一种12-bit 1MSPs SAR ADC的设计

A Design of a 12-bit 1MSPs SAR ADC

设计了工作在5 V单电源电压下,典型采样速度为1 MSPs的12位低功耗逐次逼近型模数转换器。设计中D/A转换器采用了加电容分压器的电荷分布式结构,在扩展并行D/A转换器分辨率的同时大大节省了芯片面积,内置的3.3 V参考电压源采用自偏置的供电方式,提高了基准电压的精度,同时也降低了功耗。使用cadence spectre工具进行仿真,后仿结果表明,设计的D/A转换器、3.3 V基准源满足12 bit A/D转换的要求,逐次逼近A/D转换器可以正常工作。

A 12-bit low power SAR A/D converter with medium speed is designed,which can work under a 5 V power supply.A charge scaling D/A converter with capacitor voltage divider is designed,which extends the resolution of a parallel D/A converter as well as reduces the chip area.Built-in 3.3V self-biasing reference voltage source improves the accuracy of the reference voltage,and also reduces power consumption.The simulation result shows that the reference voltage source and the D/A converter meet the requirements of the 12-bit A/D converter,and the SAR A/D converter can work well.