Hi,
I am trying to use the TPS61500 IC to drive a single 30W led. The led forward voltage is about 12 -13 V and i wish to have maximum possible (>2A) led current. I have built the circuit of TPS61500EVM-369 from the user guide in the pure PWM configuration. However with a supply voltage is 12.6V i can only get 1.5A led current. my OVP resistors are 10k to 180k, i have tried using 51k and 180k for freq control, I have tried 4.7uH,10uH and 15uH 4A sat current inductors and i have tried to chnage the output capacitor value between 1uF and 10uF to no avail. I have changed the sense resistor between 0.1Ohm and 0.05Ohm but the current doesnt seems to change.
Also i seem to have flickering issues at some dimming levels.
I use the recommended Q1 fet but for the Q2 i am using IRFR9024N due to a lack of parts, can this be responsible for flickering? Also admittedly my layout design is quite poor (as shown below ).
Thank you all in advance and best regards.
Batur