9 Multiphase Output

Additional coherent phases may be derived from the same shift register. By driving additional resistor networks with delayed outputs 2, 3, 4 or more phased outputs can be created. The 6-bit Johnson counter is the shortest length that can create 2, 3, or 4 phase outputs, even simultaneously when driven as shown throughout Figure 8-1.

Figure 9-1 6-bit Johnson Counter can Generate Various Useful Phase Relationships; 90°, 120°, 180°, 240°, 270°

The simulation results of Figure 8-1 are found in Figure 8-2. For simplicity, output filtering has been omitted from these results. Note that variation in harmonic filter components can cause unwanted phase shift between outputs.

See the Voltage Mode Operation and Open-Circuit Output Transient Response circuit in Figure 6-1.

Figure 9-2 Multiphase Output Simulation