| 摘要 |
<p>A digital phase-locked loop using a binary overflowing accumulator as a numerically controlled oscillator 1 has external compensation to eliminate frequency-dependent phase offset problems while not requiring any second-order filtering. Operation of NCO adder 1 initiates with a value set by centre frequency control 2 and under the latching action of latch 4 clocked by reference oscillator 5 produces a linearly stepped output. Detection of the most-significant bit values produces a square wave at output 6. Phase detector latch 9 is used for phase correction, while comparator 13 eliminates steady-state phase error.</p> |
