| 摘要 |
PURPOSE:To easily select a device provided or not provided with an optional function corresponding to a request of customers by a method wherein an optional circuit and an optional function selecting pad connected to a part of the optional circuit are previously formed in a semiconductor chip. CONSTITUTION:When an optional function selecting pad 2 is not connected with a VEE lead 3 through a bonding wire 4 in a wire bonding process, or when the optional function selecting pad 2 is in a free state, a power supply circuit 1 serves in such a manner that a potential of a point P becomes higher than VEE by a forward voltage of diodes D3 and D4. That is, at this point, the potential of the point P becomes equal to the saturation voltage of a transistor Tr. In result, the transistor Tr is turned ON. On the other hand, when the optional function selecting pad 2 is connected with the VEE lead 3 through the bonding wire 4, the potential of the point P becomes equal to VEE, and as the VEE is lower than the saturation voltage of the transistor Tr, the transistor Tr is made to be turned OFF. |
