Multichannel constant current LED driver with high matching precision
Dejun Yu, Y. Liu, Qi Yu, Shiying Wu · 2014
Current mirror realized with resistance ratio and auto-zero technology with switch capacitor to reduce the influence of offset voltage are used to improve the matching precision. Without utilizing traditional current mirror the design simplifies the common current ratio circuit by multipliers of MOSFET in proportion. The output current matching precision of each output channel is nearly unaffected by the offset of each Operation Amplifier. The experiment results indicate that the method of multi output LED driver provides far great matching precision; it also has a simple design and has a smaller die size in layout.