BICMOS logic circuit with full swing operation
US5010257A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 13, 1990 |
| Grant date | Apr 23, 1991 |
| Priority date | — |
| Expiry date | Mar 13, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K19/09448
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
According to the present invention, a CMOS interface circuit (C2) similar to a latch made by two CMOS cross coupled inverters (INV1, INV2) is placed directly on the output node (14) of conventional BICMOS logic circuit (11) operating alone in a partial swing mode. This latch is made of four FETs P5, P6, N8, N9 cross-coupled in a conventional way with the feedback loop connected to said output node (14). The partial voltage swing (VBE to VH-VBE) naturally given by the output bipolar transistors (T1, T2) mounted in a push pull configuration is reinforced to full swing (GND to VH) by the latch at the end of each transition. The state of the output node if forced by the latch because of the high driving capability due to the presence of said output bipolar transistors (T1, T2). As a result, the improved BICMOS logic circuit (D2) has an output signal (S) that ranges within the desired full swing voltage at the output terminal (15). It is a characteristic of this embodiment that the structure of CMOS interface (C2) is always independent of the logic function implemented in the conventional BICMOS logic circuit (11). More generally, the CMOS interface circuit may have various physical imp…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.