Connecting the output of SCBLOCK to Input of CT Block


Question: How should the output of an SCBLOCK be routed to the input of a CT block?


Response: The output of an SC Block is not continuous and is switching in nature (Refer AN2041 for details of Swtiched Capacitor theory).  Because of this the output of an SC Block cannot be directly connected to the input of a CT block.  To get a stable otuput from an SC Block, the output has to be passed through a sample an hold circuit, which is present in the analog out bus.  So, either connect the output of the SC Block to the analog bus and use the Analog Bus as the input to CT block, or if the CT block is in a different analog column, route the signal to an external pin and connect to the CT block through this pin.