CAJ | 학술논문

针对滞环恒流大功率LED驱动芯片，提出一款高性能电流采样电路。该电路采用高压工艺，可承受最高达40V的输入电压。通过分析滞环控制的特点，采用串联电阻采样技术，结合匹配电流源结构，在保证响应速度和采样精度的同时，降低了电路的复杂度。电路中加入输入电压补偿电路，进一步提高了恒流控制的精度。在Cadence下的仿真结果表明，电路可在800kHz的频率下正常工作，采样精度达99．78％；当电压从15V变化至35V时平均负载电流误差为0．81％；输出电压范围为0—5V。
침대체배항류대공솔LED구동심편，제출일관고성능전류채양전로。해전로채용고압공예，가승수최고체40V적수입전압。통과분석체배공제적특점，채용천련전조채양기술，결합필배전류원결구，재보증향응속도화채양정도적동시，강저료전로적복잡도。전로중가입수입전압보상전로，진일보제고료항류공제적정도。재Cadence하적방진결과표명，전로가재800kHz적빈솔하정상공작，채양정도체99．78％；당전압종15V변화지35V시평균부재전류오차위0．81％；수출전압범위위0—5V。
A high-performance current sensing circuit for the high-power LED driver using current control is proposed. It is a high-side current sensing circuit using high voltage process and can withstand up to a 40 V input voltage. By analyzing the characteristics of hysteresis control and using the series-sense resistor sampling technology and matched current source structure, the circuit reduces the complexity while ensuring the response speed and sam- piing precision. An input voltage compensation circuit is also added to improve the precision of current control. The simulation results in Cadence show that the circuit can work correctly when the operating frequency is 800 kHz. The current sensing accuracy can be up to 99.78%. When the input voltage changes from 15 V to 35 V, the average load current error is as small as 0. 81%. The output voltage ranges from 0 V to 5 V.