220V Quasi-Resonant Inverse Buck LED Driver, with valley skipping

Open online SPICE simulator circuit link: lighting_led_220V_inverse_buck_qr_2.tsc

220V Quasi-Resonant Inverse Buck LED Driver

LEDs

VDC IN

Inverse buck circuits are ideal for driving high brightness LEDs with high efficiency. This example drives
sixteen ~11V Lumileds LEDs at ~120mA (12% dimming level) with 220V DC input. The selected 250V
OptiMOS™ MOSFET is perfect thanks to its low cost, low gate charge and low threshold voltage which
makes it possible to drive it with a simple totem pole gate driver.
The duty cycle is chosen in such a way that this circuit operates in quasi-resonant mode. The MOSFET
is turned on in the second valley. A zero-crossing detection signal is generated for the controller
(e.g. XMC1000) by capacitive coupling.