L
[email protected]
- Jan 1, 1970
- 0
Hi,
with your help, i've designed an opamp folded cascode with a fixed
capacitive load....now i want to make an output (mosfet) stage voltage
follower-voltage follower....My output stage is composed by 2 voltage
follower output transistor, each of them piloted by a mosfet current
source (or sink) and a common drain...the gate of the 2 common drain
are connected to folded cascode's capacitive load. I don't understand
a strange problem that i've found.
1)If, before to connect output stage to folded cascode,i connect an
ideal ac source to buffer stage and an output load, i obtain the
desidered output stage's pole frequency
2)if i connect folded cascode's load (instead ac source), buffer pole
has a lower frequency (folded cascode pole is unchanged)
Why??
Thanks
with your help, i've designed an opamp folded cascode with a fixed
capacitive load....now i want to make an output (mosfet) stage voltage
follower-voltage follower....My output stage is composed by 2 voltage
follower output transistor, each of them piloted by a mosfet current
source (or sink) and a common drain...the gate of the 2 common drain
are connected to folded cascode's capacitive load. I don't understand
a strange problem that i've found.
1)If, before to connect output stage to folded cascode,i connect an
ideal ac source to buffer stage and an output load, i obtain the
desidered output stage's pole frequency
2)if i connect folded cascode's load (instead ac source), buffer pole
has a lower frequency (folded cascode pole is unchanged)
Why??
Thanks