Input current limit in digital input receivers
US10281946B1 · kind B1 · utility
4Cited by
0References
20Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jun 4, 2018 |
| Grant date | May 7, 2019 |
| Priority date | — |
| Expiry date | Jun 4, 2038 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2200/396
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A bandgap voltage reference is provided in quasi-parallel with a resistor in the input path of a digital input circuit. Because of the quasi-parallel nature, the current used by the digital input circuit is limited to an amount based on the value of the external resistor. The input current is split between circuitry used to provide the logic signal across the selected isolation barrier and a sink transistor so that the current remains constant. This allows the digital input circuit to accurately limit input current without needing field-side power.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.