Circuit Arrangement and Method for the Operation of a Circuit Arrangement
Assigneeaustriamicrosystems AG
InventorPeter Trattlder
Life of this patent
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Abstract
A circuit arrangement (1) comprises a current source (10), a comparator (50) and a control device (90). The current source (10) serves for supplying a light-emitting diode (41). The comparator (50) may be coupled to the light-emitting diode (41) at a first input (51) via a push-button (101). The comparator (50) may be fed with a reference voltage (VREF) at a second terminal (52). The control device (90) selectively puts the current source (10) into a first operational state (A) for polling a push-button position of the push-button (101) or into a second operational state (B) for emitting radiation by means of the light-emitting diode (41).
Claims16
A circuit arrangement, comprising:
- a current source for supplying at least one light-emitting diode;
- a comparator which, at a first input is adapted to be coupled to the at least one light-emitting diode via a push-button and, at a second input is adapted to be fed with a reference voltage the value of which is larger than a value of a supply voltage minus a value of a light-emitting diode voltage across the at least one light-emitting diode;
- and
- a control device which selectively puts the current source into a first operational state for polling a push-button position of the push-button or into a second operational state for emitting radiation by means of the at least one light-emitting diode.
A method for operating a circuit arrangement, comprising:
- putting a current source into a first operational state and polling a push-button position of a push-button with a comparator which is coupled to at least one light-emitting diode via the push-button in such a manner that a voltage at a first terminal of the push-button is compared with a reference voltage the value of which is larger than a value of a supply voltage minus a value of a light-emitting diode voltage across the at least one light-emitting diode;
- and
- putting the current source into a second operational state for supplying the at least one light-emitting diode and providing radiation by means of the at least one light-emitting diode.
Dependencies are inferred from the claim text.