Patent application number | Description | Published |
20080246511 | Differential Drive Circuit and Electronic Apparatus Incorporating the Same - A differential driving circuit used for low voltage differential signals and an electronic device incorporating the same are provided wherein no differential amplifiers are used or the number of differential amplifiers are reduced, thereby reducing the circuit area and the current consumption and further solving the problem of oscillation caused by noise, while a high driving performance is achieved. There are included a switch circuit an output circuit and a reference potential generating circuit. The switch circuit, which comprises MOS transistors, receives differential signals and outputs current signals. The output circuit comprises an NMOS transistor, an end of which is connected to the power supply potential of a higher potential side, the other end of which is connected to a node of the switch circuit and which acts as a source follower, and an PMOS transistor, an end of which is connected to the power supply potential of a lower potential side, the other end of which is connected to the other node of the switch circuit and which acts as a source follower. The reference potential generating circuit supplies reference potentials to the respective gates of the PMOS and NMOS transistors. The reference potential generating circuit includes a potential varying means that varies the differential potentials with an offset potential kept constant. Further, there is included an emphasis circuit for the output circuit. | 10-09-2008 |
20100239101 | Digital speaker driving apparatus - A digital sound system suitable for a digital speaker device for directly converting analog sound by a circuit using a ΔΣ modulator and a mismatch shaping filter circuit to output a plurality of digital signals and a plurality of speakers driven by the plurality of digital signals. A digital speaker driving device includes a ΔΣ modulator, a post filter, s driving circuits, and a power supply circuit to supply power to the ΔΣ modulator, the post filter and the s driving elements and the s driving circuits are adapted to s digital signal terminals. | 09-23-2010 |
20130058497 | DIGITAL SPEAKER DRIVING APPARATUS - A digital sound system suitable for a digital speaker device to directly convert analog sound by a circuit using a ΔΣ modulator and a mismatch shaping filter circuit to output a plurality of digital signals and a plurality of speakers driven by the plurality of digital signals. A digital speaker driving device includes a ΔΣ modulator, a post filter, s driving circuits, and a power supply circuit to supply power to the ΔΣ modulator, the post filter and the s driving elements, and the s driving circuits are adapted to s digital signal terminals. | 03-07-2013 |
20140169577 | DRIVE CIRCUIT - As one embodiment of the present invention, provided is a drive circuit to which a three-value signal including a value representing zero is input, and that outputs two two-value signals that drive two drive elements such that the difference between values representing the two two-value signals corresponds to a value representing the input three-value signal, the drive circuit being characterized by the combination of the output two two-value signals when the value of the input three-value signal represents zero being determined in accordance with the input history of the three-value signal. The drive circuit may also be provided with a memory that records a flag value that is reversed in accordance with the input history of the input three-value signal, and the combination of the output two two-value signals being determined in accordance with the flag. | 06-19-2014 |
20140236332 | DIGITAL ACOUSTIC SYSTEM - Provided is a digital acoustic system comprising: a ΔΣ modulator that modulates a digital input signal and outputs a digital signal; a post-filter that is connected to the ΔΣ modulator and which performs mismatch shaping to convert the digital signal; a parallel-serial converter that converts the digital signal converted by the post-filter into a digital signal which is serially transmitted; a serial-parallel converter that restores the digital signal converted by the parallel-serial converter; and a drive circuit which receives the digital signal restored by the serial-parallel converter, and drives drive elements to convert the signal into an analog audio signal. | 08-21-2014 |
20150236713 | CONVERTER - Provided is a data converter which is provided with a clock signal input part which inputs a clock signal, and an input part which inputs an input signal, a sampling part which, in response to the clock signal input to the clock signal input part, performs sampling of the input signal input to the input part, and a signal processing part which performs signal processing according to the sampling cycle and outputs an output signal, wherein when the cycle of the clock signal input to the clock signal input part becomes longer, the output signals output by the signal processing part are reduced. | 08-20-2015 |
20150310024 | ACOUSTIC PLAYBACK SYSTEM - An acoustic playback system including a digital filter; and a plurality of digital modulators each of which output a digital signal to one of a plurality of speakers driven by digital signals having different play back bandwidths; wherein the digital filter converts a digital audio signal which is input into a plurality of digital audio signals of a plurality of frequency bandwidths corresponding to play back bandwidths of the speakers, and outputs each of the digital audio signals of the plurality of frequency bandwidths to one of the plurality of digital modulators; each of the digital modulators outputs the modulated digital signal to the speaker of a play back bandwidth corresponding to a frequency bandwidth of the digital audio signal which is input by performing miss-match shaping after noise shaping to a digital audio signal; and each number of bits of a digital signal of the digital modulators is different. | 10-29-2015 |
20160044402 | DIGITAL SPEAKER DRIVING APPARATUS - A digital sound system suitable for a digital speaker device to directly convert analog sound by a circuit using a ΔΣ modulator and a mismatch shaping filter circuit to output a plurality of digital signals and a plurality of speakers driven by the plurality of digital signals. A digital speaker driving device includes a ΔΣ modulator, a post filter, s driving circuits, and a power supply circuit to supply power to the ΔΣ modulator, the post filter and the s driving elements, and the s driving circuits are adapted to s digital signal terminals. | 02-11-2016 |