Anglia Components |
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STMicroelectronics audio power amplifier chip delivers 200W output, targets multi-channel applications
Merging the benefits of class AB and class D, the BASH technology uses DMOS power transistors operated in class AB mode, reducing the EMI and distortion typical of class D switching amplifiers. To maximize efficiency, by continually adjusting the power supply voltage, depending on the amplitude of the amplified audio signal, a constant voltage drop is achieved across the output transistors, completely independent of the output amplitude. Implementing this technique allows the STA5150 to deliver 200W into a four-ohm load with less than 10% distortion, and with an efficiency three times better than a conventional Class AB. "By bringing together Indigo's patented high efficiency amplification technique and ST's best-in-class BCD technology we have once again set the standard for performance in integrated audio amplifiers," said Riccardo Ferrari, General Manager of ST's Audio Division. "This new amplifier chip reconfirms ST's technological leadership, since 1969, in audio power amplification chips." Each STA5150 device includes a 200W audio power amplifier channel. This amplifier is mainly used in multi-channel multimedia audio systems such as the 5.1 channel surround sound commonly used in A/V receivers. Other BASH-equipped audio power amplifiers available include the 2x100 STA575, 2x70W STA550 and STA530, a quad amplifier fully configurable from 4x50W to 2x50W+ 1x100W. The power amplifiers are used in conjunction with a digital processor, the STABP01, which is the controller for a buck (step-down) converter and implements the BASH supply voltage variation technique, by using a reference feedback signal derived from the power amplifier stage. "We are very pleased that Indigo's high efficiency technology has been adopted by STMicroelectronics for the new STA5150 and other integrated power amplifiers," said Joe Riggi, Vice President of Indigo Manufacturing Inc. "This fruitful co-operation between our companies benefits system designers by delivering high power multi-channel audio at a competitive cost. STA5150 power amplifiers are assembled in ST's proprietary Flexiwatt plastic package, developed to provide excellent thermal performance, easy assembly and robustness. The products include comprehensive protection features that guard against overload and anomalous supply conditions. By using a BASH specific external circuit topology, it's possible to provide an intended reduction of the power supply voltage, sensing the power stage and the external buck converter to achieve a further improvement of the overall systems' protection scheme. For more information on the full range of STMicroelectronics products available from Anglia please call +44 (0)1945 474747 or email info@anglia.com |
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This news article was published in October 2004.
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18/10/04