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TPS61094: Charging Cap without Vin

Dave Pulvermacher
Intellectual 870 points
Part Number: TPS61094

When performing validation on our PCBAs we'd like to do a quick charge on the supercap before applying any other power to the board.  Will it harm the TPS61094 if we apply 1.8v-2.2v to pin 6, SUP for 5seconds?  

This is assuming VCAP is starting at or near 0v.  

  • 0
    TI__Expert 5180 points

    Hi Dave,

    Please let me check first that, do you mean VCAP start up at 1.8v-2.2v or near 0V? Based on your description, I think it is applying 1.8v-2.2v to pin 6, SUP for 5seconds and start up at this 1.8v-2.2v?

    Best Regards,

    Eric Yue

  • 0 in reply to Eric Yue
    Intellectual 870 points

    VCAP would start at 0v.  We would then apply 2.15v to pin 6 for ~5sec, fast charging the cap.  After 5sec 2.15v would be removed, and 3v would be applied to VIN and programming would commence.  

    There are 2 goals we are trying to accomplish:  1) Validate the cap actually charges  2) measure Iq

    We can't measure Iq until the cap is fully charged.  So we are fast charging to 2.15 and then allowing VIN to charge the rest of the way (with preset Ichg).  

  • 0 in reply to Dave Pulvermacher
    TI__Expert 5180 points

    Hi Dave,

    You can disable EN pin before start up, and the device will be in True shutdown mode if MODE pin is high. The applied 2.15V is pre-bias voltage for the device. When EN is enable, the chip mode will transfer from True shutdown mode to Auto buck/boost mode, starting from the pre-bias voltage.

    Best Regards,

    Eric Yue