Precautions when handling Op-Amp dedicated pins in a PSoC 3/5 design
Last Updated: 06/18/2011
What are the precautions to be taken when handling Op-Amp dedicated pins in a PSoC 3/5 design?
All 4 uncommitted Op-Amps have two pins each dedicated which can be routed to the op-amp inputs. But that doesn’t mean the op-amp has to have its inputs from these input pins only. The op-amp inputs can also be rerouted to the other pins through the analog routing.
The op-amp outputs on the other hand are fixed and dedicated pins in the device. In a four op-amp device the pins P0.0, P0.1, P3.6, and P3.7 are dedicated op-amp outputs. The output of an op-amp always goes to its dedicated pin.
When the op-amp output is routed to a pin other than the dedicated output pin, the dedicated output pin is still going to be connected to the op-amp output along with the pin the user has chosen.
It is to be noted that when the Op-Amp's dedicated output pin is not used, it uses the analog routing structure to route the Op-Amp output to a different pin. This would include a few switch resistances and global resistances making the Op-Amp drive strength lower. The user should be wary about this when his/her application is bandwidth/slew limited.