Q: TLV1117: Thermal information by 1098475

Hi,

my customer has heating problems with the TLV1117. The heat dissipation is higher than expected. The ldo switches off because of overtemperature (probably). The customer has used an active load. Maybe this causes the problem but Siemens will verify that.

Following test conditions:

Ta=75C, Uin=5V, Uout=3.3V

Switching off current for the DCY package: 375mA

Switching off current for the KVU package: 207mA

But there are also questions about the thermal informations. On page 5 of the datasheet you can find different values for the thermal resistance. For DCY=104.3 (Rthja), for the KVU=50.9. But there are also values for the RthjB (5.7 for DCY and 34.8 for the KVU).

What is the test requirements (e.g. 2s2p or 1s1p)? How did we get this values? I've also checked the appnote (spra593) but what is the intersting value (Rthja, RthjB) for me?

I couldn't also find informations about the overtemperature conditions of this IC.

Thanks a lot, Xaver 


A: Re: TLV1117: Thermal information by 10449

Thermal resistances were simulated using a JEDEC standard High-K board as specified in JESD51-7 in an environment described in JESD51-2a.


Q: Re: TLV1117: Thermal information by 1098475

Hi,

we've checked the appnotes but it was not clear how the calculation for the thermal resistance of the TLV1117 is. Do we have this calculation?

Thanks a lot!

Regards, Xaver


Q: Re: TLV1117: Thermal information by 1754684

hi

have a look at SPRA953A and SLUA566 in TI literature library.

Vincenzo