Extended range current-to-time converter
US4104547A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 21, 1977 |
| Grant date | Aug 1, 1978 |
| Priority date | — |
| Expiry date | Mar 21, 1997 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B7/093
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An improved comparator circuit is employed to respond to the charge on a capacitor which represents the integrated value of an input current. When the charge exceeds the comparator trip point, an output is generated. The output is delayed in time from the onset of the input current by an amount that is almost exactly linearly proportional to the current magnitude. The improvement comprises a circuit that senses the onset of comparator conduction and supplies the current necessary to operate the comparator. At very low input current values a condition can be reached where the current drawn by the comparator input equals or exceeds the applied current. For this condition an ordinary comparator will never trip. The improved circuit prevents this and, since the current added is only to compensate, the timing function is not seriously perturbed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.