Combination led driver
AssigneeAvago Technologies ECBU IP (Singapore) Pte. Ltd.
InventorsPoh Weng Yem, Keng Yeam Chang, Lee Ling Teh
Life of this patent
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Abstract
A driver circuit for a Light Emitting Diode (LED) is disclosed. The driver circuit is capable of supporting a constant LED current circuit configuration as well as an external resistor-controlled LED current circuit configuration. By integrating both configurations into a single driver circuit, the either circuit configuration can be selected without requiring a different driver circuit.
Claims20
A circuit arrangement for controlling current flowing through an LED, the circuit arrangement comprising:
- a transistor comprising first, second, and third terminals, the first terminal of the transistor being configured to be electrically connected to the LED;
- and
- a transistor input circuit configured to receive a control signal and being connected to the second terminal of the transistor, the transistor input circuit comprising first circuitry configured to control current flowing through an LED via the transistor with or without a resistor connected in series with the LED, second circuitry configured to control current flowing through an LED via the transistor only with a resistor connected in series with the LED, and at least one switch configured to control whether the first circuitry or second circuitry carries the control signal to the second terminal of the transistor.
An Integrated Circuit comprising a transistor input circuit enabling the Integrated Circuit to drive a first LED circuit arrangement when the transistor input circuit is in a first operational state as well as drive a second LED circuit arrangement when the transistor input circuit is in a second operational state, wherein the first LED circuit arrangement comprises an LED without an external resistance connected in series therewith, and wherein the second LED circuit arrangement comprises an LED with an external resistance connected in series therewith.
A transistor input circuit connected to a transistor, the transistor input circuit configured to control current flowing through a diode via the transistor, the transistor input circuit comprising:
- first circuitry configured to control current flowing through the diode with or without a resistor connected in series with the diode;
- second circuitry configured to control current flowing through the diode only with a resistor connected in series with the diode;
- and
- a switch configured to control whether the first circuitry or second circuitry is electrically connected to the transistor.
Dependencies are inferred from the claim text.