一种单片集成式光-频率转换芯片

Design of Monolithic Integrated Light-to-Frequency Chip

介绍了一种单片集成式光-频率转换芯片,给出了流片芯片的测试结果。芯片内部光电二极管产生随光强变化的光生电流,积分电容将其转换为电压信号,当电压达到比较器阈值时,比较器翻转,振荡电路振荡,光强被转变为频率信号。采用0.6μm 2P3M工艺进行了流片,实现了芯片在三端封装条件下的正常工作,芯片尺寸为1.8mm×1.7mm,光敏区面积为850μm×850μm,非线性小于1%,暗电流小于1Hz,输出信号占空比为50%,芯片最高输出频率为1MHz。

A monolithic integrated light-to-frequency chip was designed,and the chip test results were given.The photo current inside the photodiode varies with the intensity of light,and it will be converted to be voltage signal with the integrating capacitor.When the voltage reaches the threshold of the comparator,the comparator flips,the oscillator oscillates,and the light intensity will be converted into a frequency signal.Chips were fabricated with 0.6μm 2 P3 M process,and experimental results indicate that they can work normally under three-terminal packaging conditions with the chip size of 1.8 mm×1.7 mm,photodiode area of 850μm×850μm,nonlinearity of less than 1%,dark current of less than 1 Hz,output signal duty cycle of 50%,and the maximum output frequency of 1 MHz.