Problem with ADL 5535

[obinobi]

Hi
I build a simple PCB with based on RF amplifier ADL5535 very similar to eval board from Analog Devices. But I have following problem. After some short time - less than 1 or 2 minutes I observe rapidly increasing output current from DC power supply and it looks that output is almost shorted to GND (resistance between output and GND is about 4 Ohms). I am wondering what is the root cause of the problem. I made one bug because coils blocking RF signal on DC track in the output has too small current capability 0,15 A of max. current. Could this be a problem. The amplifier is not hot before fail.

Best regards

 

[tony_lth]

That shouldn't be the coil problem, because ADL5535 has only about 100mA.

Maybe your PCB shorted to GND somewhere, or the PAD GND don't have enough grounded.

 

[vfone]

If you observe rapidly increasing output current after a while, most probably the circuit is damaged and need to be replaced.

 

[obinobi]

Hi
Thank you for yours responses. I have replaced an amplifier and after soldering I measured resistance between output and GND and it's 16 Ohm. So I am worry that IC is damaged during soldering - ESD or too high temperature. After connecting to the power supply current protection shows overload .

Best regards