby said pulse width modulated output signal is comprised of a number of said subcycle periods.

A signal generating device for generating an output signal, said signal generating device comprising:

• output signal generating circuitry arranged to receive a clock input signal and a period input signal, said output signal generating circuitry being selectively operable to provide an output signal, said input period signal being representative of a selected period for said output signal, said output signal generating circuitry being selectively operable to generate said output signal having said selected period, said output signal having at least one pulse signal portion thereof and at least one cycle;
• pulse positioning circuitry coupled to said output signal generating circuitry, said pulse positioning circuitry being selectively operable in response to a variable positioning input signal for selectively positioning said pulse signal portion of said output signal within said period of said output signal;
• and
• edge controlling circuitry, said edge controlling circuitry being selectively operable to add at least one transition to at least one edge of pulses within said output signal thereby making transition occurrences in said output signal independent of input signals to the signal generating device, wherein each cycle has a same number of transitions.

A signal generating device for generating an output signal, said signal generating device comprising:

• output signal generating circuitry arranged to receive a clock input signal and a period input signal, said output signal generating circuitry being selectively operable to provide an output signal, said input period signal being representative of a selected period for said output signal, said output signal generating circuitry being selectively operable to generate said output signal having said selected period, said output signal having at least one pulse signal portion thereof, and wherein:
• said output signal generating circuitry further includes a first counter circuit, said first counter circuit being arranged to receive said clock input signal and a first count input signal, said first count input signal being representative of a first count number corresponding to a selected period for said output signal, said first counter circuit being operable to provide an end period signal after counting down from said first count number;
• said signal generating device further including a second counter circuit, said second counter circuit being arranged to receive said clock input signal and a second count input signal, said second count input signal being representative of a second count number corresponding to a selected delay time between a beginning of a period of said output signal and a beginning of at least a first of said pulse signal portions;
• and said signal generating device further including a third counter circuit, said third counter circuit being arranged to receive said clock input signal and a third count input signal, said third count input signal being representative of a third count input number corresponding to a selected pulse width for at least one of said pulse signal portions;
• and
• pulse positioning circuitry coupled to said output signal generating circuitry, said pulse positioning circuitry being selectively operable in response to a variable positioning input signal for selectively positioning said pulse signal portion of said output signal within said period of said output signal.