Question: How do I bring out the VDAC8 output in PSoC 3? Can I connect the VDAC8 output directly to a pin?
Answer: VDAC8 in PSoC3 is implemented by using and IDAC and an internal Load resistance of 16K for 4V range and 4K for 1V range. Following is the block diagram.
If the VDAC8 output is used to drive a resistive load, the load resistance will act in parallel to the internal load resistance and will change the output of the VDAC8. Under this situation, the output of the VDAC8 should be buffered using an unity gain amplifier and connected to a pin. Below is the schematic.
If the VDAC8 output is used to drive a high impedance load then there should be no problem in connecting the VDAC8 output directly to a pin.