The Design Of CMOS Current Operational Amplifier With Highly Reliable

For the past few years,with the progress of society,the further development of the semiconductor industry,and the maturity of the process,the size of the device has developed toward the limit of Moore's Law.In the face of more and more advanced nanotechnology processes,we need to consider more and more effects in circuit design.With the further"sanctions"imposed by the United States on my country's integrated circuit industry in 2020,we are struggling with integrated circuit manufacturing.Facing the current trend of domestic replacement of chips,high-reliability and large-drive current operational amplifiers also play an important role in the drive field.The domestic research on operational amplifiers mainly focuses on general-purpose operational amplifiers,and there are few products that drive operational amplifiers.Although there are many foreign high-current drive operational operational amplifiers,their electrostatic protection levels are low.Therefore,this article will design and implement a high-reliability and large-drive current op amp based on the standard process.Based on the 0.18?m CMOS process,this paper designs a driving operational amplifier with a maximum output current greater than 300m A under a 5V supply voltage and a maximum AC output current greater than 210m A under a 3V supply voltage.In this design,a two-stage amplifier structure is used.The operational amplifier adopts a fully differential structure as the input stage to obtain a suitable open-loop gain,and the second stage of the operational amplifier adopts a Class-AB structure to obtain rail-to-rail(Rail-to-Rail)Output;Three branch reference current sources are used to provide bias for the op amp,and an over-temperature protection module is also added to the circuit based on the characteristic of large drive current output to realize the protection of the circuit;the circuit output stage MOS layout adopts drain widening The drawing method and the addition of ESD devices to improve the ESD protection level.The operational amplifier designed this time can also make the chip enter the sleep mode through the control port to meet the needs of a wider range of applications.The operational amplifier designed in this paper can output a dynamic output current greater than 300m A in the temperature range of-45??125?under 5V supply voltage.When the external environment temperature exceeds 130?,the chip will be shut down;when the external environment drops to 90?,the chip will restart.When resume work,the over-temperature hysteresis interval is 40?.The simulation,layout drawing,tape-out and testing of current operational amplifiers are completed based on the 0.18?m process.The overall layout area is 1050×950?m~2.The actual measurement results can show that the current output of 376m A can be achieved under the 5V power supply voltage,the quiescent current is 900?A,the conversion rate is 2V/?s,the output voltage swing is 0.3?(VCC-0.5)V and the ESD protection level of the output port can reach at 8k V.