Data handling system using a sequential approximation encoding and decoding technique

In an encoding and decoding system including, an analog-to-digital encoding means for developing an encoded signal in response to an input signal in which each word has one digit, such encoded signal containing data components determinative of sequential inflection points in said encoded signal, a digital-to-analog decoding means for developing an output signal in response to said encoded signal, and a data linking means for transferring said encoded signal from said encoding means to said decoding means, an improved decoding means comprising:

• decoder logic means including a serial shift register responsive to said encoded signal and having a plurality of binary stages, said logic means providing a first and a second control signal, said first control signal being responsive to the logic state of a selected stage of said register and said second control signal being responsive to the logic state of a pair of selected immediately adjacent stages of said register;
• potential source means responsive to said first control signal and operative to provide a reference potential which is either negative or positive depending on the condition of said first control signal;
• and
• adaptive RC filter means responsive to said reference potential and said second control signal and operative to develop said output signal, said adaptive RC filter means including, capacitor means on which said output signal is developed, a plurality of resistors connected to said capacitor means, and switch means responsive to said second control signal and the condition of said shift register and operative to selectively connect only one of said resistors to said source means whereby said capacitor means is charged to a potential which at any given time is an approximation of said input signal.