| 摘要 |
PURPOSE:To obtain a high speed as well as a wide dynamic range and at the same time to ensure a latching function by using two differential sense amplifiers and applying a positive feedback between these two sense amplifiers. CONSTITUTION:It is supposed that digit lines D and D' are precharged. In such a case, the potential of an output terminal O is decided by the ON resistance ratio between a PchMOSFET11 and NchMOSFET13 and 15. So is with a terminal O'. Here NchMOSFET25 and 15 function as constant current sources respectively. If an address is selected and a difference of potential is produced between lines D and D', either one of these two lines is changed to a high level with the other changed to a low level respectively. The sensitivity of a sense amplifier is increased since the working points of both FET15 and 25 are at a saturated region. In such a way, a positive feedback is applied to two differential amplifiers to invert the output at a high speed. |
