LT3065 - Junction Temperature

Hello,

Is there any LT3065 product which has a junction temperature of 175°C or higher? MP- and H- grades have a junction temperature of 150°C, are these absolute maximum values? What happens when the temperature exceeds 150°C? Asking this because in my project, I have a problem with high power dissipation. My values are:

Vin_max = 29.5V, Iload = 117mA, Vout = 5V, Tambient_max = 50°C

Can I use any LT3065 product if I have such values in my project? 

Best regards,

Parents
  • 0
    •  Analog Employees 
    on Oct 11, 2021 5:08 PM

    Hello,

    in your setup the power dissipation is 2.867W!!!! With the thermal impedance (Junction-ambient) values from the datasheet of 28C/W (MSOP) resp. 31C/W (DFN) you have a deltaT of 80.2K resp. 88.8K. If ambient is 50C you end up with a junction temp of 130k or more (with optimum layout for thermal performance), otherwise more.

    H and MP grade are capable for this, but in general I would recommend a switcher for a more efficent DC/DC conversion or a different LDO with a larger package and better thermal impedance values.

    LT3081 offers TEMP pin for monitoring, larger packages and hence better thermal performance. But still getting hot for sure.

Reply
  • 0
    •  Analog Employees 
    on Oct 11, 2021 5:08 PM

    Hello,

    in your setup the power dissipation is 2.867W!!!! With the thermal impedance (Junction-ambient) values from the datasheet of 28C/W (MSOP) resp. 31C/W (DFN) you have a deltaT of 80.2K resp. 88.8K. If ambient is 50C you end up with a junction temp of 130k or more (with optimum layout for thermal performance), otherwise more.

    H and MP grade are capable for this, but in general I would recommend a switcher for a more efficent DC/DC conversion or a different LDO with a larger package and better thermal impedance values.

    LT3081 offers TEMP pin for monitoring, larger packages and hence better thermal performance. But still getting hot for sure.

Children
No Data