Single stage buck boost type LED driver
Technologies are described for a light emitting diode (LED) driver configured for powering LED(s) and having a wide input voltage range between about 100V and about 528V, high power factor, low total harmonic distortion (THD), and low output current ripple load. The LED driver has a single stage buck-boost type converter with output current regulation, an output current regulation circuit, a ripple control circuit having a transient voltage suppressor (TVS) and a parallel resonant LC filter, a power factor correction (PFC) control circuit having a digital compensation block, a PFC controller, and a gate drive IC.
1 . A light emitting diode (LED) driver having an input voltage range between 100V and 528V and configured for powering an LED load at a substantially constant current, comprising:
a single stage buck-boost type power factor correction (PFC) circuit, having a PFC controller, the buck-boost PFC circuit is configured to:
(i) draw an alternating current (AC) input current having a sinusoid waveform as line voltage;
(ii) sense a rectified input voltage from a full-wave rectifier at the PFC controller and output a direct current (DC) voltage and a DC current;
(iii) achieve a low total harmonic distortion (THD) of at most 10%;
(iv) achieve high power factor (PF) between 0.95 and 1.00;
(v) achieve a low line frequency ripple on the output DC current of at most 10%; and
(vi) control a maximum switching frequency, mitigate electromagnetic interference, and improve efficiency.
2 . The LED driver of claim 1 , wherein the single stage PFC is selected from the group consisting of buck-boost, isolated flyback, non-isolated flyback, Sepic, and Cuk.