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BIASING
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lordvader88:

--- Quote from: virtualparticles on June 19, 2019, 02:24:53 pm ---Diode D1 is indeed there to allow fast logic switching while R2 and C1 and C2 filter the noise. Noise voltage is assumed to be low enough to not turn on the diodes but a real logic signal will turn on the diode and fly over R2.



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So you mean as a way to bypass the resistor and allow the cap to drain or charge through the diode when the state changes ?


OP it's also a 'clipper circuit' when ,back-to-front diodes are across something, they would try and limit the max voltage across the resistor to the diode's voltage drop...until they burn out.
David Hess:

--- Quote from: Nikos A. on June 19, 2019, 11:17:08 am ---1. Why the designer uses VSS to indicate ground? Is there any specific reason?
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Vss is shorthand for the substrate connection which in a common junction isolated process, must be at the most negative potential or lower.  So usually this connection is made to ground or the negative supply but it may or may not be common for the IC.


--- Quote ---2. What is the purpose of anti-parallel diodes at this case? https://www.infineon.com/dgdl/Infineon-BAS125SERIES-DS-v01_01-en.pdf?fileId=db3a304314dca389011518d610ec0e15
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I think those are intended to speed up switching of the level shifter so power may be applied or removed more quickly without waiting for the 10 kilohm resistor to charge or discharge C1 and C2.  But I think this could have been designed better if that was the goal.


--- Quote ---3. What is the purpose of the complementary transistors at this case? https://www.diodes.com/assets/Datasheets/ZXTC2062E6.pdf
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They are configured as a level shifter to power the amplifier when enabled by a logic level signal.
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