LED Current Overshoot Reduction Apparatus and Method
AssigneeDiodes Incorporated
InventorsDongjie Cheng, Allan Ming-Lun Lin
Life of this patent
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Abstract
An apparatus includes a reference current generation circuit coupled between a first voltage bus and a second voltage bus, wherein the reference current generation circuit is configured to generate a predetermined reference current, a first reference current path comprising a first switch, wherein the predetermined reference current is configured to be mirrored to generate a first reference current in the first reference current path, a load current path comprising a power switch, and an overshoot reduction circuit configured to reduce an overshoot occurring at a leading-edge of a load current flowing through the power switch.
Claims20
An apparatus comprising:
- a reference current generation circuit coupled between a first voltage bus and a second voltage bus, wherein the reference current generation circuit is configured to generate a predetermined reference current;
- a first reference current path comprising a first switch, wherein the predetermined reference current is configured to be mirrored to generate a first reference current in the first reference current path;
- a load current path comprising a power switch;
- and
- an overshoot reduction circuit configured to reduce an overshoot occurring at a leading-edge of a load current flowing through the power switch.
A method comprising:
- generating a predetermined reference current using a reference current generation circuit coupled between a first voltage bus and a second voltage bus;
- mirroring the predetermined reference current to generate a first reference current in a first reference current path comprising a first switch;
- and
- configuring an overshoot reduction circuit to reduce an overshoot occurring at a leading-edge of a load current flowing through a power switch.
A system comprising:
- a PWM switch, an integrated circuit and a light emitting diode coupled in series between a power source and ground;
- and
- a system controller configured to control the PWM switch, wherein the integrated circuit comprises:
- a reference current generation circuit coupled between a first voltage bus and a second voltage bus, wherein the reference current generation circuit is configured to generate a predetermined reference current;
- a first reference current path comprising a first switch, wherein the predetermined reference current is configured to be mirrored to generate a first reference current in the first reference current path;
- a load current path comprising a power switch;
- and
- a PWM deglitch circuit configured to control the first switch so as to reduce an overshoot occurring at a leading-edge of a load current flowing through the power switch.
Dependencies are inferred from the claim text.