pwm control of a high power led driver (zxld1350)

Forum 2005-2010 (read only) General Frequently-Asked Questions
1

Hello,

does anybody have any experience with the ZXLD1350 from Zetex (http://www.zetex.com/3.0/pdf/ZXLD1350.pdf).
I want to control a high power led with this driver and i have connected the ADJ pin with a 2N2222A transistor and a 1k resistor to pwm pin 9 but the led is only flickering without any dimming.

------------------------------- ADJ Pin
Pin 9 ------[1k]-------|< 2N2222A
|
|
GND

On the Arduino i am using analogWrite(pin, value) to control the led which works correctly on a standard led directly driven without a led driver.

Any ideas whats wrong?

best regards
Wotan

2

Make sure all your GNDs are connected together and put a pull up resistor (4K7) from ADJ to the supply voltage of the ZXLD1350.