Current mirror using resistor ratios in CMOS process
US5025204A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 5, 1990 |
| Grant date | Jun 18, 1991 |
| Priority date | — |
| Expiry date | Jan 5, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05F3/22
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
An operational amplifier drives the gate of a voltage controlled variation resistor having a source terminal coupled in series to a reference voltage through a current sense resistor and a drain terminal coupled in series to a supply voltage via a current regulated component, e.g., a light emitting diode. Voltage across the current sense resistor feeds back to the inverting input of the operational amplifier. The non-inverting input receives a substantially constant voltage corresponding to a target voltage, the voltage at the current sense resistor when the desired current flows therethrough. The operational amplifier varies the resistance of the variation resistor to maintain the target voltage at the current sense resistor and establish the desired current flow.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.