IRAUDAMP9 Datasheet, PDF (15/39 Pages) International Rectifier – 1.7 kW / 2-Ω Single Channel Class D Audio Power Amplifier Using the IRS2092S and IRFB4227

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IRAUDAMP9 w/ 2-Pair of IRFB4227 @ +/-75Vdc 2-ohm R_load
Total System Efficiency
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Total Output Power (W)
Fig.12 Efficiency plots.
Output Filter and Preamplifier
Output filter:
The amplified PWM output is reconstructed back to an analog signal by the output LC LPF.
This LPF is formed by L4 and C34, provides pass band for the audio frequencies while filtering out
the switching carrier signal. A single stage output filter can be used with switching frequencies of
around 300 kHz ; a design with a lower switching frequency may require an additional stage of
filtering.
Since the output filter is not included in the control loop of the IRAUDAMP9, the reference design
cannot compensate for performance deterioration due to the output filter. Therefore, it is important
to select filter components with the following characteristics in mind.
1) The DC resistance of the inductor should be minimized to 6 mΩ or less.
2) The linearity of the output inductor and capacitor should be high with respect to load
current and voltage.
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IRAUDAMP9 REV 1.0
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