Complete PCB Design Using OrCAD Capture and PCB Editor

Example 2. Mixed Analog/Digital Design Using Split Power, Ground Planes

This example shows how to design a circuit with a mixture of analog and digital parts, multiple power planes, and a single Ground plane split into analog and digital sections that have a common reference point.

Mixed-Signal Circuit Design in Capture

Figure 9-90 shows the circuit design example. The circuit consists of a mixture of analog and digital parts, multiple power sources, and separate analog/digital Ground planes. It has an off-board connector, an analog signal conditioning circuit (the op amp U1), an analog-to-digital converter (U2), a digital microcontroller (U3), and a digital serial-to-parallel shift register (U4). Note that the bypass capacitors have been omitted ...