Self-referenced current switch logic circuit with a push-pull output buffer
US5089725A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 26, 1990 |
| Grant date | Feb 18, 1992 |
| Priority date | — |
| Expiry date | Oct 26, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K19/013
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
The base circuit comprises a self-referenced preamplifier (31) of the differential type connected between first and second supply voltages and a push-pull output buffer stage connected between second and third supply voltages. The push-pull output buffer stage comprises a pull-up transistor and a pull-down transistor connected in series with the circuit output node coupled therebetween. These transistors are driven by complementary and substantially simultaneous signals S and S supplied by the preamplifier. Both branches of the preamplifier are tied at a first output node (M). The first branch comprises a logic block performing the desired logic function of the base circuit that is connected through a load rsistor to the second supply voltage. The logic block consists of three parallel-connected input NPN transistors, whose emitters are coupled together at the first output node for NOR operation. The second branch is comprised of a biasing/coupling block connected to the second supply voltage and coupled to the first output node and to the base (B) node of the pull-down transistor. This block ensures both the appropriate polarization of the nodes in DC without the need of external …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.