INA301-Q1: Alert pin trigger delay

Jonathan Navor

Part Number: INA301-Q1
Other Parts Discussed in Thread: INA301, INA302

Hi Team,

Good day! Kindly help us here with the customer's concern.

Customer uses INA301 for efuse application. But it responses too fast to overcurrent, the alert pin trigger immediately at power on due to inrush current, is there any way to delay the response?

I am wondering if we can add a capacitor in OUT pin to delay the response, but we don't know the maximum current OUT pin can source, and the maximum capacitance and also if some input filter could help?

I'm checking with this INA302 datasheet 7.3.3 Alert chapter the delay formula if this also applies with INA301?

Thank you in advance for the support.

Best regards,

Jonathan

over 3 years ago

0 Joseph Scherphorn over 3 years ago

TI__Expert 4680 points

Hello Jonathan,

Thanks for the question. There are a couple of avenues to consider here. For filtering on input some gain loss and input offset error will be introduced. It will be important to keep filter resistor values low and aim for short and even traces to limit uneven stray capacitance. I would note that the typical application schematic referenced in data sheet has 100n capacitor tied to ground on alert pull up; cap on input should also likely fall in this realm.
You could also look at powering up device after startup, bringing up supply pin only after load settles. Coding a blank on comparator input from alert pin for length of load settling time might also be an option.

7.4 of data sheet looks at input filtering consideration with later part discussing means of dealing with transients beyond common mode range:

INA301 36-V, High-Speed, Zero-Drift, Voltage-Output, Current-Shunt Monitor with High-Speed, Overcurrent Comparator datasheet (Rev. A) (ti.com)

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INA301-Q1: Alert pin trigger delay