45nm CMOS 8Ω Class-D Audio Driver with 79% Efficiency and 100dB SNR

📋 论文概要

该论文在45nm CMOS工艺中实现了一款Class-D音频驱动器，能够驱动8Ω负载输出525mW功率，并达到了79%的效率和100dB的SNR。为了解决缺少高压晶体管、高器件噪声和漏电等挑战，采用了二阶自然采样BD双面调制（NBDD）环路。

💡 主要创新点

• 在45nm低压CMOS工艺中实现了高效的Class-D音频驱动器，克服了缺少高压器件和器件噪声大的问题。
• 采用二阶自然采样BD双面调制（NBDD）技术，在低电压下实现了高SNR和低失真。
• 实现了紧凑的0.42mm²面积，适合集成到SoC中。

🏷 关键词

📄 原文摘要

Integrating audio and power management into a system-on-chip (SoC) is of interest due to reduced board area and cost. Integrated Class-D audio drivers need to drive high voltages to deliver high power across small loads; 525mW (5.8Vpp differential) across an 8Ω load working off the battery. Absence of highvoltage transistors along with high device noise (flicker), device mismatch and leakage pose design challenges in 45nm CMOS. The 100dB SNR 0.42mm2 Class-D amplifier presented in this paper uses: 1. A 2nd-order natural sampled - BD – Double-sided (NBDD) modulated loop that includes a low-noise fully differential 1st integrator, and two differential 2nd integrators followed by double differential comparators; The proposed structure also eliminates the requirement of any battery dependent common-mode voltages inside the loop [1]. 2. Cascoded power stage to solve reliability issues due to direct battery

👥 作者与机构

Sreekiran Samala, Vineet Mishra, Kalyan Chekuri Chakravarthi

Texas Instruments, Bangalore, India