A low-power low-voltage slew-rate enhancement circuit for two-stage operational amplifiers

被引：3

作者：

Chen, Shu ^{[1
]}

Jun, Xu ^{[1
]}

Fan, Ye ^{[1
]}

Ren Junyan ^{[1
,2
]}

机构：

[1] Fudan Univ, State Key Lab ASIC & Syst, Shanghai 201203, Peoples R China

[2] Fudan Univ, Microelect Sci & Technol Innovat Platform, Shanghai 200433, Peoples R China

来源：

JOURNAL OF SEMICONDUCTORS | 2012年 / 33卷 / 09期

关键词：

slew-rate enhancement; two-stage operational amplifier; low-voltage operation; low-power consumption;

D O I：

10.1088/1674-4926/33/9/095007

中图分类号：

O469 [凝聚态物理学];

学科分类号：

070205 ;

摘要：

A novel circuit is presented in order to enhance the slew rate of two-stage operational amplifiers. The enhancer utilizes the class-AB input stage to improve current efficiency, while it works on an open loop with regard to the enhanced amplifier so that it has no effect on the stability of the amplifier. During the slewing period, the enhancer detects input differential voltage of the amplifier, and produces external enhancement currents for the amplifier, driving load capacitors to charge/discharge faster. Simulation results show that, for a large input step, the enhancer reduces settling time by nearly 50%. When the circuit is employed in a sample-and-hold circuit, it greatly improves the spur-free dynamic range by 44.6 dB and the total harmonic distortion by 43.9 dB. The proposed circuit is very suitable to operate under a low voltage (1.2 V or below) with a standby current of 200 mu A.

引用

页数：6

共 16 条

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