DRV104PWPR THERMAL ANALYS

Hi John,

I use to provide Applications Engineering support for the DRV104 some years ago, and do have access to some of its archived information. Thus, when I saw this inquiry I wanted to try and provide you with what I know about a likely applicable JEDEC specification, and what I think may be the answer.

I am fairly certain that the JEDEC specification being referred to in the DRV104 datasheet is JESD51-12, "Guidelines for Reporting and Using Electronic Package Thermal Information." Section 4, "Reporting electronic package thermal results," provides Table 1 — JESD51 Thermal measurement standards by category. Regards PC boards, under the "Boards" title, there is footnote - NOTE 6. That note provides an explanation of two test board cross-sections. The first is a low effective thermal conductivity, referred to as the "1s", or 1 signal plane board. An important point about this board is this board does not have power planes. The "1s" board has a 2 oz/ft finished copper thickness. The second board is a high effective thermal conductivity cross-section referred to as a 2s2p, which has two signal planes and two power planes. 

If you would like to view JESD52-12, it is available online:

www.jedec.org/.../jesd51-12.pdf

Most of the DRV104 development team is no longer with TI, but there are a few people here who had some involvement with it. The two that I did speak with remembered the thermal characterization using a simple board having a single plane. That tends to indicate that the "1s" cross-section board was used. There was even a small even EVM developed for the DRV104.  When I examine one, I find that it uses a single signal layer and has no power planes. It appears to be modeled after the "1s" board. That EVM board uses 1 oz copper, not the 2 oz copper called for in the JEDEC. 

I hope this helps answer your question.

Regards, Thomas

PA - Linear Applications Engineering