If you notice flicker, the PWM frequency is too low. I recently built a PWM driver for high power RGB LEDs and there's no flicker, even at very dim brightness.

If you notice flicker, the PWM frequency is too low. I recently built a PWM driver for high power RGB LEDs and there's no flicker, even at very dim brightness. I don't know what's on the market, but probably I should get into it ;)