Driver circuit and method for operating a light emitting unit
AssigneeRenesas Design (UK) Limited
InventorsThomas JACKUM, Saska LINDFORS
Life of this patent
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Abstract
A driver circuit for providing a driver current for operating a light emitting unit at a brightness level corresponding to a value of a brightness code. The driver circuit includes a digital-to-analog converter, DAC, stage configured to generate an intermediate signal in dependence of the value of the brightness code. Furthermore, the driver circuit includes a gain stage configured to amplify the intermediate signal in dependence of the value of the brightness code to provide the driver current.
Claims15
A driver circuit for providing a driver current for operating a light emitting unit at a brightness level corresponding to a value of a brightness code;
- wherein the driver circuit comprises:
- a digital-to-analog converter (DAC), stage configured to generate an intermediate signal in dependence of the value of the brightness code, wherein a level of the intermediate signal depends on a digital input value being inputted to the DAC stage, wherein the DAC stage is configured to convert the digital input value into an analog value representing a current using a linear mapping between the digital input value and the level of the intermediate level;
- and
- a gain stage configured to amplify the intermediate signal in dependence of the value of the brightness code to provide the driver current for approximation of a target relationship between the brightness code and the driver current.
A method for providing a driver current for operating a light emitting unit at a brightness level corresponding to a value of a brightness code;
- wherein the method comprises:
- generating an intermediate signal in dependence of the value of the brightness code using a digital-to-analog converter (DAC), stage, wherein a level of the intermediate signal depends on a digital input value being inputted to the DAC stage, wherein the DAC stage is configured to convert the digital input value into an analog value representing a current using a linear mapping between the digital input value and the level of the intermediate level;
- and
- amplifying the intermediate signal in dependence of the value of the brightness code, using a gain stage, to provide the driver current for approximation of a target relationship between the brightness code and the driver current.
Dependencies are inferred from the claim text.