| 摘要 |
PURPOSE:To facilitate acceleration of burn-in, by imparting a first voltage only when the potentials of a plurality of external input terminals are located within a specified region at the same time. CONSTITUTION:The input and output parts of a main circuit 1 are constituted so that the levels of signals can be converted. Only the output part is driven with the voltage of an external power source. The main circuit 1 is set so the that the circuit is normally operated with an internal voltage that is lower than the voltage of the external power source, which is imparted to a pair of external power source terminals 3 and 4. When the potential of an external input terminal 9, which imparts a signal to the main circuit 1, is located Within a specified region but outside of the normally operating range, the potential is detected by a control circuit 20. Then, a power source circuit 30 imparts the first voltage, which is higher than the internal power source voltage, to internal power source terminals 2 and 3a of the main circuit 1. Thus, acceleration in burn-in can be performed. |
