TPS3823： reset output rise time

Miranda Gu

Part Number: TPS3823

Hi team,

My customer found that the reset signal's rise time of TPS3823-33DBVR is quite long, about 1.1us, cannot meet their processor's requirement.

Their processor requires that rise time of reset signal must be less than 300ns.

Could you recommend another suitable part to meet the processor rise time requirement?

over 4 years ago

0 Ben C over 4 years ago

TI__Guru 56345 points

Hi Miranda,

Is there a reason why the processor needs a reset rise time of less than 300nS? What is the voltage being used to have a rise time of less than 300nS? I don't believe we have supervisors that has a rise time of less than 300nS.

Ben

0 Miranda Gu over 4 years ago in reply to Ben C

TI__Genius 16632 points

Hi Ben,

It's a BMC device.

Customer tried to add a 4.3kohm pull-up resistor, and reset signal rise time was decreased to ~280ns, which could meet the BMC requirement.

Do you think it's OK?

0 Ben C over 4 years ago in reply to Miranda Gu

TI__Guru 56345 points

Hi Miranda,

Please ask the customer what is their lowest VIN operating voltage.

The VOL spec is 0.4V. Therefore, to ensure that they meet this spec, you would need to use this equation:

[(VDDmin - VOL) / 1.2mA] = Rpull-up resistor (VDD = VIT - -0.2V)

Ben

0 Miranda Gu over 4 years ago in reply to Ben C

TI__Genius 16632 points

Hi Ben,

Sorry I don't get your points.

Could you please explain what is 'VIN operating voltage'? You mean TS3823 VDD? Thank you.

0 Ben C over 4 years ago in reply to Miranda Gu

TI__Guru 56345 points

Hi Miranda,

Yes, I meant VDD for TPS3823. How low can VDD go for the customer's application?

Ben

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TPS3823： reset output rise time