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Electronic Components Datasheet Search |
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MAX97000 Datasheet(PDF) 20 Page - Maxim Integrated Products |
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MAX97000 Datasheet(HTML) 20 Page - Maxim Integrated Products |
20 / 33 page ![]() Audio Subsystem with Mono Class D Speaker and Class H Headphone Amplifier 20 Figure 4. EMI with 15cm of Speaker Cable Ultra-Low EMI Filterless Output Stage Traditional Class D amplifiers require the use of external LC filters or shielding to meet EN55022B electromag- netic-interference (EMI) regulation standards. Maxim’s patented active emissions limiting edge-rate control circuitry and spread-spectrum modulation reduces EMI emissions, while maintaining up to 87% efficiency. Maxim’s patented spread-spectrum modulation mode flattens wideband spectral components, while propri- etary techniques ensure that the cycle-to-cycle variation of the switching period does not degrade audio repro- duction or efficiency. The MAX97000’s spread-spectrum modulator randomly varies the switching frequency by Q 20kHz around the center frequency (250kHz). Above 10MHz, the wideband spectrum looks like noise for EMI purposes (see Figure 4). FREQUENCY (MHz) 280 260 240 220 200 180 160 140 120 100 80 60 0 10 20 30 40 -10 30 300 FREQUENCY (MHz) 950 900 850 800 750 700 650 600 550 500 450 400 0 10 20 30 40 -10 300 350 1000 |
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