Title:
SINGLE-SEGMENT, LINEAR AND CONSTANT-POWER LED DRIVING CIRCUIT AND METHOD
Document Type and Number:
WIPO Patent Application WO/2017/219648
Kind Code:
A1
Abstract:
A single-segment, linear and constant-power LED driving circuit (1) and method. The circuit comprises: a voltage input module (11); an LED load (12); a power switch tube (M); a sampling resistor (Rcs); an overvoltage control module (15) for detecting the voltage of a drain terminal of the power switch tube; a current control module (13) for limiting peak current of the LED load; and a comparison module (14). When an input voltage is greater than a turn-on voltage of the LED load, the current control module limits the peak current, so that current averages in different input voltage periods are constant; when the input voltage is greater than a set value, the current flowing through the LED load is turned off, thereby reducing power consumption. When the input voltage is less than the turn-on voltage of the LED load, the LED load is turned off. A compensation capacitor (Ccomp) controls average current in an alternating current period and limits the peak current, thereby implementing constant power output within a wide input voltage range. An external resistor adjusts the turn-off voltage and turn-off slope of an LED, thereby achieving high efficiency of a system and optimizing the electromagnetic interference performance of the system.
Inventors:
LIU JUN (CN)
WU QUANQING (CN)
LI GUOCHENG (CN)
WU QUANQING (CN)
LI GUOCHENG (CN)
Application Number:
PCT/CN2016/113736
Publication Date:
December 28, 2017
Filing Date:
December 30, 2016
Export Citation:
Assignee:
CHINA RESOURCES POWTECH (SHANGHAI) CO LTD (CN)
International Classes:
H05B37/02; H05B44/00
Foreign References:
| US20150137688A1 | 2015-05-21 | |||
| CN203399353U | 2014-01-15 | |||
| CN202679701U | 2013-01-16 |
Attorney, Agent or Firm:
J.Z.M.C. PATENT AND TRADEMARK LAW OFFICE (CN)
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