Tri-state buffer circuit
US4725982A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 28, 1986 |
| Grant date | Feb 16, 1988 |
| Priority date | — |
| Expiry date | Mar 28, 2006 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K19/09448
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A tri-state buffer circuit according to the present invention comprises a switching circuit connected to an input terminal (IN), tri-state and inverted tri-state input terminals (T, T), and a first power supply terminal for generating first and second switching signals (A, B) which have a first and second levels, respectively, only when the tri-state signal is on a first level, regardless the level of the input signal; an inverter circuit connected to said switching circuit, and the first power supply terminal for inverting the first switching signal (A) from said switching circuit as an output signal; a selection circuit connected to said switching circuit and inverter circuit for maintaining a signal, which have a second level, equal to the inverted signal only when the tri-state signal is on first level; a first type bipolar transistor whose base is connected to said inverter circuit, whose collecter is connected to the first power supply terminal, and whose emitter is connected to the output terminal of the tri-state circuit; and a first type bipolar transister whose base is connected to said selection circuit, whose collecter is connected to the output terminal of the tri-stat…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.