| 摘要 |
<p>PURPOSE:To realize a high-speed working of a memory device, by providing the thyristor characteristic to a level shifting circuit to be inserted to prevent the device from an erroneous writing during the steady reading action. CONSTITUTION:When the voltage is applied between an input point (a) and an output point (b), an npn type transister (TR) 300 is turned on to flow the base current of a pnp type TR304. Thus the TR304 is turned on. The collector current of the TR304 supplies the base current of the TR300. In other words, both TRs 300 and 302 perfectly turned on, and the voltage between the points (a) and (b) drops. In such way, a level shifting circuit 30a has a noise margin in the steady operation mode and the thyristor characteristic that reduces the impedance in the writing mode is obtained.</p> |
