Systems and methods for compressing a digital signal in a digital microphone system

A system comprising:

• a microphone transducer configured to generate an analog input signal indicative of audio sounds incident upon the microphone transducer;
• and
• a digital processing system configured to convert the analog input signal into a digital signal having a plurality of quantization levels, such that each quantization level is uniquely obtained by a determined transition or of one or more bits of the digital signal during a sampling period of the digital signals;
• wherein:
• the digital signal has three quantization levels, including:
• a first quantization level that corresponds to an increase in the analog input signal;
• a second quantization level that corresponds to no change of the analog input signal;
• and
• a third quantization level that corresponds to a decrease in the analog input signal;
• the quantization level of the digital signal is represented by a transition or lack of transition of the digital signal;
• and
• the digital processing system is further configured to:
• communicate the digital signal on a bus interleaved with one or more control signals;
• and
• suppress communication of control signals when the digital signal is of the second quantization level.

A method comprising:

• generating an analog input signal indicative of audio sounds incident upon a microphone transducer;
• converting the analog input signal into a first digital signal having a plurality of quantization levels;
• and
• in the digital domain, processing the first digital signal to compress the first digital signal into a second digital signal having fewer quantization levels than that of the first digital signal, such that a third digital signal equivalent to the first digital signal can be reconstructed from the second digital signal;
• wherein:
• each quantization level of the second digital signal is represented by one of a plurality of possible digital codes;
• the number of possible digital codes is more than the number of quantization levels of the second digital signal;
• and
• one or more of the possible digital codes not corresponding to quantization levels represent a control signal associated with the digital microphone system.

A method comprising:

• generating an analog input signal indicative of audio sounds incident upon a microphone transducer;
• converting the analog input signal into a digital signal having a plurality of quantization levels, such that each quantization level is uniquely obtained by a determined transition or of one or more bits of the digital signal during a sampling period of the digital signal, wherein:
• the digital signal has three quantization levels, including:
• a first quantization level that corresponds to an increase in the analog input signal;
• a second quantization level that corresponds to no change of the analog input signal;
• and
• a third quantization level that corresponds to a decrease in the analog input signal;
• and
• the quantization level of the digital signal is represented by a transition or lack of transition of the digital signal;
• communicating the digital signal on a bus interleaved with one or more control signals;
• and
• suppressing communication of control signals when the digital signal is of the second quantization level.

An integrated circuit comprising:

• a microphone input configured to receive an analog input signal indicative of audio sounds incident upon a microphone transducer;
• and
• a processing circuit configured to:
• convert the analog input signal into a first digital signal having a plurality of quantization levels;
• and
• in the digital domain, process the first digital signal to compress the first digital signal into a second digital signal having fewer quantization levels than that of the first digital signal, such that a third digital signal equivalent to the first digital signal can be reconstructed from the second digital signal;
• wherein:
• each quantization level of the second digital signal is represented by one of a plurality of possible digital codes;
• the number of possible digital codes is more than the number of quantization levels of the second digital signal;
• and
• one or more of the possible digital codes not corresponding to quantization levels represent a control signal associated with the digital microphone system.

An integrated circuit comprising:

• a microphone input configured to receive an analog input signal indicative of audio sounds incident upon a microphone transducer;
• and
• a processing circuit configured to convert the analog input signal into a digital signal having a plurality of quantization levels, such that each quantization level is uniquely obtained by a determined transition or of one or more bits of the digital signal during a sampling period of the digital signal;
• wherein:
• the digital signal has three quantization levels, including:
• a first quantization level that corresponds to an increase in the analog input signal;
• a second quantization level that corresponds to no change of the analog input signal;
• and
• a third quantization level that corresponds to a decrease in the analog input signal;
• the quantization level of the digital signal is represented by a transition or lack of transition of the digital signal;
• and
• the processing circuit is further configured to:
• communicate the digital signal on a bus interleaved with one or more control signals;
• and
• suppress communication of control signals when the digital signal is of the second quantization level.