Part Number: TMS320F28377D-EP
The datasheet has the table below, but when considering a two-resistor model, which thermal resistance should be applied?
RJC and RJB ?
PsiJT and PsiJB
Hello,
Thanks for your patience during the holidays. I am providing a variety of different documentation below to help direct you here.
TI provides this app note to describe the various IC thermal parameters: Semiconductor and IC Package Thermal Metrics (Rev. D)
There is also this document: How to Evaluate Junction Temperature Properly with Thermal Metrics (Rev. B)
There are also two additional app notes that talk specifically about nFBGA Packaging and Thermal Model Analysis for TI DSPs and MCUs.
nFBGA Packaging - https://www.ti.com/lit/an/spraa99c/spraa99c.pdf
Thermal Design Guide for DSP and ARM Application Processors - https://www.ti.com/lit/an/sprabi3b/sprabi3b.pdf
Please review the SPRABI3B document which clearly describes why TI provides the Delphi thermal model parameters versus the less robust 2R model for the more complex IC's. Section 10 of the document provides a complete analysis using the provided parameters.
Best Regards,
Zackary Fleenor
Hello,
Yes, 'case' is equivalent to 'package top'.
RΘJC: Junction-to-case thermal resistance - this is a true thermal resistance value
PsiJT: Junction-to-package top - this is an estimated thermal metric, see the description below
RΘJB: Junction-to-board thermal resistance
PsiJB: Junction-to-board
These parameters are detailed in the Semiconductor and IC Package Thermal Metrics (Rev. D) document.
Best Regards,
Zackary Fleenor
Thank you for your detailed answer.
I understand that these are true thermal resistance values and estimated thermal metric values.
RΘJB (7.9 deg/W) and PsiJB (6.1 deg/W [No Air]) are similar values, but I don't understand why RΘJC (10.2 deg/W) and PsiJT (0.11 deg/W [No Air]) are about 100 times different. Please explain.
