| 摘要 |
An enhancement for a phase locked loop, where the enhanced phase locked loop includes a phase detector having an output and first and second inputs, the enhancement circuits of the invention, a loop filter and a voltage controlled oscillator having a control signal input and a signal output connected to the second input of the phase detector. One embodiment of the enhancement comprises a first amplifier for amplifying the output signal from the phase detector, a matched quad diode array having first and second nodes, a second amplifier and first, second and third resistors each having first and second terminals. The first terminal of the first resistor is connected to the first terminal of the third resistor and also connected in common to the first amplifier output. The second terminal of the third resistor is connected to the second node of the quad diode array, the first terminals of the first and third resistors and the inverting input of the second amplifier. The second amplifier's output is connected to the second terminal of the second resistor and further connected to the loop filter input. The loop fitler is, in turn, connected to the control signal input to complete the circuit for the enhanced phase locked loop. In operation, the control signal responds to variations in forward conductivity of the matched diode array which, in turn, responds to the voltage swings of the amplified phase detector output.
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