We take the linear constant-current driver circuit based on
NU511 for example. NU511 is a single-channel, linear LED
constant-current driver chip, with up to 1.2 A driving current
and maximum 1 MHZ PWM dimming control support.
NU511 is connected in series in high-power LED lighting
circuit, the capability of wide power supply range makes
NU511 work stably in uncertain power supply applications.
When the power supply voltage is fluctuating, the chip keeps
the output current constant by adjusting the work in the linear
region of the power tube.