This article presents a 28-W class-D amplifier for automotive applications. The combination of a high switching frequency and a hybrid multibit $\Delta \Sigma \text{M}$ -PWM scheme results in high linearity over a wide range of output power, as well as low AM-band EMI. As a result, only a small (150-kHz cutoff frequency), and thus low-cost, LC filter is needed to meet the CISPR-25 EMI average limit (150 kHz–30 MHz) with 10-dB margin. At 28-W output power, the proposed amplifier achieves 91% efficiency while driving a 4- $\Omega $ load from a 14.4-V supply. It attains a peak THD+N of 0.00077% (−102.2 dB) for a 1-kHz input signal.

中文翻译：

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使用混合 Δ Σ M-PWM 方案的 28W、-102.2dB THD+N D 类放大器

本文介绍了一款适用于汽车应用的 28W D 类放大器。高开关频率和混合多位的组合 $\Delta \Sigma \text{M}$ -PWM 方案可在很宽的输出功率范围内实现高线性度，以及低 AM 频段 EMI。因此，只有很小的（150 kHz 截止频率），因此成本很低，液晶显示器需要滤波器来满足 CISPR-25 EMI 平均限制 (150 kHz–30 MHz) 和 10-dB 余量。在 28W 输出功率下，建议的放大器实现 91% 的效率，同时驱动 4-W $\欧米茄 $ 来自 14.4V 电源的负载。对于 1 kHz 输入信号，它达到 0.00077% (-102.2 dB) 的峰值 THD+N。