| 摘要 |
<p>PURPOSE:To make it possible to achieve effective utilization without decreasing the number of signal terminals, which are used in normal operation, and without a special input terminal for a test control signal by controlling the function test in a semiconduc tor integrated circuit device with the potential of a power supply terminal on the high-potential side of an emitter follower output circuit part. CONSTITUTION:A test control signal at the level, of a potential, which is lowered to the lower side by the forward voltages between the bases and emitters of transistors T1 and T2 from the potential of a second higher-potential-side power supply wiring 2 is outputted to a test control signal terminal 5. At the normal time, the potentials of the higher-potential-side power supply wirings 1 and 2 in an emitter coupled logic circuit are made to be the ground potential (0V), and the potential of a reference power supply terminal 6 is made to be about -1.3V. At this time, the potential at the terminal 5 when the forward voltages between the bases and the emitters of the transistors T1 and T2 become -1.6 V, and the terminal 5 becomes the low level. Therefore, when the device is constituted so that the normal mode is set when the terminal 5 is at the low level and the test mode is set at the high level, the semiconductor integrated circuit device becomes the normal operation mode under the normal using conditions with the wiring 2 at the ground potential.</p> |
