A second circuit coupled to the oscillator is arranged for receiving {HEAD ~ an externally provided frequency reference input} at {TAIL ~ a second input node} 
at
A second circuit coupled to the oscillator is arranged for receiving { HEAD ~ an externally provided frequency reference input } at { TAIL ~ a second input node }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL