FIDO1100 Innovasic Semiconductor Inc., FIDO1100 Datasheet - Page 49

• Manufacturer Part Number: FIDO1100
• Description: 32-bit Real-time Communications Controller
• Manufacturer: Innovasic Semiconductor Inc.

Flexible Input Deterministic Output (fido ® )
32-Bit Real-Time Communications Controller
6.
Thermal resistance represents the capability of an IC package to carry out the heat inside an IC
chip. It is a complex function of package structure, material property, input power, and
environment variables such as airflow speed and PCB layers that can be analyzed by finite
element modeling (FEM) techniques. In the simulations used to generate information for this
data sheet, a commercial Finite Element Analysis (FEA) program, ANSYS, was used to create
the 3D thermal model stacked by brick elements. Considering the package structure symmetry,
only the quarter package structure was modeled to save CPU calculating time. All the materials
were assumed isotropic with constant physical property and all material interfaces are also
assumed perfect joined. The heat flux was applied on the top surface of the die to simulate
heating power and constant convection coefficients were applied on the exterior surface of this
model. The physical properties and simulation conditions are summarized in Table 16.
Table 16. Physical Properties and Simulation Conditions
The thermal characteristic listed in this data sheet address both the 28- by 28-mm PQFP and the
BGA 10- by 10-mm package mounted on four layers of PCB using the Finite Element Modeling
(FEM) method. The junction-to-ambient thermal resistance is used to evaluate thermal
performance for this package and then to predict the power dissipation capability by given
ambient and maximum junction temperatures.
The results shown in Figure 8 are generated using the input power (P) and ambient temperature
(T
temperature of 65°C, maximum junction temperature of 125°C, and input power of 1 watt. The
maximum power dissipation of the PQFP and BGA packages is:
Test Board (PCB)
Control Condition
A
), to calculate the thermal resistance of θ
Input Power
Thermal Characteristics
Four Layer (2S2P)
Air flow = 0,1,2, and 3 M/S
®
1.0W
UNCONTROLLED WHEN PRINTED OR COPIED
JA
Page 49 of 83
according to θ
IA211080807-07
JA
= (T
J
– T
A
)/P, assuming ambient
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April 15, 2010
Data Sheet
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