Multi-channel dual-mode digital control LED driving circuit and LED lamp

Patent metadata

Field	Value
Publication number	US-10143072-B2
Application number	US-201615507385-A
Country	US
Kind code	B2
Filing date	Feb 1, 2016
Priority date	May 19, 2015
Publication date	Nov 27, 2018
Grant date	Nov 27, 2018

Abstract

A multi-channel dual-mode digital control LED driving circuit and an LED lamp. The driving circuit comprises a current sampling module ( 10 ), a comparison and detection module ( 30 ), a digital control module ( 40 ) and a constant current control module ( 20 ). By means of feeding back an adjustment current for the load ( 70 ) by the digital control module ( 40 ), and feeding back and adjusting a current of the load ( 70 ) in real time by the constant current control module ( 20 ), the driving circuit adjusts the load ( 70 ) in real time, so that dual-mode cooperation working is realized, and thus a response speed is greatly improved, the accuracy of an output voltage and the current of the load ( 70 ) is improved, and at the same time, the system stability is enhanced and wide universality is achieved.

First claim

What is claimed is:

1. A multi-channel dual-mode digital control light emitting diode (LED) driving circuit comprising: a current sampling module, a comparison and detection module, a digital control module and a constant current control module;
the current sampling module converts a current signal of a load into a sampling voltage signal, before outputting to the comparison and detection module and the constant current control module; the comparison and detection module compares the sampling voltage to a fixed voltage, before generating a high/low voltage signal according to a comparison result, and outputting to the digital control module, while at a same time, a dynamically changing voltage signal is generated and output to the constant current control module; the digital control module outputs a corresponding step-up or step-down output signal to an external voltage boost control module and a drive module sequentially, according to the high/low voltage signal output from the comparison and detection module, thus a feedback adjustment to the load is achieved; the constant current control module compares to a fixed frequency sawtooth signal according to the sampling voltage, and generates a switching signal with a changing duty cycle in a real time, before controlling a switch state of an inner constant current drive tube according to the duty cycle change of the switching signal, followed by feeding back an adjustment current for the load in a real time.

2. The multi-channel dual-mode digital control LED driving circuit according to claim 1 , wherein, the comparison and detection module comprises:
a detection unit, applied to comparing and amplifying the sampling voltage with the fixed voltage, before outputting an amplifying signal to a comparison unit, the larger a ratio between the fixed voltage and the sampling voltage is, the higher a voltage of the output amplifying signal is;
a comparison unit, applied to outputting a low voltage from a first output end and a high voltage from a second output end, when the amplifying signal output from the detection unit is larger than a first threshold voltage, and outputting a high voltage from the first output end and a low voltage from the second output end, when the amplifying signal output from the detection unit is smaller than a second threshold voltage, as well as outputting a low voltage from both the first and second output ends, when the amplifying signal output from the detection unit is larger than the second threshold voltage but smaller than the first threshold voltage;
an input end of the detection unit connects to the output end of the current sampling module, the detection unit connects to the comparison unit, while the first and second output ends of the comparison unit connect to the digital control module.

3. The multi-channel dual-mode digital control LED driving circuit according to claim 2 , wherein, the digital control module comprises:
a logic unit, applied to converting the signals from both output ends of the comparison unit into an eight-bit logic control signal, when the first output end of the comparison unit is outputting the low voltage, and the second output end is outputting the high voltage, the eight-bit logic control signal rises bit by bit from low to high in a 256-bit interval; when the first output end of the comparison unit is outputting the high voltage, and the second output end is outputting the low voltage, the eight-bit logic control signal reduces bit by bit from high to low in the 256-bit interval; when the first output end and the second output end of the comparison unit are both outputting the low voltage, the eight-bit logic control signal keeps unchanged;
a voltage control unit, applied to stepping down the output voltage a stepped voltage, when the eight-bit logic control signal is raised one bit, and stepping up the output voltage a stepped voltage, when the eight-bit logic control signal is lowered one bit;
a first input end of the logic unit connects to the first output end of the comparison unit, a second input end of the logic unit connects to the second output end of the comparison unit, the logic unit connects to the external voltage boost control module through the voltage control unit.

4. The multi-channel dual-mode digital control LED driving circuit according to claim 3 , wherein, the voltage control unit comprises eight current switch subunits controlled by the eight bit logic control signal, including: a first current switch subunit, a second current switch subunit, a third current switch subunit, a fourth current switch subunit, a fifth current switch subunit, a sixth current switch subunit, a seventh current switch subunit, an eighth current switch subunit, and a resistors array connected according to a binary rule, together with a mirror current subunit;
the resistors array comprises fifteen resistors strings, including: a first resistors string, a second resistors string, a third resistors string, a fourth resistors string, a fifth resistors string, a sixth resistors string, a seventh resistors string, an eighth resistors string, a ninth resistors string, a tenth resistors string, an eleventh resistors string, a twelfth resistors string, a thirteenth resistors string, a fourteenth resistors string and a fifteenth resistors string;
the current switch subunits, applied to outputting a first mirror current to the resistors array, according to a corresponding logic control signal in the eight-bit logic control signal;
the mirror current subunit, applied to outputting a second mirror current to the resistors array;
an external power supplier end connects to one end of the first resistors string and one end of the ninth resistors string, through the first current switch subunit, while another end of the first resistors string gets grounded; the external power supplier end connects to another end of the ninth resistors string, one end of the second resistors string and one end of the tenth resistors string, through the second current switch subunit, while another end of the second resistors string gets grounded; the external power supplier end connects to another end of the tenth resistors string, one end of the third resistors string and one end of the eleventh resistors string, through the third current switch subunit, while another end of the third resistors string gets grounded; the external power supplier end connects to another end of the eleventh resistors string, one end of the fourth resistors string and one end of the twelfth resistors string through the fourth current switch subunit, while another end of the fourth resistors string gets grounded; the external power supplier end connects to another end of the twelfth resistors string, one end of the fifth resistors string and one end of the thirteenth resistors string, through the fifth current switch subunit, while another end of the fifth resistors string gets grounded; the external power supplier end connects to another end of the thirteenth resistors string, one end of the sixth resistors string and one end of the fourteenth resistors string, through the sixth current switch subunit, while another end of the sixth resistors string gets grounded; the external power supplier end connects to another end of the fourteenth resistors string, one end of the seventh resistors string and one end of the fifteenth resistors string, through the seventh current switch subunit, while another end of the seventh resistors string gets grounded; the external power supplier end connects to another end of the fifteenth resistors string and one end of the eighth resistors string, through the eighth current switch subunit and the mirror current subunit, while another end of the eighth resistors string gets grounded; one end of the eighth resistors string is the output end of the voltage control unit,

Assignees

• Shenzhen Skyworth Rgb Electronics Co Ltd
• Shenzhen Skyworth Semiconductor Design Center Co Ltd
• Shenzhen Skyworth Rgb Electronics Co Ltd

Inventors

• Sun tianqi

Classifications

• H04B7/2656

  for structure of frame, burst · CPC title

• H05B41/3927

  by pulse width modulation (H05B41/3922 takes precedence) · CPC title

• H05B45/46

  having LEDs disposed in parallel lines · CPC title

• H05B41/28

  using static converters · CPC title

• H05B41/282

  with semiconductor devices ({H05B41/2806}, H05B41/288, H05B41/295 take precedence) · CPC title