Hi Sirs,
As title, what is the INA231's delay time from POL event to ALERT# asserted? SOL and POL who is faster if we want to achieve 500us response time?
Thank you and Best regards,
Wayne Chen
05/15/2019
Hey Wayne,
The Alert is asserted when the measurement of concern is greater than the programmed alert threshold. This measurement of concern can be shunt voltage, bus voltage, or power, and it is compared to the Alert level after every conversion time even when there is averaging and the measurement registers had not been updated yet. A SOL (shunt over-voltage limit) event will always be faster compared to a POL (power over limit) event. This is because a POL event requires measuring the shunt and bus voltages, each will require its own conversion time.
Once the real shunt voltage or system power exceeds a threshold, it will take a maximum of 2 conversion cycles before the Alert pin is asserted. So regardless of the number of averages and assuming a shunt and bus continuous mode, the alert response times become:
Max SOL alert response time = 2*t_conv_shunt + t_conv_bus
Max POL alert response time = 2*(t_conv_shunt + t_conv_bus)
This behavior is explained with Figure 21 and text from section 8.3.1.2 in the datasheet:
Hope this helps
Peter
