Digital system and method for generating analog control signals
AssigneeApplied Materials, Inc.
InventorJames B. Atkisson, Jr.
Life of this patent
Estimating the term…
Abstract
Digital system and method for generating analog control signals wherein a plurality of straight line segments are fitted to the desired wave form, and signals representative of the changes in amplitude and time for each segment are stored in a digital memory. The amplitude and time signals are processed to provide digital signals corresponding to a plurality of points disposed generally along the line segments, and these digital signals are converted to analog form to provide an output signal which increases and/or decreases in a plurality of incremental steps at a rate corresponding to the slopes of the line segments.
Claims14
In a method utilizing digital storage means, signal processing circuitry and a digital-to-analog converter for generating an analog control signal having an amplitude which varies with time according to a predetermined waveform, the steps of:
- storing a plurality of amplitude signals representative of the changes in amplitude between predetermined points in the analog waveform, storing a plurality of time signals representative of the time intervals between the predetermined points, providing pulses at rates corresponding to successive ones of the stored amplitude signals, counting the pulses and providing an output pulse each time the count reaches a number corresponding to one of the stored time signals, converting the output pules to an analog output signal which advances in stepwise fashion along line segments interconnecting the predetermined points, storing a jump signal indicative of the occurrence of an instantaneous change in the amplitude of the analog signal and converting one of the stored amplitude signals directly to analog form to provide the output signal in response to the jump signal.
In a system for generating an analog control signal having an amplitude which varies with time according to a predetermined waveform:
- digital memory means for storing amplitude and time signals respectively representative of changes in amplitude and time between predetermined points in the analog waveform, means for providing pulses at rates corresponding to successive ones of the stored amplitude signals, counter means responsive to the pulses for delivering an output pulse each time the count reaches a level corresponding to one of the stored signals, digital-to-analog converter means responsive to the output pulses for delivering an analog output signal which advances in a stepwise fashion along line segments interconnecting the predetermined points, means for storing a jump signal indicative of the occurrence of an instantaneous change in the amplitude of the analog signal, means for applying the amplitude signals to preset inputs of the counter means, and means for conditioning the counter to transfer the amplitude signals from the preset inputs directly to the output lines of the counter means in response to the jump signal.
In a system for generating an analog control signal having an amplitude which varies with time according to a predetermined waveform:
- digital memory means for storing amplitude and time signals respectively representative of changes in amplitude and time between predetermined points in the analog waveform, a source of pulses occurring at a predetermined rate, rate multiplier means responsive to the pulses and to the amplitude signals for delivering pulses at rates corresponding to the product of the predetermined rate and numbers represented by the amplitude signals, means for dividing the pulses from the multiplier means by numbers corresponding to the time signals to provide output pulses defining stepped line segments interconnecting the predetermined points of the output waveform, digital counting means responsive to the output pulses, digital-to-analog converter means connected to the outputs of the counting means for delivering an analog output signal corresponding to the stepped line segments, means for storing jump signals indicative of the occurrence of instantaneous changes in the amplitude of the analog waveform, means for applying the amplitude signals to preset inputs of the counting means, and means responsive to the jump signals for conditioning the counting means to transfer the amplitude signals directly from the preset inputs to the outputs of the counting means.
Dependencies are inferred from the claim text.