• State TI Thinks Resolved
  • Locked Locked
  • Replies 3 replies
  • Answers 1 answer
  • Subscribers 79 subscribers
  • Views 716 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

MSP430I2040: BOR and SVS behavior – Power Up

Kuerbis
Expert 4145 points

Part Number: MSP430I2040

Hi Team

 

I have few questions for BOR,

Please look the following image. I made it based on MSP430i2040 datasheet - SLAS887A and MSP430i2xx FamilyUser's Guide - SLAU335

 

  1. BORH is actually V(VCC_BOR_IT+) =1.18V. It’s very low from VCC (2.2V to 3.6V). How to grantee VCC is within Recommended Operating Conditions VCC (2.2 to 3.6V) before BOR is released?

  2. How much is the delay time from the reset from SVSL to BOR?

  3. How to behave the device if VCC doesn’t become the VCC spec at BOR is released?

 

The customer worrys that BORH and SVSL couldn’t detect VCC low voltage.

 

Thanks and Best regards,

 Kuerbis

  • 0
    TI__Expert 5490 points

    Hi Kuerbis,

    before I answer your first question, let me answer your second. Please have a look at picture below. As you can see, BOR is generated by ORing of BORH and SVSL. That means as soon as both signals are 0, BOR becomes 0. We don't specify this time, but it is very short.

    To your first and third question:

    In principle there are three cases:

    1. Voltage is below 1.7V. In this case device stays in reset as BORH is above the reset level, but SVSL is still high. The device will not run.

    2. Voltage is above 2.2V. In this case the device will start after BOR is released and it is safe to execute code.

    3. Voltage is between 1.7V and 2.2V: In this case the core voltage is safe and you can execute code. As the voltage is below the recommended operating condition for VCC, you cannot use eg. the ADC. You need to monitor the voltage with the Voltage monitor and wait until it is at a safe level.

    Best regards,

    Andre

  • 0 in reply to Andre Frantzke
    TI__Expert 4145 points

    Hi Andre,

     

    Thank you for giving to me the reply.

    I understand three cases after BOR.

     

    I would like to ask one more question.

    User's Guide says that The primary function of the brownout reset (BOR) circuit occurs when the device is powering up. It is functional very early in the power-up ramp.

     

    When BOR is active? Do you have any specific VCC voltage or timing?

     

    Thanks and Best regards,

    Kuerbis

  • 0 in reply to Kuerbis
    TI__Expert 5490 points

    Hi Kuerbis,

    please see this e2e post for more information about the BOR. Although it is not directly the MSP430I20xx devices the general concept is the same.

    Best regards,
    Andre

**Attention** This is a public forum