Application Note : DCDC Converters (Switching Regulators)
The LED brightness is set by the current through the LEDs, it can be controlled by the Duty of a PWM signal applied to the CE pin.
The current through the LEDs can be calculated by the following formula.
ILED = Hduty × VFB / R1
Following product with high-speed dimming control can be used in the PWM signal range between 200 Hz to 300 kHz.
When controlling the LED brightness with a PWM signal of 20 kHz or less; The variation of the inductor current might cause audible sounds, please use a PWM signal in the high frequency area to avoid this.