All-Digital Audio Power Amplifier Chips from STMicroelectronics Reduce Cost, Size of DVD Home Theater Systems and Component Stereos.Business & Technology Editors GENEVA--(BUSINESS WIRE)--April 3, 2002 Based on DDX DDx abbreviation for differential diagnosis; used in medical records. (R) technology, ST's new digital audio chip family delivers up to 100W per channel using small-outline plastic packages. STMicroelectronics (NYSE NYSE See: New York Stock Exchange :STM (Scanning Tunneling Microscope) A microscope that can image down to the atomic level. An STM uses a piezoelectric tube with a tiny sharp tip at the end that is moved within nanometers of the object being sampled. ) introduced today a family of Direct Digital Amplification (DDX) digital audio amplifier chips that improve sound quality while reducing power consumption, size and cost. Aimed primarily at applications in DVD DVD: see digital versatile disc. DVD in full digital video disc or digital versatile disc Type of optical disc. The DVD represents the second generation of compact-disc (CD) technology. home theater systems and mini component stereos, these chips allow powerful surround sound systems to be housed in a compact enclosure. Direct Digital Amplification (DDX) was developed by Apogee Technology Inc. (Nasdaq:APGT) and licensed exclusively to STMicroelectronics for dedicated integrated circuits. Designed by Apogee for submicron CMOS (Complementary Metal Oxide Semiconductor) Pronounced "c-moss." The most widely used integrated circuit design. It is found in almost every electronic product from handheld devices to mainframes. technology, the DDX IP complements perfectly ST's bipolar-CMOS-DMOS (BCD (Binary Coded Decimal) The storage of numbers in which each decimal digit is converted into binary and is stored in a single character or byte. For example, a 12-digit number would take 12 bytes. See binary numbers. ) technology - a mixed process that allows submicron CMOS to be combined with power DMOS DMOS Double-Diffused Metal-Oxide Semiconductor DMOS Diffusion Metal Oxide Semiconductor DMOS Duty Military Occupational Specialty DMOS Diffusive Mixing of Organic Solutions DMOS Distributed Mature Object Space DMOS Discrete Metal Oxide Semiconductor on the same chip. The combination of BCD power technology and innovative surface mounting packages allows ST to deliver DDX solutions with leading edge performance in large volumes at an affordable cost. Direct Digital Amplification improves audio performance by eliminating the need for digital-to-analog converters. In addition, by replacing conventional class AB audio amplifiers with more efficient switching amplifiers the power wasted as heat in the amplifier is greatly reduced, which both cuts power consumption and the need for expensive heatsinks to cool the chips. Unlike conventional class D switching power amplifiers, DDX uses a patented damped ternary (programming) ternary - A description of an operator taking three arguments. The only common example is C's ?: operator which is used in the form "CONDITION ? EXP1 : EXP2" and returns EXP1 if CONDITION is true else EXP2. pulse-width modulation scheme that further improves efficiency. A typical DDX amplifier will be 20% more efficient than a comparable class D amplifier An audio amplifier that works in the digital domain. It generates the equivalent analog output for the speakers by using pulse width modulation (PWM) or pulse density modulation (PDM) rather than the traditional digital-to-analog conversion. See PWM and PDM. and 300% more efficient that a class AB design. ST's implementation of the DDX technology partitions the functions between control processor and power amplifiers. The control processor chips perform the basic DDX modulation function plus other DSP-based signal functions for surround sound features, tone and volume controls. Parts commercially available today include the STA304A controller plus two power amplifier types: the STA500 and STA505. The STA304A converts two serial digital inputs in IIS (Internet Information Services) Microsoft's Web server. IIS runs under the server versions of Windows, adding HTTP server capability to the Windows operating system. or S/PDIF (Sony/Philips Digital InterFace) A serial interface for transferring digital audio from CD and DVD players to amplifiers and TVs. S/PDIF is typically used to transmit PCM and Dolby Digital 5.1, but is not tied to any sampling rate or audio standard. format into five channels of digital drive for DDX power amplifiers. Additionally it performs surround sound processing plus volume, tone and balance controls. Other functions such as equalization can be added by embedding additional software. The STA500 and STA505 power amplifiers differ only in the power rating. Type STA500 delivers 2x30W or 60W in parallel mode; the STA505 delivers 2x50W or 100W in parallel mode. Both chips include protection features against low or high supply voltages and provide a thermal warning output used by the STA304A to avoid a shutdown by reducing power to a safe level. Thanks to the very high efficiency of the DDX approach the STA500 is assembled in a PowerSO36 package, a power package developed by ST that combines the benefits of surface mounting with high power capability. Externally it is similar in design to the standard small-outline plastic package but internally a copper leadframe enhances thermal performance and a metal flag conducts heat to the printed circuit board. The STA505 is assembled in a similar package with the die mounting flag on the upper side so an external heatsink may be added. Using the ST DDX amplifier chips a typical 5+1 x 30W channel surround sound system for a DVD Home Theater can be built using two STA304A controllers and three or four STA500 power amplifiers, along with ST's DVD solutions such the L6315 optical interface and STi5519 or STi5580 DVD MPEG decoders. Thanks to the small size, low power consumption and cool operation this application can be built inside a standard DVD player unit, reducing the size and cost of high-performance home theater systems to mass market levels. Design and development costs are also reduced because there are no low-level analog signals, so board design is simplified and digital noise problems are avoided. DDX audio amplifier technology can also be used to build powerful and compact digital mini component stereos, all digital active PC loudspeakers, pure digital audio players, compact disk players, minidisc players and completely digital receivers for digital radio services. Future products now in development will target these applications. About STMicroelectronics STMicroelectronics, the world's third largest independent semiconductor company, is a global leader in developing and delivering semiconductor solutions across the spectrum of microelectronics applications. An unrivalled combination of silicon and system expertise, manufacturing strength, Intellectual Property (IP) portfolio and strategic partners positions the Company at the forefront of System-on-Chip (SoC) technology and its products play a key role in enabling today's convergence markets. The Company's shares are traded on the New York Stock Exchange New York Stock Exchange (NYSE) World's largest marketplace for securities. The exchange began as an informal meeting of 24 men in 1792 on what is now Wall Street in New York City. , on Euronext Paris and on the Milan Stock Exchange Milan Stock Exchange The largest regional stock exchange in Italy, facilitating more than 90% of the country's trading volume. . In 2001, the Company's net revenues were $6.36 billion and net earnings were $257.1 million. Further information on ST can be found at www.st.com. Trademarks: (R) DDX is a registered trademark of Apogee Technology Inc. |
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