TPS3808: VSENSE and VDD supply sequence

Shifali N

Expert 2040 points

Part Number: TPS3808
Other Parts Discussed in Thread: TPS3840,

Hi,

Is it okay if VSENSE is applied before VDD. Since i want to monitor main supply volatge of 1.2V that will be applied to VSENSE before VDD.

Also i want to monitor VDD. Hence which is the corrct part to be selected

over 3 years ago

0 Abhinav.Sharma over 3 years ago

TI__Genius 9375 points

Hi Shifali,

You can monitor SENSE before VDD, it will come up as soon as the RESET is available. Additionally, TPS3840 is the device you should use for VDD monitoring.

Thanks,
Abhinav.

0 Shifali N over 3 years ago in reply to Abhinav.Sharma

Expert 2040 points

Hi Abhinav,

Why cant i use TPS3808. I want to use this part TPS3808G12 this volatge i want to use has minimum of 1.14. Please confirm

0 Shifali N over 3 years ago in reply to Shifali N

Expert 2040 points

Hi Abhinav,

I need to monitor VDD=1.2V. Hence the part suggested by you is not acceptable. Please suggest an alternate part

0 Abhinav.Sharma over 3 years ago in reply to Shifali N

TI__Genius 9375 points

Hi Shifali,

You can use the TPS3808 and tie SENSE to VDD, I was just assuming by your question that you did not want to use a sense pin. The TPS3808 should work fine.

Thanks,
Abhinav.

0 Shifali N over 3 years ago in reply to Abhinav.Sharma

Expert 2040 points

Hi Abhinav,

If i apply Sense voltage before VDD, what will be the state of Reset till VDD is applied.

0 Abhinav.Sharma over 3 years ago in reply to Shifali N

TI__Genius 9375 points

Hi Shifali,

RESET will be low until VDD is properly asserted and startup time is passed.

Thanks,
Abhinav.

0 Shifali N over 3 years ago in reply to Abhinav.Sharma

Expert 2040 points

Hi,

By reset is low do you mean that reset will be asserted?

0 Abhinav.Sharma over 3 years ago in reply to Shifali N

TI__Genius 9375 points

Shifali,

Yes, reset will be asserted. It will be logic low when asserted for an active-low device.

Thanks,

Abhinav.

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TPS3808: VSENSE and VDD supply sequence