›› 2012, Vol. 25 ›› Issue (1): 1-.

• Articles •     Next Articles

A Current Sensing Circuit for High-power LED Driver Using Hysteresis Current Control

 SUN Zheng-Min, CHEN Hou-Peng, WANG Qian, LUO Sheng-Qin, SONG Zhi-Tang   

  1. (1.School of Electronics and Information Engineering,Tongji University,Shanghai 201804,China;
    2.State Key Lab of Information Function Material,Shanghai Institute of Microsystem and Information Technology,Chinese Academy of Sciences,Shanghai 200050,China)
  • Online:2012-01-15 Published:2012-01-10

Abstract:

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 sampling 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.

Key words: current control;high voltage process;matched current source;voltage compensation

CLC Number: 

  • TN432