Digital/analogue conversion apparatus
A digital/analog conversion apparatus for converting a digital signal into an analog signal. The digital/analog conversion apparatus can generate a high-quality analog signal, even when elements configuring the digital/analog conversion apparatus have variance, with high resolution and a small circuit size. The data conversion apparatus is provided with a first data converter for reducing the number of bits of an input signal, a second data converter for converting the format of the first output signal, and a third data converter for conversion into a code which corresponds to the history of the output from the second data converter.
1. A digital speaker system comprising:
a plurality of driver circuits;
a delta sigma modulator to receive a digital audio signal and to generate a first signal;
a mismatch shaper to calculate a selection history of the plurality of driver circuits, to generate a second signal by formatting the first signal which is generated by the delta sigma modulator, and to output a second signal to the plurality of driver circuits which are selected according to the selection history of the plurality of driver circuits;
each of the plurality of driver circuits amplifying the second signal and generating three valued digital signals by using a switching driver; and
a speaker unit having a plurality of voice coils, each of the voice coils directly supplied with a respective one of the three valued digital signals generated by the plurality of driver circuits.
2. The digital speaker system according to claim 1 , wherein the speaker unit adds sound pressure levels which the plurality of voice coils generate.
3. The digital speaker system according to claim 2 , wherein the speaker unit has a single corn driven by the plurality of voice coils.
4. The digital speaker system according to claim 1 , wherein the plurality of voice coils are independently wound.
5. The digital speaker system according to claim 1 , wherein the plurality of voice coils are bunched and wound.
6. The digital speaker system according to claim 1 further comprising a digital delay circuit for delaying the second signal to supply a delayed second signal into said plurality of driver circuit.
7. The digital speaker system according to claim 1 further comprising:
a microphone unit; and
a controller to receive a signal from the microphone and to output a control signal to the delta sigma modulator.
8. The digital speaker system according to claim 7 wherein the microphone unit has a plurality of microphones.
9. The digital speaker system according to claim 8 wherein the microphone unit detects direction of a peripheral noise.
10. The digital speaker system according to claim 1 further comprising:
a transmitter to transmit the second signal; and
a receiver to receive the second signal transmitted from the transmitter and to supply the second signal to said plurality of driver circuits.
11. A digital speaker system comprising a first channel, a second channel, and a plurality of digital speakers each of the plurality of digital speakers having a plurality of voice coils, each of the first channel and the second channel including:
a plurality of driver circuits;
a delta sigma modulator to receive a digital audio signal and to generate a first signal;
a mismatch shaper to calculate a selection history of the plurality of driver circuits, to generate a second signal by formatting the first signal which is generated by the delta sigma modulator, and to output the second signal to the plurality of driver circuits, the plurality of driver circuits selected according to the selection history of the plurality of driver circuits; and
each of the driver circuits amplifying the second signal and generating three valued digital signals by using a switching driver, each of the three valued digital signals directly input to each of the voice coils of each of the plurality of digital speakers;
wherein a first group of the plurality of digital speakers receive digital outputs from the first channel, and a second group of the plurality of digital speakers receive the digital outputs from the second channel.
12. The digital speaker system according to claim 11 further comprising a third channel, wherein the first channel is a left channel, the second channel is a right channel and the third channel is a center channel, and
wherein a third group of the plurality of digital speakers receive the digital outputs with three different levels from the third channel.
13. The digital speaker system according to claim 11 further comprising a third channel, wherein the third group of the plurality of digital speakers selectively receive the digital outputs from the first, second or third channels.
14. The digital speaker system according to claim 12 wherein the speaker unit in the first channel and the speaker unit in the third channel are allocated dynamically and the speaker unit in the second channel and the speaker unit in the third channel are allocated dynamically.