Today I received chinese ADAU1452 board. When powered it with USB port of the laptop, I can see that the leds are blinking and board seems to be working. After few minutes I found out that the transistor marked as IC4 becomes burning hot! Is this happened to anyone? Is this normal?
Since the part is designated IC4 rather than Q4, chances are it is an integrated circuit, rather than a discrete transistor. Could perhaps be a voltage regulator. Does it have any writing/markings on the top (might need a magnifying glass and or to hold it in the light at a particular angle to read it)? Do you think you could follow the traces that go to the hot device and see where they go?
The component labeled as Y2 on top.
Y2 seems like a normal transistor:
25pcs SS8550 Transistor Y2 PNP 25V 1500mA 300mW Surface Mount SOT-23 714998792426 | eBay
ADAU1452 draws current directly through this transistor according to the following circuit diagram. Do you have this heating issue? I can't even touch it... it's too hot!
Y2 seems like a normal transistor:
25pcs SS8550 Transistor Y2 PNP 25V 1500mA 300mW Surface Mount SOT-23 714998792426 | eBay
ADAU1452 draws current directly through this transistor according to the following circuit diagram. Do you have this heating issue? I can't even touch it... it's too hot!
They might have under specced that transistor by the looks of it. It needs to be at least capable of dissipating 1W. The transistor specified in the datasheet is a STD2805