Method and apparatus for interconnecting analog and digital sections of A/D and D/A converters
AssigneeAnalog Devices, Inc.
InventorPaschal T. Minogue
Life of this patent
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Abstract
Input and output sections of an analog-to-digital converter are joined by an interface. In the input section, an analog input signal is converted to a multi-bit digital signal before being converted, by a noise-shaping converter such as a sigma-delta modulator, to a lower bit signal. The lower bit signal is carried across the interface before being converted, by a digital filter to recover the original multi-bit signal. The same principle is applied to the input and output sections of a digital-to-analog converter.
Claims42
An analog-to-digital converter comprising:
- a first section having a multi-bit analog to digital converter for receiving an analog input signal and generating an m-bit digital signal, and
- an m-bit to n-bit converter (where m>n) for receiving the m-bit digital signal and for generating an n-bit digital output signal for outputting across an interface, wherein the m-bit to n-bit converter quantizes the m-bit signal to a lower resolution;
- and
- a second section having processing means which is arranged to receive the n-bit digital signal and to process the received signal to generate an output digital signal.
A digital-to-analog converter comprising:
- a first section having an input for receiving an s-bit digital signal from an interface and for generating a t-bit digital signal, where s<t,
- a digital-to-analog converter which receives the t-bit digital signal and generates an analog output;
- and
- a second section connectable to said first section by said interface and having an input for receiving a digital signal a processor which receives the digital input signal and generates an s-bit digital output signal.
A method of processing an analog signal to generate a digital signal comprising the acts of:
- receiving an analog input signal and generating an m-bit digital signal in a multi-bit analog-to-digital converter;
- converting the m-bit digital signal into an n-bit digital output signal (where m>n) for outputting across an interface, wherein the converting quantizes the m-bit signal to a lower resolution;
- and
- receiving the n-bit digital output signal across said interface and processing the received n-bit digital signal to generate an output digital signal.
A method of processing a digital input signal to generate an analog output signal comprising the acts of:
- in a first section receiving an s-bit digital signal from an interface;
- generating from the s-bit digital signal into a t-bit digital signal (where s<t) at a higher resolution and,
- converting the t-bit digital signal into an analog output signal;
- and
- in a second section, at an input, receiving a digital input signal, and processing the digital input signal to generate said s-bit digital signal and to deliver said s-bit signal to said interface.
Signal processing apparatus for converting a signal between the analog and digital domains comprising an input section and an output section which are connectable to one another by an interface:
- the input section comprising means for converting an input signal into a multi-bit digital format,
- an input converter for quantizing the multi-bit signal so as to generate a lower resolution digital signal which can be sent across the interface;
- an output converter for converting the lower resolution signal into a higher resolution signal;
- and a processor that processes the higher resolution signal to derive an output signal.
Dependencies are inferred from the claim text.