| 摘要 |
PROBLEM TO BE SOLVED: To provide a down-sized oscillator capable of reducing problems, such as test impossibility due to a voltage drop even when high voltage is applied to a vibrator output connection terminal and reducing test modes not functioned by supply voltage having high threshold voltage of a test circuit.SOLUTION: In a test of a circuit to be tested (an output buffer 25) of an oscillator circuit 2 including: a test circuit 1; an Enable/Disable control terminal OE; a vibrator input connection terminal XIN; a vibrator output connection terminal XOUT into which test voltage is inputted; and first and second output terminals OUT and OUTN, a test mode is formed by setting the OE terminal to a L voltage and the XIN terminal to a H voltage, and a state of the circuit to be tested is tested by applying the H voltage or the L voltage to the XOUT terminal. An inverter 12 of the first stage inputted by an input signal from the XOUT terminal in the test circuit 1 reduces the threshold voltage of the inverter into less than a half of the supply voltage. The inverter 12 is a resistance load type. |
