Method of and apparatus for converting a plural-bit digital signal to a pulse width modulated signal

A method of converting an x-bit digital signal to an equivalent pulse width modulated signal having an effective pulse width during a predetermined time period that corresponds to the numerical value of said x-bit digital signal, comprising the steps of dividing said timing period into 2.sup.n sections, wherein n is less than x;

• generating a pulse during each of said 2.sup.n sections having a duration corresponding to the numerical value of said x-bit digital signal divided by 2.sup.n with the assumption that the n lower order bits of said digital signal are each 0;
• detecting the numerical value of said n lower order bits;
• and increasing the duration of the pulses generated in a number of said sections equal to the numerical value of said n lower order bits by an amount corresponding to the lowest numerical value of said digital signal.

Apparatus for generating a pulse width modulated signal corresponding to the value of a plural-bit digital signal, comprising input means for receiving a plural-bit digital signal;

• timing means for generating 2.sup.n timing signals of predetermined duration, the sum of said durations of said 2.sup.n timing signals defining a period during which said pulse width modulated signal is generated;
• pulse width converting means coupled to said input means for converting the plural-bit digital signal less the lower order n bits thereof into a corresponding pulse width signal during each timing signal duration;
• and means for selectively increasing by a predetermined amount the pulse width of said pulse width signals produced during selected ones of said timing signal durations in accordance with the value of said lower order n bits, whereby the sum of all the pulse width modulated signals produced during said 2.sup.n timing signal durations corresponds to the value of said plural-bit digital signal.