Precision Clock Control System


This project consisted of a quadruple control system in embedded firmware using a microcontroller and other mixed signal circuits.


  • Coordinate operation and timing of 4 simultaneous digital feedback control systems.
  • Maintain temperature of a cesium cell
  • Maintain temperature of a VCSEL laser.
  • Apply appropriate stable bias to laser.
  • Apply various modulation frequencies to the laser.
  • Detect responses to the applied modulation frequencies.
  • Apply intelligent algorithm to detect specific nonlinear transitions in system
  • Adjust a precision local oscillator clock according to responses



A DSP algorithm was used to detect certain nonlinear transitions. A nonlinear mathematical model was created to assist the algorithm with the detection process. The transitions were used as feedback to achieve certain set points in the quadruple feedback control system. The system achieved clock setting and stability in the few parts per million.
System was delivered to the customer accompanied with a Graphical User Interface to assist in further Research.