NJU25008

The NJU25008 is a 24-bit digital signal processor dedicated to decoding a stereo audio source and creating the sensation of being surrounded by multiple speakers.Based on patented technology of NJU25008 from SRS Labs, TruSurround TM utilizes head related transfer functions (HRTFs) to envelop the listener with full 3600 surround coming from only a pair of speakers.One of the distinguishing advantages of TruSurround is a broad "sweet spot," offering effective virtual surround within an area up io 75% between the speakers and some surround effect outside the area between the speakers.

Features of the NJU25008 are:(1)SRS trusurround 3D surround processing; (2)dolby pro logic decoder with optional subwoofer output; (3)dolby 3 stereo with optional subwoofer output; (4)subwoofer filter; (5)front high pass filters; (6)default or programmable cutoff frequencies; (7)mono-to-stereo synthesis; (8)a ready-to-use DSP-Based 3D audio solution includes on-chip memory.Audio functions are also included in the NJU25008: digital filters for electronic speaker crossovers and digital tone control with separate bass and treble settings.Applications that can benefit from the NJU25008 include Ns,self-powered multimedia speakers, and AN stereo systems used for home theater.

The absolute maximum ratings of the NJU25008 can be summarized as:(1)supply voltage Vdd:-0.3 to 7V;(2)storage temperature:-55 to +125;(3)operating temperature:-20 to 70 ;(4)input,output pin voltage:-0.3 to Vdd+0.3V.Surround information from the audio source is extracted by the dolby pro logic decoder processing in the NJU25008.Head Related Transfer Functions (HRTFs), based on the natural characteristics of the human hearing system, are used on both front and rear surround channels to synthesize virtual surround speakers to the side and rear of the listener.The front HRTFs have frequency tailoring of the difference signals (L-R) to extend the sound image past the physical boundaries of the actual speakers.A different set of frequency coefficients are applied to the Rear HRTFs that have a much greater peak and valley differences and center frequencies.