LED driver circuit with dimming control and programming interfaces

Patent metadata

Field	Value
Publication number	US-9648678-B1
Application number	US-201514852798-A
Country	US
Kind code	B1
Filing date	Sep 14, 2015
Priority date	Sep 12, 2014
Publication date	May 9, 2017
Grant date	May 9, 2017

Abstract

An LED driver circuit is provided with a dynamic operating range. A controller for a power converter is configured to regulate the output voltage and the output current generated by the power converter based on a dimming control signal from a dimming control interface, a sensed output from the power converter, and programmed maximum output voltage and maximum output current values. The tuning interface may be coupled to the dimming control interface and provide a sequence of digital pulses corresponding to a desired maximum output voltage and/or maximum output current. The controller may modify the programmed maximum output voltage and the maximum output current values based on the predetermined sequence of digital pulses received via the tuning interface circuit.

First claim

What is claimed is:

1. An LED driver circuit permitting dynamic operation range control for powering an LED array, the LED driver comprising:
a power converter configured to generate an output voltage and an output current for driving the LED array;
a dimming interface circuit configured to generate a dimming control signal based on an input received across first and second dimming input terminals;
a tuning interface circuit configured to removably couple to the first and second dimming input terminals and to provide a programming signal associated with at least one of the output voltage and the output current;
a controller configured to regulate the output voltage and the output current generated by the power converter, based on the dimming control signal, a sensed output from the power converter, and at least one of a programmed maximum output voltage and a maximum output current value associated with the power converter, the dimming interface circuit, and the tuning interface circuit; and
a tuning interface sensing circuit, the tuning interface sensing circuit comprising
first and second capacitors coupled in series between the first dimming input terminal and a circuit ground, and
a switching element having its gate electrode coupled to a node between the first and second capacitors, wherein a tuning input voltage corresponding to a high (1) digital pulse received via the tuning interface circuit is configured to charge the second capacitor and to turn on the switching element.

2. The LED driver circuit of claim 1 , wherein the LED driver circuit further comprises a programming sensing circuit, wherein the controller is configured to modify at least one of the programmed maximum output voltage and the maximum output current values based on a predetermined sequence of digital pulses received via the tuning interface circuit at the programming sensing circuit.

3. The LED driver circuit of claim 1 , further comprising:
a programming sensing circuit configured to sense a change in state associated with the tuning interface circuit, wherein the controller is configured to modify a maximum output current or a maximum output voltage associated with the power converter responsive to the sensed change in state associated with the tuning interface circuit.

4. The LED driver circuit of claim 3 , wherein the programming sensing circuit is configured to receive an input signal from the tuning interface circuit and to generate a series signal which is conveyed to the controller for modifying at least one of the programmed maximum output current and the programmed maximum output voltage.

5. The LED driver circuit of claim 1 , wherein the dimming interface circuit comprises a dimming controller coupled to the first and second dimming input terminals and to a circuit ground, and a resistance between the first dimming input terminal and the circuit ground.

6. The LED driver of claim 1 , wherein the controller is configured to provide constant output power control associated with the power converter.

7. The LED driver of claim 1 , wherein the controller is configured to identify a target maximum output voltage based on a predetermined sequence of digital pulses received via the tuning interface circuit, and is further configured to modify the programmed maximum output current and the programmed maximum output voltage based on the identified target maximum output voltage and a programmed constant power for the power converter.

8. The LED driver of claim 1 , wherein the controller is configured to identify a target maximum output current based on a predetermined sequence of digital pulses received via the tuning interface circuit, and is further configured to modify the programmed maximum output current and the programmed maximum output voltage based on the identified target maximum output current and a programmed constant power for the power converter.

9. An LED driver circuit permitting dynamic operation range control for powering an LED array, the LED driver comprising:
a power converter configured to generate an output voltage and an output current for driving the LED array;
a dimming interface circuit configured to generate a dimming control signal based on an input received across first and second dimming input terminals;
a tuning interface circuit configured to removably couple to the first and second dimming input terminals and to provide a programming signal associated with at least one of the output voltage and the output current;
a controller configured to regulate the output voltage and the output current generated by the power converter, based on the dimming control signal, a sensed output from the power converter, and at least one of a programmed maximum output voltage and a maximum output current value associated with the power converter, the dimming interface circuit, and the tuning interface circuit;
wherein the LED driver circuit further comprises a programming sensing circuit, wherein the controller is configured to modify at least one of the programmed maximum output voltage and the maximum output current values based on a predetermined sequence of digital pulses received via the tuning interface circuit at the programming sensing circuit; and
a tuning confirmation circuit coupled to the first dimming input terminal and configured to short the first dimming input terminal to circuit ground in response to a predetermined sequence of digital pulses received from the controller and corresponding to the predetermined sequence of digital pulses received by the controller from the programming sensing circuit.

10. A method of permitting dynamic operation range control for an LED driver circuit comprising a power converter configured to generate an output voltage and an output current, a dimming interface circuit having first and second input terminals, and a controller configured to regulate operation of the power converter based on a dimming control signal, a sensed output from the power converter, and at least one of a programmed maximum output voltage and a programmed maximum output current value associated with the power converter, dimming interface circuit, a tuning interface circuit, and the controller, the method comprising:
coupling the tuning interface circuit across the first and second input terminals of the dimming interface circuit;
generating a predetermined sequence of digital pulses from the tuning interface circuit, the sequence of digital pulses corresponding to at least one of a target maximum output voltage and a target maximum output current;
decoding the sequence of digital pulses to identify the target values;
modifying at least one of the programmed maximum output voltage and the programmed maximum output current values to correspond to at least one of the target maximum output voltage and the target maximum output current value; and
transmitting a responsive sequence of digital signals to a control electrode of a tuning confirmation switching element, the responsive sequence of digital signals corresponding to at least one of the modified maximum voltage output value and the modified maximum current output value.

11. The method of claim 10 , further comprising:
receiving the predetermined sequence of digital pulses from the tuning interface circuit at a programming sensing circuit of the LED driver;
transmitting the predetermined sequence of digital pulses to the controller; and
modifying at least one of the programmed maximum output voltage and the maximum output current values based on the predetermined sequence of digital pulses by the controller.

12. The method of claim 10 , further comprising comparing the responsive sequence of digita

Assignees

• Universal Lighting Tech Inc

Inventors

• Xiong Wei
• Dernovsek John J
• Goriki Takeshi

Classifications

• H05B45/10

  Controlling the intensity of the light · CPC title

• H05B33/0815 Primary

  Electricity · mapped topic

• H05B33/0845

  Electricity · mapped topic

• H05B45/39

  Circuits containing inverter bridges · CPC title

• H05B45/382

  with galvanic isolation between input and output · CPC title