Analog-to-digital converter

Claim 2

An analog-to-digital converter stage including a stage input terminal: a stage input terminal; a stage output terminal for producing a residual signal for application to a succeeding stage; means establishing a threshold voltage; circuit means connected to said stage input terminal and responsive to an analog signal applied thereto for providing a circuit means output signal having a magnitude proportional to the difference in magnitude between said analog signal and said threshold voltage and having a first polarity in the event said analog signal magnitude exceeds said threshold voltage and a second polarity in the event said analog signal magnitude is less than said threshold voltage; a differential amplifier having first and second input terminals and an output terminal; oppositely directed unidirectional current analog means respectively coupling said circuit means output signal to said first and second differential amplifier input terminals; and means connecting said differential amplifier output terminal to said stage output terminal.

Claim 3

The stage of claim 1 including relatively low impedance means connecting said differential amplifier first input terminal to a source of reference potential; and feedback path means connecting said differential amplifier output terminal to said differential amplifier second input terminal.

Claim 4

An analog to reflected binary code converter comprising: a converter input terminal; a converter output terminal; a plurality of substantially identical stages including first and last stages and one or more intermediate stages, each of said stages having an input terminal and an output terminal; each of said stages including a differential amplifier means responsive to a signal applied thereto whose level lies within a predetermined range for providing a residual signal at the stage output terminal whose level is proportional to the absolute difference between the level of said applied signal and the midpoint of said range; means connecting said converter input terminal to said first stage input terminal; means connecting each of said first and intermediate stage output terminals to the input terminal of succeeding stage; means cOnnecting said last stage output terminal to said converter output terminal; each of said differential amplifier means comprising a differential amplifier having first and second input terminals and an output terminal; and means including oppositely directed unidirectional current conducting devices respectively connecting each stage input terminal to the first and second input terminals of the differential amplifier of that stage.

Claim 5

An analog to reflected binary code converter comprising: a converter input terminal; a converter output terminal; a plurality of substantially identical stages including first and last stages and one or more intermediate stages, each of said stages having an input terminal and an output terminal; each of said stages including a differential amplifier means responsive to a signal applied thereto whose level lies within a predetermined range for providing a residual signal at the stage output terminal whose level is proportional to the absolute difference between the level of said applied signal and the midpoint of said range; means connecting said converter input terminal to said first stage input terminal; means connecting each of said first and intermediate stage output terminals to the input terminal of succeeding stage; means cOnnecting said last stage output terminal to said converter output terminal; each of said differential amplifier means comprising a differential amplifier having first and second input terminals and an output terminal; and means including oppositely directed unidirectional current conducting devices respectively connecting each stage input terminal to the first and second input terminals of the differential amplifier of that stage.

Claim 6

The converter of claim 3 including relatively low impedance means connecting said differential amplifier first input terminal to a source of reference potential; and feedback path means connecting said differential amplifier output terminal to said differential amplifier second input terminal.

Claim 7

An analog to reflected binary code converter comprising: a converter input terminal; a converter output terminal; a plurality of substantially identical stages including first and last stages and one or more intermediate stages, each of said stages having an input terminal and an output terminal; each of said stages including a differential amplifier means responsive to a signal applied thereto whose level lies within a predetermined range for providing a residual signal at the stage output terminal whose level is proportional to the absolute difference between the level of said applied signal and the midpoint of said range; means connecting said converter input terminal to said first stage input terminal; means connecting each of said first and intermediate stage output terminals to the input terminal of a succeeding stage; means connecting said last stage output terminal to said converter output terminal; each of said stages including amplifier means connecting the stage input terminal to the differential amplifier means thereof, each of said amplifier means having input and output terminals; and first and second oppositely directed unidirectional current conducting means connecting the output terminal of each of said amplifier means to the input terminal thereof.

Claim 8

An analog to reflected binary code converter comprising: a converter input terminal; a converter output terminal; a plurality of substantially identical stages including first and last stages and one or more intermediate stages, each of said stages having an input terminal and an output terminal; each of said stages including a differential amplifier means responsive to a signal applied thereto whose level lies within a predetermined range for providing a residual signal at the stage output terminal whose level is proportional to the absolute difference between the level of said applied signal and the midpoint of said range; means connecting said converter input terminal to said first stage input terminal; means connecting each of said first and intermediate stage output terminals to the input terminal of a succeeding stage; means connecting said last stage output terminal to said converter output terminal; each of said stages including amplifier means connecting the stage input terminal to the differential amplifier means thereof, each of said amplifier means having input and output terminals; and first and second oppositely directed unidirectional current conducting means connecting the output terminal of each of said amplifier means to the input terminal thereof.

Claim 9

The converter of claim 5 wherein each of said stages includes a normalizing means connecting said stage input terminal to said amplifier means input terminal, said normalizing means including trimming means for adjusting the range of signal applied to said amplifier means input terminal to be symmetric with respect to some predetermined signal level.

Claim 10

The converter of claim 5 wherein each of said differential amplifier means comprises a differential amplifier having first and second input terminals and an output terminal; and third and fourth oppositely directed unidirectional current conducting means respectively connecting the amplifier means output terminal of each stage to the first and second input terminals of the differential amplifier stage.

Claim 11

The converter of claim 7 including relatively low impedance means connecting said differential amplifier first input terminal to a source of reference potential; and feedback path means connecting said differential amplifier output terminal to said differential amplifier second input terminal.

Claim 12

A converter stage for converting an analog signal within a predetermined range to reflected binary code signals, said converter stage including: a stage input terminal; a stage output terminal for producing a residual signal for application to a succeeding stage; circuit means connected between said stage input terminal and said stage output terminal for inverting signals applied to said stage input terminal having a level extending in a first direction from the midpoint of said predetermined range and for directly coupling without inversion signals applied to said stage input terminal having a level extending in a second direction from said midpoint; said circuit means including a differential amplifier having first and second amplifier input terminals and an amplifier output terminal; and coupling means connecting said stage Input terminal to said first and second amplifier input terminals and said amplifier output terminal to said stage output terminal.

Claim 13

A converter stage for converting an analog signal within a predetermined range to reflected binary code signals, said converter stage including: a stage input terminal; a stage output terminal for producing a residual signal for application to a succeeding stage; circuit means connected between said stage input terminal and said stage output terminal for inverting signals applied to said stage input terminal having a level extending in a first direction from the midpoint of said predetermined range and for directly coupling without inversion signals applied to said stage input terminal having a level extending in a second direction from said midpoint; said circuit means including a differential amplifier having first and second amplifier input terminals and an amplifier output terminal; and coupling means connecting said stage Input terminal to said first and second amplifier input terminals and said amplifier output terminal to said stage output terminal.

Claim 14

The converter stage of claim 9 wherein said coupling means includes first and second oppositely directed unidirectional current conducting means respectively connecting said stage input terminal to said first and second amplifier input terminals.