TPS3700: OV detection accuracy

Patrick Zeng

Part Number: TPS3700
Other Parts Discussed in Thread: TMS320F28062, TPS3702

Hi Team,

My customer want to use TPS3700 for a OV&UV monitor for 3.3V power supply to MCU (TMS320F28062) due to functional safety requirement.

But we had a major concern on the accuracy issue. Let's take OV for example, TMS320F28062 maximum operating voltage is 3.63V, so we need to shut down the power supply if it reaches 3.63V. And the power supply nominal 3.3V is coming from a LDO : LM1117I, which is at worst 3.432V. Consider we use 1% res to set the window, and 1% accuracy for TPS3700 over full temp. The headroom for the reliable detection is not quite enough. I wonder what is the solution here?

The application &spec should be very common in functional safety required application, right? So am I looking it the wrong direction? Thanks.

Regards,

Patrick

over 4 years ago

0 Trailokya Rai over 4 years ago

TI__Genius 10951 points

Hi Patrick

For high accuracy requirement please use TPS3703 Q1. It is available for Monitoring voltage = 3.3V with window size = 4% and 7%. For 7% variant , Window size will be (3.531 , 3.069)V. UV and OV accuracy is 0.7% max and external resistor is not required.

Regards

Trailokya

0 Patrick Zeng over 4 years ago in reply to Trailokya Rai

TI__Intellectual 1090 points

Hi Trailokya,

Thanks for the reply. But I don't think TPS3703Q1 is a good option since this is a Q-version and WSON package. My customer is doing IND- Appliances product and can not accept WSON package.

Any other option to meet the requirement? What about TPS3702?

Thanks.

Regards,

Patrick

0 Trailokya Rai over 4 years ago in reply to Patrick Zeng

TI__Genius 10951 points

Hi Patrick

TPS3702 will be a good choice. It has >1% accuracy and window size is (3.0 , 3.60)V.

Regards

Trailokya

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TPS3700: OV detection accuracy