Abstract: The inventive A/D and D/A conversion device replaces the conventional parameter generators, which are provided in pairs for supplying same filter parameters to the decimation and interpolation digital filters respectively, with a single parameter generator, thereby having the number of parameter generators and reducing the scale of circuit.

Abstract: An integrating D-A/A-D converter includes a reference value generation circuit for generating at least one reference value relating to voltage or current, a control circuit for carrying out switching between a digital or analog input and the reference value every predetermined time to connect a switched one to thereby control an integral time, and an integration circuit for respectively integrating an analog value corresponding to the digital or analog input and the reference value switched in sequence every predetermined time and delivered through the control circuit to output an integral value for providing a digital or analog output.

Abstract: A converter circuit provides analog to digital and digital to analog functions on a single silicon device. A flash analog to digital converter produces digital outputs using comparators which each receive an input signal and which each have different reference voltages. A decoder receiving digital inputs activates switches to connect selected ones of the same voltage references used by the flash analog to digital converter to a buffer which produces an analog output. The converter circuit can be a single or multi-stage flash analog to digital converter operating in a single channel or multi-channel environment. Timing and control logic prevents switching from occurring at times when perturbations on the voltage references could affect the analog and digital outputs.

Abstract: An A/D-D/A converting apparatus, in which a multiplier is omitted by storing the multiplied result of a filter coefficient and a digital signal in advance and reading it out responsive to the inputted digital signal, in view of the point that filter characteristics of digital filters of an A/D converting unit and a D/A converting unit are equal one another, memories which are coefficient generating devices are used in common, and further, in view of the point :hat processing contents of respective digital filters are equal, a multiplier and an accumulator constituting the digital filter are used in common to reduce a circuit configuration considerably.

Abstract: A codec comprises a control circuit for generating a frame synchronous signal and a clock signal which are controlled to comply with different types of data carried on a received digital signal to be converted to a received analog signal in a decoder and data carried on a transmitting digital signal converted from a transmitting analog signal.

Abstract: An apparatus adaptable for use in effecting communications between an analog device and a digital device, having an analog-digital-analog circuit for converting incoming analog signals received from the analog device to incoming digital signals, and for converting interpolated outgoing digital signals to outgoing analog signals. The analog-digital-analog device includes a single digital-to-analog converter and switches for selectively configuring the analog-digital-analog circuit to effect conversion of incoming analog signals to incoming digital signals or, alternatively, to effect conversion of outgoing digital signals to outgoing analog signals.

Abstract: A conversion system is disclosed for performing either an analog-to-digital A/D conversion associated with an amplification step or a digital-to-analog D/A conversion associated with an attenuation step. The system includes apparatus (115) for receiving a input digital word to be processed, i.e. converted into analog and then attenuated, and apparatus (165) for receiving a input analog value to be processed, i.e. amplified for scaling purposes and then converted into digital. It also includes a digital-to-analog D/A converter (110), an attenuator (120) for attenuating the analog output of D/A converter (110), and a comparator (150) for comparing the value of the input analog value to be processed and the output of said attenuator (120). The processing of the D/A-attenuation process is performed by both the D/A converter (110) and attenuator (120).

Abstract: An analog-to-digital and digital-to-analog converter includes an array of capacitors each being differently weighed from the others, one electrode of each of the capacitors being connected to a common node. Switches are provided for selectively applying, in response to a first control signal, an analog input applied to an analog input terminal and a plurality of reference voltages to the other electrode of the capacitors. A comparator has a pair of input terminals whose inverting and non-inverting inputs are selectively switched over with respect to polarity in response to a second control signal. The comparator compares a voltage appearing on the node and applied to one of the input terminals and one of the reference voltages applied to the other input terminal. An analog output terminal is connected to the output of the comparator. A successive comparison register sequentially takes in outputs of the comparator in response to a third control signal.