文档介绍：华中科技大学
硕士学位论文
AB类折叠共源共栅CMOS功率放大器设计
姓名:陈曙
申请学位级别:硕士
专业:微电子学与固体电子学
指导教师:刘三清
20050401
摘要
低成本高品质的耳机驱动功率放大器一直是消费类电子诸如播放器
和等产品所追求的目标大多数传统的音频功率放大器是用双极型工艺设计和制
造其基础在于良好的双极型三极管特性虽然技术具有低成本的优点但是
较大的输出管尺寸驱动低阻抗负载时稳定性问题驱动高容性负载时带宽问题以及
噪声干扰等一直限制了应用技术的前进步伐
近年来随着集成电路技术的高速发展上述问题在很大程度上得到改善
本论文在设计高开环稳定性类共源共栅功率放大器的过程中首先从电路的
基本结构着手根据设计指标确定符合要求的共源共栅电路形式然后用功率预算和
电流分配的方法设计器件参数最后利用计算机仿真结果显示放大器单位增益带
宽达到静态电流为在负载的情况下最大输出电流可以达到
放大器低频开环增益为相位裕度高达为显示
出优良的闭环稳定性和抗电源噪声干扰能力在电源供电的情况下输出电压摆
幅达到另外为了改进功率放大器输入电压范围一种互补折叠式共源共栅
结构代替原有的共源共栅结构在电路性能没有降低的情况下输入信号范围达到端到
端输入
最后芯片内部独特设计使得输出端去掉了耦合电容实现连接进一步减
小了系统体积

关键词共源共栅结构单位增益带宽相位裕度电源电压抑制比
III
ABSTRACT
Audio players such as popular CD, MP3 and DVD in the consumer electronic market
have driven for low cost and high performance headphone power amplifiers. Majority of
conventional power amplifiers are designed using bipolar technology on the basis of
well-known merits of bipolar transistors. Although CMOS technology offers low cost
alternative, they suffer major problems such as large size in output transistors, stability
issues on driving low resistive in parallel with high capacitive load at high bandwidth, noise
and so forth.
Recently, with the fast development of CMOS technology, such problems have been
solved in many aspects. In this paper, a class AB Cascode CMOS power operational
amplifier with stable open-loop gain is presented. First a proper selected Cascode amplifier
structure is used in order to satisfy the design target, and then by using the method of power
and current budget, appropriate device parameter is received. The simulated result shows
that the unity gain-bandwith is 31 MHz, the quiescent supply current is and the
output stage delivers maximum 50mA into a 32Ù load. The amplifier exhibits a
open-loop gain at low frequency, phase margin is up to 108°, PSRR is 78dB and
output at a supply in a ìm CMOS technology.
On the other hand, in