Other Parts Discussed in Thread: INA228
Hello,
We are using INA236 in our design. I have two questions about the response time of ALERT signal.
Question #1
According to section "8.2.3 Application Curves", when fault conditions are just exceeding the limit threshold, the response time for the ALERT can vary from one to two conversion cycles.
In our design, we set the over current limit at 7A through SOL, conversion time of VSHCT and VBUSCT are both 140us. I used 10A load current (pulse width is around 1s) to test the response time of ALERT. I found the response time ranges from 108us to 380us as shown in the graph below. It is understandable that the shortest time is less than 140us because 10A is much higher than the 7A limit threshold. However, I expect the longest response time should be no more than 280us. Is there any factor which can lead to a response time longer than twice of the conversion time?
Question #2
Also according to section "8.2.3 Application Curves" in the datasheet, the ALERT can respond in less than one conversion cycle when fault events greatly exceed the limit threshold. How do I understand this statement and how can I estimate a response time when the fault event value is much higher than the threshold.
Still use the above example, the over current limit is set at 7A, conversion time of VSHCT is set at 140us. If the real load current is 14A (twice of 7A limit), do I expect ALERT response time from 70us (50% of conversion time) to 140us (100% of conversion time)? If the real load current is 28A (four times of 7A limit), do I expect ALERT response time from 35us (25% of conversion time) to 70us (50% of conversion time)?
Can I find relevant information from the datasheet or other technical document such as user manual/application note?
Thank you!
