一种面向光隔离放大器的高分辨率接收端电路

A High-Resolution Receiver Circuit for Optical Isolation Amplifiers

面向数字型光隔离放大器芯片应用,设计了一款高分辨率和全集成的接收端电路。基于斩波稳定带隙基准源和数据恢复电路进行电路设计。带隙基准源采用斩波稳定运算放大器结构,减小了电路在低频的闪烁噪声;数据恢复电路包括二阶无源滤波器和二阶多重反馈滤波器,在保证最大平坦响应的同时,将发送端的脉冲密度调制编码进行恢复,输出高分辨率的模拟信号。接收端电路采用CMOS 0.18μm 1P6M工艺进行设计,后仿真结果表明,电源电压为5 V时,接收端电路输入信号最大摆幅为2 V,有效信号带宽为100 kHz,输出信噪失真比(SNDR)达到65.3 dB,有效位数(ENOB)为10.56 bit。

A high-resolution and fully-integrated receiver circuit for digital optical isolation amplifier chip was designed.The circuit was designed based on chopper-stabilized bandgap reference and data recovery circuit.The bandgap reference adopted a chopper-stabilized operational amplifier structure to reduce the flick noise of the circuit at low frequency.The data recovery circuit included a second-order passive filter and a second-order multiple feedback filter,which can recover the pulse density modulation code of the transmitter and output high-resolution analog signals while guaranteeing the maximum flat response.The receiver circuit was designed based on CMOS 0.18μm 1P6M process.The post-simulation results show that at a supply voltage of 5 V,the maxium input swing of the receiver circuit is 2 V,the effective signal bandwidth is 100 kHz,the output signal-to-noise-and-distortion-ratio(SNDR)achieves 65.3 dB,and the effective number of bits(ENOB)reaches 10.56 bit.