I am writing here because of a big problem very urgent.
We have a product pending, firmware is finished, all is finished, this is a constant current RGB driver.
I used LM3414_HV chip. There are two resistors for each LM3414HV, both are connected to one terminal of Iadj, one resistor has the other terminal connected to ground, the other has it connected to a Digital to Analog Converter to change the current.
The problem is that we assembled two prototypes and the red channel has a lower value of current: one prototype has 110mA, the other 280mA. On both prototypes current value are 420mA.
Can you help me to detect the cause? Is it possible there is a mistake in both pieces on the same channel?
Below here the PCB layout, the channel from top to down are red, green and blue. Is the PCB wrong? I followed the same layout for all three channels looking AN2076 application note.
- https://mail.sssup.it/~g.pagano/LM3414_PCB_layout.png
Thank you for your support.
Regards,
Gianluca
