• State TI Thinks Resolved
  • Locked Locked
  • Replies 3 replies
  • Answers 1 answer
  • Subscribers 63 subscribers
  • Views 407 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.

LMZ31506: Device SPICE odel pins 8 & 9 (INH/UVLO) does not seem to function properly as ENABLE pins

Kevin Lai
Intellectual 2916 points
Part Number: LMZ31506
Other Parts Discussed in Thread: , TPS84621

Hi team,

customer is facing the following challenge. please advise.

I’ve pulled the SPICE model for the LMZ31506 from TI’s website to do some simulations, and I noticed that pins 8 & 9 (INH/UVLO) don’t seem to function properly as “enable” pins. According to the datasheet, tying the two pins together should allow them to function as inhibit pins. I’ve done that and tried connecting those to ground, but my output is still enabling (see image). Is there a way that I can edit the .subckt to add in the “enable” functionality?

 

thanks,

Kevin 

  • 0
    TI__Mastermind 35165 points

    Hi Kevin,

    It looks like the schematic has the AVG PSPICE model. With the average PSPICE model, the main purpose is AC simulations so most of the features are left unmodeled as they are not necessary for AC simulations. The PSPICE Transient model would have this feature modeled.

    Anthony

  • 0 in reply to Anthony F
    TI__Intellectual 2916 points

    Hi Anthony, 

    PSpice is only showing an Average model available for the LMZ31506. 

    there is a transient model for the LMZ31506H variant, but this is not exactly the same device.

    on the product page, there is no download option for the transient model. there also seems to be an unencrypted transient model for the TPS84621 in here which does not really make sense to me.

    can you please provide a .inc, .mod, or other SPICE file derivative? 

    Thanks,

    Kevin 

  • 0 in reply to Kevin Lai
    TI__Mastermind 35165 points

    The TPS84621 is the same part as the LMZ31506 so you can use the TPS84621 transient model for the LMZ31506. This is the part number the LMZ31506 was originally released as and shortly after release the LMZ31506 was released to with the rest of our family. This happened due to the timing of this parts release and the acquisition of National Semiconductor.