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AD9520-2
Data Sheet
Rev. A | Page 60 of 80
THERMAL PERFORMANCE
Table 49. Thermal Parameters for 64-Lead LFCSP
Symbol
Thermal Characteristic Using a JEDEC JESD51-7 Plus JEDEC JESD51-5 2S2P Test Board
Value (°C/W)
θJA
Junction-to-ambient thermal resistance, 0.0 m/sec airflow per JEDEC JESD51-2 (still air)
22.0
θJMA
Junction-to-ambient thermal resistance, 1.0 m/sec airflow per JEDEC JESD51-6 (moving air)
19.2
θJMA
Junction-to-ambient thermal resistance, 2.0 m/sec airflow per JEDEC JESD51-6 (moving air)
17.2
ΨJB
Junction-to-board characterization parameter, 1.0 m/sec airflow per JEDEC JESD51-6 (moving air)
and JEDEC JESD51-8
11.6
θJC
Junction-to-case thermal resistance (die-to-heat sink) per MIL-Std 883, Method 1012.1
1.3
ΨJT
Junction-to-top-of-package characterization parameter, 0 m/sec airflow per JEDEC JESD51-2 (still air)
0.1
The AD9520 is specified for a case temperature (TCASE). To ensure that TCASE is not exceeded, an airflow source can be used.
Use the following equation to determine the junction
temperature on the application PCB:
TJ = TCASE + (ΨJT × PD)
where:
TJ is the junction temperature (°C).
TCASE is the case temperature (°C) measured by the user at the
top center of the package.
PD is the power dissipation (see the total power dissipation in
Values of θJA are provided for package comparison and PCB
design considerations. θJA can be used for a first-order
approximation of TJ by the equation
TJ = TA + (θJA × PD)
where TA is the ambient temperature (°C).
Values of θJC are provided for package comparison and PCB
design considerations when an external heat sink is required.
Values of ΨJB are provided for package comparison and PCB
design considerations.