A few days ago，I applyed some samples of ADL5317ACPZ-REEL7. Then I test it with the circuit come from the datasheet.At the first time,I used 71V to supply pin 4(pin VPHV). The chip was burned from pin 4. Then I tested another time today. I supplyed pin 4 from 10V.When the voltage up to 15V,the chip burned again at pin 4!