用于超外差接收机的低压、低功耗高动态范围CMOS线性可变增益放大器

针对超外差接收机的自动增益控制网络,设计了一种结构简单的低压、低功耗全差分可变增益放大器.它由6级子电路级联而成,提供范围为81dB的数字控制增益,每一档为3dB,增益误差小于0.5dB.该电路工作于中频300kHz下,工作电压为1.8V,功耗仅为1.35mW.采用TSMC 0.18μm 1P6M CMOS工艺制造,芯片面积约为0.24mm2,低功耗及小芯片面积使其极适用于便携式通信系统的应用.测试结果达到设计要求.

A Low-Voltage,Low-Power CMOS High Dynamic Range dB-Linear VGA for Super Heterodyne Receivers

This paper presents a low-voltage low-power variable gain amplifier,which is applied in the automatic gain control loop of a super heterodyne receiver.Six stages are cascaded to provide an 81dB digitally controlled gain range in a 3dB step.The gain step error is less than 0.5dB.It operates at an intermediate frequency of300kHz,and the power consumption is 1.35mW from a 1.8V supply.The prototype chip is implemented in a TSMC's 0.18μm 1P6M CMOS process and occupies approximately 0.24mm2.It is very suitable for portable wireless communication systems.The measurement results agree well with the system requirements.