| 摘要 |
<p>A circuit regulates the frequency of an oscillator to a digitally presented required value in which the oscillator frequency is determined digitally by a frequency counting circuit and an error signal is derived from a comparator, which is converted to an analogue correcting voltage. The digital values are each divided into sets of values for each of which a digital error signal is derived and used to control the charging current of a capacitor. The charging currents from all sections are fed to a common capacitor whose total charge represents the total error signal. The sets of values may correspond with the decades of the frequency count and the fees to the charging capacitor weighted according to the decade valency.</p> |
