Circuit for driving an infrared transmitter LED with temperature compensation
US8283876B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Sep 24, 2009 |
| Grant date | Oct 9, 2012 |
| Priority date | — |
| Expiry date | Aug 7, 2030 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B45/18
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Systems and methods to achieve a circuit for driving one or more infrared transmitter LEDs with temperature compensation have been disclosed. In a preferred embodiment of the invention the circuit has been applied for a rain sensing system. The junction temperature of the LED is measured and compensated by adjusting the driver current of a voltage-to-current converter driving the LED. The LED junction temperature is measured by comparing the difference in the forward diode voltage at different current densities. This voltage difference is extracted when switching the drive currents between different constant values. The measurement results are converted to digital values, which are used by a buffered dual ladder resistive DAC structure to adjust the drive current to temperature variations.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.