基于线性频率调制与解调的片上直流电压信号放大器

摘要

To amplify the DC signal is a discommodious issue, because of the on-chip DC signal has such properties as little swing, less coherence and likeliness to be interfered. In light of this, a "voltage-frequency-voltage" mode DC signal amplifier is proposed, in which the frequency is the carrier signal. This amplifier is highly linear, and is equipped with a high linearity "voltage-frequency" modulator and a "frequency-voltage" de-modulator. The simulation experimental results show that the DC signal amplifier amplifies the input voltage signal efficiently while achieving stable high linearity, and the DC gain is 2.4.%片内直流电压信号摆幅较小,且受到CMOS工艺中被动器件一致性较差、易被高频交流信号干扰等因素的影响,采用典型的比例放大电路难以放大这类信号.为此提出了一种基于“载频”的“电压→频率→电压”放大方法,使用载波信号作为片上长距离传输的信号,将易受到干扰的直流信号局部化,利用前馈补偿技术构建了具有高度线性转换关系的“电压→频率”调制电路,采用具有较高线性度的频率解调电路实现后级电压信号的解调,有效地放大片内直流电压信号.电路仿真结果表明,所提出的放大器电路能有效地放大片上电压信号,直流电压增益为2.4.