SBOA550 October   2022 OPA1671 , OPA2990 , SN74HCS04 , SN74HCS164 , SN74HCS30 , SN74LVC1G00 , SN74LVC1G123 , TLC04 , TLC14 , TS5A9411

 

  1.   Abstract
  2.   Trademarks
  3. 1 Introduction
  4. 2 The Davies Generator
  5. 3 Optimizing Standard Resistance Values for THD Performance
  6. 4 Simulation Examples
  7. 5 Compensating for Shift Register Output Resistance
  8. 6 Voltage-Mode Thevenin Equivalent
  9. 7 Harmonic Filtering
  10. 8 Tracking Harmonic Filter
  11. 9 Multiphase Output
  12. 10Conclusion
  13. 11Acknowledgment
  14. 12References
  15.   A Analytical Solution for Resistance Network Values
  16.   B Forbidden States of the Johnson Counter

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.

Figure 9-2 Multiphase Output Simulation