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Device power dissipation of TLV1117-50CDCYR

Tze Khong Yap
Prodigy 245 points
Other Parts Discussed in Thread: TLV1117

Hi,

My customer is interested to TLV1117-50CDCYR.

They would like to know the device power dissipation of this device as can't find it from datasheet.

Thank you.

Yap.

  • 0
    TI__Guru**** 165326 points

    Yap,

    The power dissipation of a linear regulator , like TLV1117, is (VIN - VOUT) * IOUT.
    In this case VOUT is 5V.

  • 0 in reply to Ron Michallick
    Prodigy 245 points

    Hi Ron,

    Thanks for the support.

    What about the specification of maximum output power for TLV1117 (SOT 223 package)?

    Assume Vin =16V, Vout=5V and Iout =0.8A

    And what about the spec of Maximum power dissipation for same package?

    Thanks,

    Yap

  • 0 in reply to Tze Khong Yap
    TI__Guru**** 165326 points

    Yap,

    The package is good at removing heat from the silicon die. Theta JB (die to bottom of heat sink tab) is 5.7C/W.

    Using your example and a perfect external heat sink (absorbs heat without changing temperature), Dissipation is (16V-5V)*0.8A= 8.8W and the die will be 8.8W*5.7C/W = 50C hotter than the heat sink. So this worst case example is supported by the TLV1117, however 99.999% of the time, a perfect heat sink won't be practical.

    A real circuit board, "PCB", needs to move the heat away from the bottom of the TLV1117 and pass the heat to the ambient air. Every other component on the circuit board also adds heat to the PCB. Therefore actual performance is very dependent on PCB performance and ambient air temperature.

    In summary, the PCB and environment (temperature and air flow) are the major contributors to limiting the max power dissipation for TLV1117 to keep die less than 150C (105C or less is best).

  • 0 in reply to Ron Michallick
    Prodigy 245 points

    Hi Ron,

    Thank you.

    Below is competitor part.

    http://www.ricoh.com/LSI/product_power/vr_ldo/r1190x/r1190x-e.pdf

    At page 4, the absolute maximum Power dissipation of SOT-89 package is only 800mA.

    Is this different concept with your explanation at above?

    Looking forward for your feedback soon.

    Thank you.

    Yap

  • 0 in reply to Tze Khong Yap
    TI__Guru**** 165326 points

    Yap,

    The data sheet has an asterisk "*" that refers to external information. However, I could not find this data in data sheet or Ricoh website.
    ∗) For Power Dissipation, please refer to PACKAGE INFORMATION.

    The power dissipation maximum has some assumptions like the TI data sheet has for the TJA parameter of 104C/W (page 5). This number comes from a JDEC standard test board. For more practical advice see the three notes below the thermal information table.

    (1) For more information about traditional and new thermal metrics, see the IC Package Thermal Metrics application report, SPRA953

    (2) For thermal estimates of this device based on PCB copper area, see the TI PCB Thermal Calculator