| Title |
Design of an Active Current Regulator for LED Driver IC |
| Authors |
윤성진(Yun, Seong-Jin) ; 오택준(Oh, Tak-Jun) ; 조아라(Jo, A-Ra) ; 기석립(Ki, Seok-Lip) ; 황인철(Hwang, In-Chul) |
| DOI |
https://doi.org/10.5370/KIEE.2012.61.4.612 |
| Keywords |
Active current regultor ; Current mirror ; LED driver IC |
| Abstract |
This paper presents an active current regulator for LED driver IC. The proposed driver circuit is consists of DC-DC converter for supplying constant DC voltage to LED, active current regulator for compensating channel-to-channel current error from LED strings and feedback circuit for controlling duty ratio of the converter. The proposed active current regulator senses current of LED channels by equalizing both V_{DS} and V_{GS} at LED current control transistor. Because the proposed circuit directly measures the LED channel current without a sensing resistor and regulates all channel with same regulation loop, the power consumption and the current error are much small compared with previous works. The measured maximum efficiency of overall LED driver IC is approximately 94% and current error of LED channel-to-channel is under pm1.3%. The proposed LED driver IC is fabricated Dongbu 0.35um BCD process. |