Phase locked loop having automatic free running frequency adjustment

摘要: The capture range and stability of a phase locked loop are improved by adjusting the free running frequency voltage controlled oscillator in response to output signal loop. is filtered amplified, then compared reference from which indicative frequency. A direct current level circuit compares amplified with generates control adjusts so as equalize signal. generated sequentially consecutively enabling series filter reset circuits. switch controls two feedback paths between detector oscillator. first path includes low pass selected for normal operation. During operation, second path, DC converter, selected. select circuit.