INA226 as short-circuit protection

Krzysztof Marcinek

Other Parts Discussed in Thread: INA226, INA209, INA300

Hi,

I'd like to use INA226 with high side shunt to measure power delivered to the external load (24V/5A). I should also add output short-circuit protection just in case.

Do you thing I can use alert pin with some logic to turn off additional p-mos switch when shunt voltage reaches the programmed limit? Lets say 10A?

As far as I know the alert pin has latch option so the processor will have time to take some action before enabling it before.

over 9 years ago

0 Edward Mullins over 9 years ago

TI__Expert 6930 points

Yes, you can use the alert pin with maybe some additional logic (perhaps some buffer) to drive the gate of the PMOS. Because the alert pin requires a conversion on the shunt voltage there will be some latentcy due to the conversion time. Ina209 has a similar function but also includes an aalog comparator for a fast response.

0 Krzysztof Marcinek over 9 years ago in reply to Edward Mullins

Prodigy 210 points

Thank you for the answer. But what about 26V limit of that IC?. The output voltage of my converter can reach 30V.

0 Edward Mullins over 9 years ago in reply to Krzysztof Marcinek

TI__Expert 6930 points

Oh, ok, I thought it was 24V... Ina226 should work. And not that I am suggesting to use this, but so you are familiar we have a new device called Ina300. It is specifically designed for over current detection. You might find it interesting if you only need to detect an overcurrent condition. If you need voltage, current and power with programmable alert, ina226 is what you will need.

0 Krzysztof Marcinek over 9 years ago in reply to Edward Mullins

Prodigy 210 points

Sorry, I wrote 24V indeed. 24V is nominal voltage, but user can adjust it in range aprox. 20-30V. Maybe I should use both INA266 for delivered power monitoring and INA300 for short-circuit cut-off. Do you think that configuration can share the shunt resistor?

0 Edward Mullins over 9 years ago in reply to Krzysztof Marcinek

TI__Expert 6930 points

Yes, you can share the shunt resistor.

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INA226 as short-circuit protection