| 摘要 |
PROBLEM TO BE SOLVED: To reduce comparison frequency noise leakage from a PLL-IC and to improve operation stability by performing flip chip mounting of a PLL circuit component on a circuit board as a PLL-IC bare chip. SOLUTION: A PLL-IC bare chip 2 is subjected to flip chip mounting on a circuit board 1 through lands 3a and 3b for connection on the rear face of the bare chip 2 and lands 4a and 4b on the circuit board 1. A signal oscillated from a VCO 6 is outputted externally as an output signal and on the other hand, it is inputted to the bare chip 2 as a feedback signal. And, in a phase comparator in the bare chip 2, the phase difference between the feedback signal having a specific frequency and a reference signal is detected and is outputted to a charge pump circuit, and a control signal is generated so as to perform phase synchronization. A noise component is removed from the control signal through a low pass filter 5 and then, it is feedbacked to the VCO 6. |
