一种大带宽、高增益的高速跨阻放大器芯片设计

An integrated high-speed Transimpedance Amplifier chip with broad bandwidth and high gain

摘要:

提出一种可用于高速光接收系统的宽带跨阻放大器(TIA)芯片架构和电路设计。跨阻放大器芯片作为光电探测器后端电路，可对探测器输出的电流信号进行低噪声放大，并使其满足速率和系统灵敏度需求。高速跨阻放大器设计架构由跨阻放大器核心电路、单端到差分转换电路以及限幅放大器电路3部分组成。在限幅放大器设计中，利用密勒效应引入可调电容平衡高频电路输出电压幅度、带宽和电路稳定性，实现信号宽带接收、限幅放大以及外部驱动等功能，提升高速传输信号的质量。通过在不同工艺角下对芯片进行小信号幅频特性分析、噪声仿真及大信号时域分析，进一步验证了跨阻放大器芯片的带宽、噪声和灵敏度以及传输特性等芯片各项性能指标。

Abstract:

A broadband Transimpedance Amplifier(TIA) chip architecture and circuit design suitable for highspeed optical receiver systems are proposed. The TIA chip, as the backend circuit of the photoelectric detector, can amplify the high speed photo-current of the detector with a low input referred noise and meet the requirements of system-level speed and sensitivity. The high-speed TIA design architecture consists of three parts: the TIA core circuit, the single-ended to differential conversion circuit, and the limiting amplifier circuit. In the design of the limiting amplifier, the Miller effect is utilized to introduce tunable capacitors to balance the output voltage amplitude, bandwidth, and circuit stability of the high-frequency circuit, achieving broadband signal reception, limiting amplification, and external driving functions, thereby enhancing the quality of high-speed transmission signals. By conducting small-signal amplitude-frequency characteristic analysis, noise simulation, and large-signal time-domain analysis of the chip under different process corners, the bandwidth, noise, sensitivity and transmission characteristics of the TIA chip are further verified.