| 摘要 |
PURPOSE:To reduce the power consumption by providing a circuit which inhibits the current supply to a peripheral circuit if a prescribed voltage considerably higher or lower than the normal input level is applied to a prescribed input terminal. CONSTITUTION:The base of a current controlling transistor TR 18 of a current source which supplies a current to a peripheral circuit 16 is connected to a reference voltage generating circuit 20, and normally, such control is performed by a reference voltage VR outputted from this circuit 20 that the supply current is kept constant. The reference voltage generating circuit 20 is connected to a prescribed input terminal 22, for example, a chip select signal input terminal essentially provided in an ECL RAM 10. If the prescribed voltage considerably higher or lower than the normal input level is applied to the input terminal 22, the reference voltage generating circuit 20 sends a signal, which cuts off the current supply to the peripheral circuit 16, to the TR 18. |
