| 摘要 |
PROBLEM TO BE SOLVED: To reduce the area and the test time of a semiconductor integrated circuit which mounts a PLL circuit having a current charge pump with a current source supplied from a feedback loop of a base voltage generator circuit. SOLUTION: In a standby for the actual operation, a base clock signal, a feedback clock and a reference clock are alternately inputted to a phase comparator to monitor a lop filter output signal. The current of the output signal is monitored to detect failures of a base voltage generator circuit, a current charge pump and the phase comparator at the same time. |
