Re: trying to understand the design of op-amp
- --- In email@example.com, "tomshong" <tomshong@...> wrote:
>Check here: http://groups.yahoo.com/group/softrock40/message/66096
> I see the op-amps in RX II are wired such that its `high' is connected to VDD, and `low'is connect to ground, and that tells me it should only be able to operate between VDD and ground.
> Yet, when I ran transient simulation in LTspice, shows the output voltage swings such that it's going between + and range.
> I see there are the DC-blocking cap, C46 and C47, at the output of the Op-Amp. It seems, after that point, only the AC component will pass through, and will be biased to whatever is after the cap.
> So why is the op-amp is designed such that the output drops to the negative range when the op-amp is biased between VDD and ground?