| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a frequency synthesizer circuit which can be tested easily in a wafer-probing test before setup, without the terminal of a voltage control oscillator outputting signals to the outside. <P>SOLUTION: A single chip, which is made by mounting a PLL circuit 1, a voltage controlled oscillator 2, and a low-range filter 3, is equipped with a test means 4, which applies binary DC voltage for testing to the voltage control oscillator 2, thus the propriety of the circuit can be decided, based on the oscillation signal outputted from the voltage controlled oscillator 2 by the application of the binary DC voltage, and the test targeting this frequency synthesizer circuit 10, especially the oscillation frequency confirming test targeting the voltage controlled oscillator 2 can be carried out via the test means 4 before assembly, without arranging an external terminal in the voltage controlled oscillator 2. <P>COPYRIGHT: (C)2004,JPO |
