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@ericfont

ericfont/circuit-20251124-1605.svg

Created November 24, 2025 21:03
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try free-running hi-freq
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ericfont commented Nov 24, 2025

sim, oscillates better 700-900 kHz

super clean PSD:
image

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ericfont commented Nov 24, 2025

seems peak is 400 kHz

image

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ericfont commented Nov 24, 2025

with empty input

image

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ericfont commented Nov 24, 2025

before the first integrator:

image

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ericfont commented Nov 24, 2025

give both opamps a 10mV offset error, then oscillates lower around 200kHz

image

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ericfont commented Nov 24, 2025

sim offset error setup with input sines

image

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ericfont commented Nov 24, 2025

image

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ericfont commented Nov 24, 2025

add 10Mohm feedback

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ericfont commented Nov 24, 2025

image

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ericfont commented Nov 24, 2025

remove offset error and feedback resistors

image oscillates around 250kHz

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ericfont commented Nov 24, 2025

only add offset error to upper integrator

image

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ericfont commented Nov 24, 2025

readd feedback resistor, oscillate around 200 kHz

image

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