ADSP-21262 Datasheet, PDF (38/44 Pages) Analog Devices – SHARC Processor

ADSP-21262
7
6
5
4
3
2
1
0
-1
-2
-3
-4
0
y = 0.0904x - 2.712
20
40
60
80
100
120
LOAD CAPACITANCE (pF)
Figure 33. Typical Output Delay or Hold vs. Load Capacitance
(at Ambient Temperature)
ENVIRONMENTAL CONDITIONS
The ADSP-21262 processor is rated for performance over the
commercial temperature range, T_AMB = 0°C to 70°C.
THERMAL CHARACTERISTICS
Table 32 and Table 33 airflow measurements comply with
JEDEC standards JESD51-2 and JESD51-6 and the junction-to-
board measurement complies with JESD51-8. The junction-to-
case measurement complies with MIL-STD-883. All measure-
ments use a 2S2P JEDEC test board.
To determine the Junction Temperature of the device while on
the application PCB, use:
T_J = T_CASE + (Ψ_JT × P_D)
where:
T_J = Junction temperature °C
T_CASE = Case temperature (°C) measured at the top center of the
package
Ψ_JT = Junction-to-Top (of package) characterization parameter
is the Typical value from Table 32 and Table 33.
P_D = Power dissipation (see EE Note #216)
Values of θ_JA are provided for package comparison and PCB
design considerations. θ_JA can be used for a first order approxi-
mation of T_J by the equation:
T_J = T_A + (θ_JA × P_D)
where:
T_A = Ambient Temperature °C
Values of θ_JC are provided for package comparison and PCB
design considerations when an external heat sink is required.
Values of θ_JB are provided for package comparison and PCB
design considerations.
Table 32. Thermal Characteristics for 136-Ball BGA¹
Parameter Condition
Typical Unit
θ_JA
Airflow = 0 m/s
28.2
°C/W
θ_JMA
Airflow = 1 m/s
24.4
°C/W
θ_JMA
Airflow = 2 m/s
23.3
°C/W
θ_JB
20.1
°C/W
θ_JC
7.0
°C/W
Ψ_JT
Airflow = 0 m/s
0.1
°C/W
Ψ_JMT
Airflow = 1 m/s
0.3
°C/W
Ψ_JMT
Airflow = 2 m/s
0.4
°C/W
1 _{The thermal characteristics values provided in this table are modeled values.}
Table 33. Thermal Characteristics for 144-Lead LQFP¹
Parameter Condition
Typical Unit
θ_JA
Airflow = 0 m/s
32.5
°C/W
θ_JMA
Airflow = 1 m/s
28.9
°C/W
θ_JMA
Airflow = 2 m/s
27.8
°C/W
θ_JC
7.8
°C/W
Ψ_JT
Airflow = 0 m/s
0.5
°C/W
Ψ_JMT
Airflow = 1 m/s
0.8
°C/W
Ψ_JMT
Airflow = 2 m/s
1.0
°C/W
1 _{The thermal characteristics values provided in this table are modeled values.}
Rev. A | Page 38 of 44 | May 2004