ADP197 Inrush Current and Absolute Maximum Ratings

Question

Hi, 
 I'm experimenting with the ADP197 evaluation board. I have two questions, please let me know. 
 
 1. 
 I am experimenting with the following circuit and measurement method. 
 Measurement procedure order (1) Turn on the 2.2A electronic load in ②. (2) Turn on 1.8V from the power supply of ① (3) Get the waveforms of Vin, Vout, Iin, and Iout at this time 
 Chattering occurs at 1.8V, which is the very limit of the input rating. Is this normal? Or do you have any suggestions for improvement?

2. 
 I did the same experiment (2.2A with electronic load) with Vin at 2.8V. Then, the inrush current became about 7A, and the IC was damaged. 
 Regarding the current, there is a description of &plusmn;4A in continuous operation, Are there any peak absolute maximum ratings? 
 If you know the characteristics of the built-in FET, please let me know. 
 
 Best Regards, 
 Naohisa

JayBee · Accepted Answer

Nachisa, 
 
 Question 1 
 
 The ADP187 has an under-voltage circuit on the Vin pin. The rising threshold is around 1.8V and the falling threshold is around 1.56V. If the load causes the input voltage to fall below the under-voltage threshold the ADP197 will turn off. The input voltage will rise and the ADP197 will turn back on. This will result in the oscillation that you have observed. 
 
 Question 2 
 
 This may be an interaction with the electronic load. Try operating the load in the constant resistance mode or try a resistive load. 
 
 Regards, 
 
 JayBee)

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ADP197 Inrush Current and Absolute Maximum Ratings