| 摘要 |
PURPOSE:To reduce erroneous operations in mode changing operation, by using one terminal for a function at a normal mode and for a mode changing function. CONSTITUTION:When an input signal RES at an input terminal 2 is set at a 0V level, the output of a Schmitt trigger circuit 8 becomes the 0V level, and an RS flip-flop 6 is reset. A test-mode changing signal TEST becomes the 0V level. This state is a reset state (c) of in a normal mode (a). When the input signal is set at a 5V level, the output of the Schmitt trigger circuit 8 becomes the 5V level, and the reset state is released. The output signal of an inverter 4 is not inverted by the input at 5V. Therefore, the TEST signal of the flip-flop 6 remains at the 0V level. Thus, this state becomes an operating state (d) in the normal mode. When the input signal is set at a 10V level, the output signal of the inverter 4 is inverted, a set input set to the RS flip-flop 6 becomes the 0V level, the TEST signal becomes the 5V level and a test mode (b) is obtained. |
