Two-Device Nondestructive Read-Out Cell With Stacked Metal Oxide Semiconductor Devices
Original Publication Date: 1986-Mar-01
Included in the Prior Art Database: 2005-Mar-08
This article describes a stacked metal-oxide-semiconductor (MOS) dynamic cell structure featuring a nondestructive read-out (NDRO) capability. The cell may be formed in dense layout. Stacked MOS structures are proposed to achieve dense layouts of the basic two-device cell shown in Fig. 1. The concept consists of storing the information as an electrical charge on the gate of an NMOS sense device T1 using a PMOS write device T2 and a write enable line W/W. This allows for non-destructive DC read out. Referring to Fig. 2, information is written into a selected wordline by bringing both the word line W/R and the write line W/W to VH and providing the data on the bit line B/L as a zero or VH potential. This charges capacitor C1 (node G) either negatively (-VH + VTP) or to zero with respect to W/R.