Method and circuit for converting an analog signal into a simultaneous digital signal

Claim 2

Circuit for converting the amplitude of an analog current signal in a given interval of time into a substantially simultaneous digital signal which comprises: means for generating a stepped current electrical scale having a plurality of n steps for evaluating said analog current amplitude comprising circuit means having at least n-1 pairs of diodes, each said pair having the two diodes thereof connected in parallel with opposed polarity, and means for applying a respective calibrated constant current to said diode pairs at respective terminals thereof for generating therewith said stepped current electrical scale; means for applying said analog current amplitude to said circuit means having said diode pairs for measuring said amplitude by causing said circuit means to have a related voltage distribution where the location of the highest value is indicative of said analog current amplitude; and means for obtaining in a given interval of time during said measurement a digital signal which indicates said highest voltage value corresponding to the step of said current electrical scale which is exceeded by said analog amplitude in said given interval of time.

Claim 3

Circuit as set forth in claim 1 including means for providing a digital representation of said measured analog amplitude from said digital signal having an encoder therein.

Claim 4

Circuit as set forth in claim 2 wherein said encoder includes a diode matrix.

Claim 5

Circuit as set forth in claim 1 wherein said means for providing said digital representation includes at least one electronic switch for each said step of said scale which is responsive to the potential at a terminal of a related diode pair for selecting the highest step of said electrical scale which is exceeded by said analog amplitude.

Claim 6

Circuit as set forth in claim 1 wherein said diode pairs are connected in series in a path which is grounded at one end and a plurality of constant current sources are each connected to one of the nodes respectively between the diode pairs which are not grounded and to the node at the other end of the path for supplying said respective calibrated current to each of said nodes, and conductor means is connected to said node at the other end of the path for drawing said current amplitude.

Claim 7

Circuit as set forth in claim 4 wherein said electronic switches are transistors which have respective bases, emitters and collectors, and each base of said transistors is connected to a resPective node of a diode pair, and the emitters of said transistors are connected in common to another constant current source which draws a given current which is carried by the one of said transistors which has the highest potential at its base.

Claim 8

Circuit as set forth in claim 6 wherein each said switching transistor is associated with a respective feedback network which is related to a respective calibrated current source which is connected to the same node of said row of diode pairs so that said given current which flows through said respective switching transistor increases the calibrated current supplied by said respective calibrated current source by an increment.

Claim 9

Circuit as set forth in claim 1 wherein each said diode pair has one terminal thereof grounded and has the other terminal thereof connected to a respective line which supplies a respective calibrated current and said other terminal is further connected to a respective line from which said analog current amplitude is drawn.

Claim 10

Circuit as set forth in claim 2 wherein said means for providing said digital representation includes at least one electronic switch for each said step of said scale which is responsive to the potential at a terminal of a related diode pair for selecting the highest step of said electrical scale which is exceeded by said analog amplitude.

Claim 11

Circuit as set forth in claim 9 wherein each said electronic switch includes two transistors of which one transistor is connected to one terminal of a respective diode pair and the other transistor is connected to the other terminal of said respective diode pair, both of said transistors which are related to one diode pair are connected to a common constant current source for supplying a given current, and one transistor of said pair of transistors and the neighboring transistor of the adjacent pair of transistors are connected to a respective common line for leading back the given current carried by one of said transistors which are connected to said common line.

Claim 12

Circuit as set forth in claim 10 including an encoder for providing a digital representation of said analog amplitude, wherein said common line is connected to said encoder.

Claim 13

Method for converting the amplitude of an analog current signal in a given interval of time into a substantially simultaneous digital signal comprising the steps of: generating a stepped current electrical scale having a plurality of n steps for evaluating said analog current amplitude, measuring said amplitude by causing said electrical scale to have a related voltage distribution with a highest value which is indicative of said analog current amplitude including comparing said analog current with at least one calibrated current of a plurality of calibrated currents which define said steps of said current electrical scale, reversing the polarity of a respective voltage which is related to a respective step of said current electrical scale whenever said analog current increases above said step, and restoring the original polarity of said respective voltage when said analog current decreases below said highest step of said electrical scale; and generating in a given interval of time during measurement a digital signal which indicates said highest voltage value corresponding to said current electrical scale which is exceeded by said analog amplitude in said given interval of time.

Claim 14

Method for converting the amplitude of an analog current signal in a given interval of time into a substantially simultaneous digital signal comprising the steps of: generating a stepped current electrical scale having a plurality of n steps for evaluating said analog current amplitude, measuring said amplitude by causing said electrical scale to have a related voltage distribution with a highest value which is indicative of said analog current amplitude including comparing said analog current with at least one calibrated current of a plurality of calibrated currents which define said steps of said current electrical scale, reversing the polarity of a respective voltage which is related to a respective step of said current electrical scale whenever said analog current increases above said step, and restoring the original polarity of said respective voltage when said analog current decreases below said highest step of said electrical scale; and generating in a given interval of time during measurement a digital signal which indicates said highest voltage value corresponding to said current electrical scale which is exceeded by said analog amplitude in said given interval of time.

Claim 15

Method according to claim 12 including the step of generating an analog current proportional to an analog amplitude, comparing said analog current with at least one calibrated current of a plurality of calibrated currents which define said steps of said electrical scale, reversing the polarity of a respective voltage which is related to a respective step of said electrical scale whenever said analog current increases above said step, and restoring the original polarity of said respective voltage when said analog current decreases below said steP of said electrical scale.

Claim 16

Method according to claim 13 including the step of evaluating said reversal of polarity of said respective voltage for generating said digital signal which indicates the highest step of said electrical scale which is exceeded by said analog current.

Claim 17

Method according to claim 13 including the step of increasing by an increment the calibrated current which is supplied to the next higher step in said scale whenever said digital signal is generated.