A 1.2mW 1.6Vpp-Swing Class-AB 16Ω Headphone Driver Capable of Handling Load Capacitance up to 22nF

📋 论文概要

本文提出了一种低功耗Class-AB耳机驱动器，能够驱动高达22nF的容性负载，适用于便携设备中的ESD保护和EMI抑制。通过新的频率补偿方案，实现了比传统嵌套米勒补偿（NMC）方案高10倍以上的功率效率，同时避免了频率响应的尖峰和不稳定问题。

💡 主要创新点

• 提出了一种适用于三级放大器驱动大容性负载的新型频率补偿技术，消除了传统方案中的尖峰和不稳定问题。
• 实现了1.2mW超低功耗、1.6Vpp摆幅，驱动16Ω耳机和22nF电容，功率效率比NMC方案提高10倍以上。
• 设计了一款通用的低功耗耳机驱动器，兼容多种便携平台，减少了设计周期。

🏷 关键词

📄 原文摘要

A versatile low-power headphone driver that can be used in a variety of portable electronic devices is desirable for compatibility and to reduce design-cycle time. Capacitive loads as large as 20nF are used in some platforms for ESD protection and EMI suppression. Several compensation schemes for 3-stage amplifiers driving large capacitive loads with power efficiency more than 10 times that of the conventional nested Miller compensation (NMC) scheme have been reported recently [1-3]. However, all of these schemes are vulnerable to large peaking in their frequency response and potential instability when the load capacitance is dropped to smaller values, which may be the case in other platforms. We present a compensation scheme with a damping circuit that automatically adjusts according to the load condition to overcome this problem and still maintain the power efficiency improvement over NMC.

👥 作者与机构

Vijay Dhanasekaran, Jose Silva-Martinez, Edgar Sanchez-Sinencio

Texas A&M University, College station, TX