drive current for different levels of LED diming.
For this aim, a step-down LED driver
chip, XRP7613 is employed In the circuit design.
The XRP7613 is a non-synchronous step
down converter which can drive high power
LEDs at up to 1.2A of continuous current. In
order to control the LED brightness by linearly
adjusting the LED current, the PWM/EN port
of a XRP7613 chip with dividing resistance is
designed in the driver circuit as shown in Fig.
2.