Bose companion 5 theory of operation

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2 Companion 5 (Rising Star) Theory of Operation Overview Companion 5 is a multi-channel multimedia speaker system connecting to personal computers via a USB 2.0 interface. No sound card is required to enjoy 5.1-channel audio content from the host PC. The two speaker arrays combined with advanced audio processing algorithms provide a spacious presentation of stereo content and a compelling experience with multi-channel content. A control module brings the master volume control, simple touch mute control and jacks for an auxiliary analog stereo input and headphones. The Companion 5 system consisting of the following major components: 1. Bass speaker enclosure with Woofer, DSP board, I/O board and system power supply. 2. Control Module with an 8-foot (2.4M) cable. 3. Two two-element speaker arrays with integrated cables, uniquely keyed and identified for left and right locations. The Bass speaker enclosure is a ported MDF enclosure including the 5.25-inch dual voice-coil transducer and line power transformer. Both are installed inside the acoustic volume in such a manner that they are not serviceable. An electronics enclosure is provided at the back of the MDF enclosure. The heat sink assembly that includes the DSP/Power Amplifier/Power Supply Printed Circuit Assembly, aluminum heat sink, thermal compound, thermal interface material, and clamping bracket are screwed directly to the back wall of the acoustic enclosure. Internal cables connect the DSP/PA/PS assembly to the transformer secondary and the I/O Printed Circuit Assembly that is mounted to the plastic rear cover of the speaker. The control module is not serviceable. Only the interface requirements to the Bass module electron- ics will be discussed in this document. The speaker arrays are mounted on removable speaker stands that are engineered to position the speakers at the correct height and angle on either side of a computer monitor. The transducers contained in the speaker enclosures may be replaced from the front of the enclosure by removing the metal grill. The grill should not be re-used once removed due to deformation during the removal process. The integrated cable is not removable. The balance of this document will concentrate on the electronic assemblies present in the bass module. English Fran ç a is Espa ñol Right (R) speaker Left (L) speaker Control pod Computer USB Acoustimass rear panel 3 2 1 1 4

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3 Power Supplies 3.3V Reg Reg Bose Brand FET Quasi-Regulator VRAW VSNUB 1.2V RegU50, U51 U902, Q9031Q10 U11 10V RegU20 5V Power Supply Block Diagram Bass module rectifies un-regulated power VSNUB from the secondary of the line power transformer. VSNUB is, in turn, converted to the various other potentials required by the system. Nominally 26VDC, this voltage varies with load and line levels, but is limited to 31.5V maximum(assuming line voltage of 140V AC). This voltage is present whenever the bass module is plugged into the wall. All the voltage level source are listed in following table: Node Name Output Voltage nominal Type Input from Outputs to Vsnub +26 Full wave rectifier transformer secondary Vraw Vraw +14 (no load) pre- regulator output VSNUB Power Amplifiers, +5V, VRAW SEN. +10V +10 linear VSNUB Headphone power amplifiers, control module green LED. +5V +5 linear Vraw CODEC Analog power supply +3.3V +3.3 switching VSNUB DSP I/O power supply, digital supply for USB controller, CODEC, EEROM. +1.2V +1.2 switching VSNUB DSP core power supply. SENSOR +3.0 series switch +3.3 Switch able supply for control module touch sensor, control module red LED