| 摘要 |
PURPOSE:To select whether there is a pull-up transistor or not only by a depletion process, by constituting a transistor for pull-up in the manner in which a depletion type transistor and an ordinary enhancement type transistor are connected in series. CONSTITUTION:Whether there is a pull-up transistor or not can be selected by whether a MOSTr4 is made a depletion type or not. In many cases, a depletion process is as printing process of ROM data, and it is easy to print on a mask, the selection by computer processing of whether the transistor is made a depletion type or not. Especially for an application in a single chip microcomputer, whether there is a pull-up transistor or not can be detremined for each user together with a ROM. In the case where the MOSTr4 is not made a depletion type, the Tr4 is turned OFF as the gate level of Tr4 is ground, so that there is no pull-up. |
