An Efficient Buck/Buck-Boost Reconfigurable LED Driver Employing SIN2 Reference

作者：Cho Kunhee^*; Gharpurey Ranjit

来源：IEEE Journal of Solid-State Circuits, 2017, 52(10): 2758-2768.

DOI：10.1109/JSSC.2017.2732734

• Buck-boost converter
• buck converter
• LED
• LED driver
• power factor correction (PFC)
• pulse frequency modulation (PFM)
• pulse-width modulation (PWM)
• total harmonic distortion (THD)

An efficient buck/buck-boost reconfigurable LED driver based on peak current control is introduced. The driver supports pulse-width modulation (PWM) and pulse-frequency modulation (PFM) operations. The use of a combination of rectified sin and sin(2) functions in the reference is introduced for the purpose of improving the power factor (PF) and total harmonic distortion (THD) of buck and buck-boost converters. The optimal reference waveform shape for buck and buck/boost modes can be set externally. The design ensures that the peak of the inductor current maintains a constant level that is invariant for different ac line voltages. The LED driver has been implemented in a 130-nm CMOS process. PF and THD are improved when the proposed reference is employed, and the peak PF and lowest THD values are 0.995/0.983/0.996 and 7.8/6.2/3.5% for the buck (PWM), buck (PFM), and buckboost (PFM) cases, respectively. The corresponding peak efficiency for the three cases is 88/92/91%, respectively.

• 出版日期2017-10