jqjqjq
Newbie level 4
Hi everyone,these days I'm designing a low-voltage low-power operational amplifier which expected to have rail to rail input range and output range.
However,after simulation, I didn't achieve what I want. I wondered what should I do to modify the parameters of my schematic.
The result vcm-vo figure is:
It followed from the figure that the smaller the load resistance, the less ability that vo achieve the negtive rail. And vo can not achieve the positive rail, either, which seemed to have less relation with the load. What is the reason?
ps:The common input is from -0.75V to 0.75V, VDD is connected to 0.75V, while VSS to -0.75V, and the load is swept from 100 to 10K, whose another node is short to the ground.
Thanks in advance for any help and please forgive my syntactic error.I'm not from English-speaking country.
However,after simulation, I didn't achieve what I want. I wondered what should I do to modify the parameters of my schematic.
The result vcm-vo figure is:
It followed from the figure that the smaller the load resistance, the less ability that vo achieve the negtive rail. And vo can not achieve the positive rail, either, which seemed to have less relation with the load. What is the reason?
ps:The common input is from -0.75V to 0.75V, VDD is connected to 0.75V, while VSS to -0.75V, and the load is swept from 100 to 10K, whose another node is short to the ground.
Thanks in advance for any help and please forgive my syntactic error.I'm not from English-speaking country.