Someone could help me? I'm trying to do the OTA tr...
# xschemh
HADASSA JULIANA DA COSTA GOMES
09/30/2023, 2:20 PMSomeone could help me? I'm trying to do the OTA transient simulation
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Boris Murmann
09/30/2023, 5:52 PMWhat's inside the amplifier?
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HADASSA JULIANA DA COSTA GOMES
09/30/2023, 5:58 PMimage.png
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Stefan Schippers
09/30/2023, 6:01 PMTry to increase V1 amplitude to 1.8V
Stefan Schippers
09/30/2023, 6:04 PMIf still not working replace OTA M1 and M2 with pfet_01v8_lvt (set channel length to 0.35, this is the minimum for pfet_01v8_lvt)
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yrrapt
10/01/2023, 8:54 AMThere's a few things that I notice:
1. The amplifier has no feedback so there is nothing to set the DC value of the output, hence it's heading off into the rail.
2. The input common mode voltage (0.9 V) is probably too high for the input stage.
3. The input signal of 1 MHz is a bit high for a first "proof of life" sim in my opinion
Personally, I would start with the amplifier in a buffer configuration (let's hope it's stable) : connect output to input negative. And input positive with a pulse at 1 kHz, 0.45 V amplitude, and a DC offset of 0.45 V