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  1. #1
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    V-PNP as common-collector only?

    Guyz

    Need help. I've read that V-PNP advantage is better speed than L-PNP while L-PNP has less noise than V-PNP. But V-PNP has smaller size, and this extra advantage that makes V-PNP looks better than L-PNP.

    But, in term of cross-section wise, the V-PNP substrate is connected to GND so V-PNP has to be used as common-collector.
    Does this the reason that limit the usage of V-PNP?
    Or is the V-PNP can actually be use as common-emitter?
    In circuit design, which is prefferd, L-PNP or V-PNP?

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  2. #2
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    Re: V-PNP as common-collector only?

    You could use the "Substrate PNP" as emitter follower. But depending on buried layer doping you will get low beta. Further minorities are generated and could be collected by other NWELL and trigger circuit mailfunction. So isolating NWELL guard ring are mandatory.


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