DELTA-CODEC Russian patent published in 2001 - IPC

FIELD: electrical communications; digital telephone sets. SUBSTANCE: delta-codec that has analog integrators of first and second digital-to-analog converters of delta-coder and delta-decoder, respectively, as well as input low-frequency filter and fifth-order output filter built around change-over capacitors whose capacitance is passed from phase-locked loop at frequency of 128 kHz which is synchronized in phase at frequency of 32 or 64 kHz of input sync signal is provided, in addition, with input digital signal level shifting device. Delta-codec circuit is built around single chip which provides for its miniaturization and makes it possible to vary data transmission rate in codec and to extend codec speed variation range . EFFECT: improved conversion of fast-varying analog signals into digital form. 4 cl, 1 dwg