Comparison circuit having programmable hysteresis
US4072870A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 30, 1976 |
| Grant date | Feb 7, 1978 |
| Priority date | — |
| Expiry date | Jun 30, 1996 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K3/2897
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A differential amplifier circuit suitable to be fabricated in monolithic integrated circuit form and having externally programmable, symmetrical input hysteresis. The differential amplifier circuit includes a differential input stage having a resistor coupled between the emitters of the differential transistors. A steering circuit comprising a second differential stage is connected across the resistor at the outputs of the collectors thereof. A differential to single ended converter circuit is utilized to provide output drive to an output multiple collector transistor from the differential input stage. A switching circuit is coupled between one collector of the output transistor to the steering circuit for selectively switching this circuit for steering current through the resistor. An external voltage is coupled across a component of the steering circuit for deriving temperature independent hysteresis. By switching the steering circuit, symmetrical hysteresis is obtained about a given level.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.