• State TI Thinks Resolved
  • Locked Locked
  • Replies 2 replies
  • Answers 1 answer
  • Subscribers 63 subscribers
  • Views 483 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.

TPS65920 I/O Leakage Current (e.g., LEDA, LEDB, PWM0 and PWM1)

Charles McCarthy
Intellectual 500 points
Other Parts Discussed in Thread: TPS65920, OMAP3530

Hello!  Can anyone tell me what the leakage current is on the TPS65920 I/Os?  In my particular case I am interested in the leakage on the LEDA, LEDB, PWM0 and PWM1 signals but would be interested in this information for other I/Os as well.

Thanks!

Charles

  • 0
    TI__Genius 15100 points

    Hi Charles,

    The leakage on these pins is extremely low, < 10nA.

    Generally speaking leakage on other pins is also very low, its either the same as for above pins or few couple tens of nA. I am not sure why you would need these leakage currents. I dont see any reason to be concerned about leakage currents.

     

    Regards,

    Gandhar.

     

     

  • 0 in reply to Gandhar Dighe
    Intellectual 500 points

    Gandhar, thank you for the information!  In my OMAP3530 / TPS65920 design I can't use the LEDA signal as you might normally use it because it is a very low-power portable application and I don't have the option to use low-voltage White LEDs nor can I afford the power wasted using current-setting resistors (e.g., Figure 9-1 in the DM, SWCS037E).  Let me digress and explain my situation:

    I need to ensure I have exactly the same current in each White LED, meaning I either need to have (a) the LEDs in series, (b) matching constant-current sinks in the TPS65920 or (c) have a constant-current source Vsupply.  Since the TPS65920 is not a constant-current sink device I need option (a) or (c).  Then, if I go with option (a) I still have a problem with variation in the Vf LEDs from unit-to-unit and over temperature, resulting in nominal brightness variation and makng this option a bit difficult to use.  This leaves option (c).

    To implement a constant-current source Vsupply I can either use a boost (with down-regulation), buck-boost or a current regulator specific to LED applications. In the case of using boost or buck-boost regulator the TPS65920 LEDA signal could be used in the regulator feedback loop to implement dimming on the LEDs.  Now, in that scenario, if the regulator has a very low feedback voltage then I wanted to ensure that leakage through the LEDA pin was insufficient to unintentionally dim the LEDs.  based on your answer it is not a factor.

    Regards,

    Charles