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ADUM5000 draws too much current

Question asked by Cholargos95 on Apr 17, 2018
Latest reply on Apr 18, 2018 by MSCantrell

Hi, I am building a USB isolator based on the design of the evaluation board of the ADUM4160. I also want to measure the current being drawn on the primary and the secondary side of the isolator using a microcontroller.As a current sense amplifier, I'm using the LTC6800.Everything works fine in terms of serial communication and charging of connected device.It works as it should that is like a normal USB cable.The problem is that I am measuring current on both sides that should be impossible based on the datasheet for the ADUM5000 and ADUM4160.ADUM5000 supplies a  maximum of 100mA under full load, yet I'm measuring around 200mA at 4.6V. On the primary side, it should draw a maximum of 300 or so mAmps yet I'm measuring around 530mA at 4.6V. Are current values this high normal?Schematic of the circuit is in the file under. I should also mention that the ADUM5000 gets pretty hot during operation of the isolator.

 

Thanks in advance

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