S9S12XS256J0CAL Datasheet, PDF (664/738 Pages) Freescale Semiconductor, Inc – Microcontrollers

Electrical Characteristics
Table A-5. Thermal Package Characteristics (9S12XS256)¹
Num C
Rating
Symbol
Min
Typ
Max
Unit
LQFP 112
1 D Thermal resistance LQFP 112, single sided PCB²
θ_JA
—
—
62
°C/W
2 D Thermal resistance LQFP 112, double sided PCB
with 2 internal planes³
θ_JA
—
—
51
°C/W
3 D Junction to Board LQFP 112
4 D Junction to Case LQFP 112⁴
5 D Junction to Package Top LQFP 112⁵
θ_JB
—
—
39
°C/W
θ_JC
—
—
16
°C/W
Ψ_JT
—
—
3
°C/W
QFP 80
6 D Thermal resistance QFP 80, single sided PCB²
θ_JA
—
—
57
°C/W
7 D Thermal resistance QFP 80, double sided PCB
with 2 internal planes³
θ_JA
—
—
45
°C/W
8 D Junction to Board QFP 80
9 D Junction to Case QFP 80⁴
10 D Junction to Package Top QFP 80⁵
θ_JB
—
—
29
°C/W
θ_JC
—
—
20
°C/W
Ψ_JT
—
—
5
°C/W
LQFP 64
11 D Thermal resistance LQFP 64, single sided PCB²
θ_JA
—
—
68
°C/W
12 D Thermal resistance LQFP 64, double sided PCB
with 2 internal planes³
θ_JA
—
—
50
°C/W
13 D Junction to Board LQFP 64
θ_JB
—
—
32
°C/W
14 D Junction to Case LQFP 64⁴
θ_JC
—
—
15
°C/W
15 D Junction to Package Top LQFP 64⁵
Ψ_JT
—
—
3
°C/W
1 ^{The values for thermal resistance are achieved by package simulations}
2 ^{Junction to ambient thermal resistance, θ}JA ^{was simulated to be equivalent to the JEDEC specification JESD51-2 in a}
horizontal configuration in natural convection.
3 ^{Junction to ambient thermal resistance, θ}JA ^{was simulated to be equivalent to the JEDEC specification JESD51-7 in a}
horizontal configuration in natural convection.
4 ^{Junction to case thermal resistance was simulated to be equivalent to the measured values using the cold plate technique with}
the cold plate temperature used as the “case” temperature. This basic cold plate measurement technique is described by MIL-
STD 883D, Method 1012.1. This is the correct thermal metric to use to calculate thermal performance when the package is
being used with a heat sink.
5 ^{Thermal characterization parameter Ψ}JT ^{is the “resistance” from junction to reference point thermocouple on top center of the}
case as defined in JESD51-2. Ψ_JT is a useful value to use to estimate junction temperature in a steady state customer
enviroment.
S12XS Family Reference Manual, Rev. 1.13
664
Freescale Semiconductor