CONTROL CIRCUIT OF LIGHT EMITTING DIODES AND OPERATION METHOD OF A CONTROL CIRCUIT OF LIGHT EMITTING DIODES

摘要

A control circuit of light emitting diodes is used for driving at least one series of light emitting diodes. The control circuit includes a current setting pin, a driving current generator, a regulator circuit, and an adjuster. A reference current flows through the current setting pin. The driving current generator is used for generating a driving current flowing through the series of light emitting diodes according to the reference current. The adjuster generates an adjustment voltage according to the reference current. Then, the regulator circuit generates a supply voltage to drive the series of light emitting diodes, and regulates a voltage of a first terminal of the series of light emitting diodes at a target voltage according to the adjustment voltage. The target voltage is increased with decrease of the driving current when the driving current is less than a first predetermined current.

主权项

1. A control circuit of light emitting diodes, wherein the control circuit is used for driving at least one series of light emitting diodes, the control circuit comprising:
a current setting pin, wherein a reference current flows through the current setting pin; a driving current generator for generating a driving current flowing through the series of light emitting diodes according to the reference current; an adjuster for generating an adjustment voltage according to the reference current; and a regulator circuit for regulating a voltage of a first terminal of the series of light emitting diodes at a target voltage and generating a supply voltage to drive the series of light emitting diodes according to the adjustment voltage; wherein when the driving current is less than a first predetermined current, the target voltage is increased with decrease of the driving current.