Current source circuit with complementary current mirrors
US4994730A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 11, 1989 |
| Grant date | Feb 19, 1991 |
| Priority date | — |
| Expiry date | Dec 11, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05F3/262
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A current source circuit capable of generating two currents of opposite polarities. In order to generate the two currents, the circuit comprises a current source stage including a current mirror and feeding a first output current and an inverter stage connected to the source stage and generating a second output current with opposite polarity with respect to the first. The inverter stage comprises a current mirror and a variable current source defining a control electrode. In order to eliminate the differences in the amplitude of the output currents, the inverter stage comprises a memory element connected to the control electrode so as to store an electrode controlling signal. Switch elements are furthermore interposed between the first output and the second output so as to short-circuit them during the trimming step so that the two output currents are equal to one another while the memory element memorizes the control signal. This signal remains stored during the normal operation of the circuit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.