Nurahmad
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Hi,
I'm simulating LDO in Spectre (Cadence). I used 2 methods in simulating the loop stability.
1. Break the loop and add an AC voltage source.
2. Use iprobe instance.
The gain plot is correct, but the phase plot is different in 2 methods. What's more, using method 1, the phase plot starts from "0", regardsless of the load. While using 2nd method, the phase plot starts from "180" at light load, but starts from "0" at heavy load.
Can u explain this phenomenon, where did I got wrong. thank you!
I'm simulating LDO in Spectre (Cadence). I used 2 methods in simulating the loop stability.
1. Break the loop and add an AC voltage source.
2. Use iprobe instance.
The gain plot is correct, but the phase plot is different in 2 methods. What's more, using method 1, the phase plot starts from "0", regardsless of the load. While using 2nd method, the phase plot starts from "180" at light load, but starts from "0" at heavy load.
Can u explain this phenomenon, where did I got wrong. thank you!