SCR Pull-Up Circuit
Original Publication Date: 1984-Mar-01
Included in the Prior Art Database: 2005-Feb-03
With capacitive coupling technique, it is possible to push a node above the supply voltage. However, there are two major questions to be addressed when using this technique: (1) Can the physical layout be made small enough? (2) Will the coupling always be sufficient under worst-case conditions? Fig. 1 is a known bootstrap circuit. The circuit requires three transistors to layout, and its coupling phenomenon of the B-C diode D1 is somewhat limited. To improve the coupling effect as well as to minimize layout area, the circuit configuration of Fig. 2 is disclosed. In Fig. 3A, the layout of transistors T1 and D1 of Fig. 1 is shown. Fig. 3B shows the integration of these two elements. The Fig. 3B structure results in a 24% reduction in length. However, area saving is not the only claim here.