摘要
CMOS运算放大器是红外探测器系统读出电路的重要模块,其性能直接影响红外读出电路性能。本文设计了一款适用于高速读出电路的输出级运算放大器,在负载电阻100 kΩ,负载电容25 pF的条件下,使读出电路的工作频率大于20 MHz。输出级运算放大器由折叠共源共栅差分运放和甲乙类推挽反相运放级联构成。折叠共源共栅差分运放可以实现电路高增益、大输出电压范围和高输出阻抗,同时可以有效减小放大器输入端的米勒电容效应。甲乙类推挽反相运放具有高电压电流转换效率,可以灵活地从负载得到电流或者向负载提供电流,实现高电流增益,驱动大负载。两级运放之间通过米勒电容实现频率补偿,保证运放的稳定性。本文设计的高速输出级运算放大器基于SMIC 0.18μm工艺设计,最终实现指标:功耗不大于10 mW,运放增益>84 dB,相位裕度79°,单位增益带宽>100 MHz,噪声78μV(1~500 MHz),输出电压范围1~5 V,建立时间<15 ns。通过设计高速输出级运算放大器,红外读出电路的读出速率和帧频得到有效提高。
CMOS operational amplifier(OPA)is an important module of the infrared detector system readout circuit, its performance directly affects the infrared readout circuit performance.In this paper, an output stage OPA for high-speed readout circuit is designed.With a load resistance of 100 kΩ and a load capacitance of 25 pF,it allows the readout circuit to operate at a frequency greater than 20 MHz.The output stage OPA consists of a folded cascode OPA and class AB push-pull reversed phase OPA.Folded cascode OPA can achieve high gain, large output voltage range and high output impedance of the circuit, while effectively reducing the Miller capacitance effect at the amplifier input.Class AB push-pull reversed phase OPA has high voltage current conversion efficiency and can flexibly draw current form or supply current to the load, achieving high current gain and driving large loads.The frequency compensation between the two stage amplifiers is achieved by Millar capacitor compensation to ensure the stability of the amplifier.The high-speed output stage OPA designed in this paper is based on the SMIC 0.18 μm process, it can implement parameters: power consumption<10 mW,gain>84 dB,phase margin is 79°,unit gain bandwidth>100 MHz, noise is 78 μV(1~500 MHz),output voltage range is 1~5 V,and the setup time is <15 ns.By designing a high-speed output stage OPA,the readout rate and frame rate of the infrared integrated detector system readout circuit are effectively improved.
作者
张露漩
李敬国
袁媛
ZHANG Lu-xuan;LI Jing-guo;YUAN Yuan(CETC Electro-Optics Technology Co.Ltd.,Beijing 100015,China)
出处
《激光与红外》
CAS
CSCD
北大核心
2022年第9期1407-1410,共4页
Laser & Infrared
