SEMICONDUCTOR INTEGRATED CIRCUIT

摘要

PURPOSE:To shorten testing time in a semiconductor integrated circuit device using an internal voltage drop circuit by additionally providing a function for substantially interrupting operation of the voltage drop circuit conformably to a particular control signal and operating an internal circuit by power supply voltage supplied from an external terminal. CONSTITUTION:A title device additionally includes a function which receives power supply voltage VCCE supplied from the outside and includes a power supply circuit VCIG for forming operating voltage VCL for internal circuits CB1 and CB2 lower than said VCCE, and further circuit VCLG is substantially interrupted conformably to a particular control signal and the internal circuits CB1, CB2 are operated by the supply voltage VCCE supplied from an external terminal. For example, the internal voltage drop power supply circuit VCLG receives the power supply voltage VCCE such as about 5V supplied from the outside and forms the drop voltage VCL such as about 3.3V region for the operation of the internal circuits CB1, CB2. A function is additionally provided on the internal voltage drop power supply circuit VCLG, in which an output thereof is made high impedance by a control signal supplied from a control terminal C.