Datasheet

Rev. A | Page 52 of 80 | July 2011
ADSP-BF504/ADSP-BF504F/ADSP-BF506F
PROCESSOR—ENVIRONMENTAL CONDITIONS
To determine the junction temperature on the application
printed circuit board use:
where: T
J
= junction temperature (°C).
T
CASE
= case temperature (°C) measured by customer at top cen-
ter of package.
Ψ
JT
= from Table 43 and Table 44.
P
D
= power dissipation (see Total Power Dissipation on Page 29
for the method to calculate P
D
).
Values of θ
JA
are provided for package comparison and printed
circuit board design considerations. θ
JA
can be used for a first
order approximation of T
J
by the equation:
where T
A
= ambient temperature (°C)
Values of θ
JC
are provided for package comparison and printed
circuit board design considerations when an external heat sink
is required.
Values of θ
JB
are provided for package comparison and printed
circuit board design considerations.
In Table 43 and Table 44, 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 (Method
1012.1). All measurements use a 2S2P JEDEC test board.
Figure 47. Driver Type C Typical Rise and Fall Times (10%–90%) vs.
Load Capacitance (1.8 V V
DDEXT
)
Figure 48. Driver Type C Typical Rise and Fall Times (10%–90%) vs.
Load Capacitance (2.5 V V
DDEXT
)
Figure 49. Driver Type C Typical Rise and Fall Times (10%–90%) vs.
Load Capacitance (3.3 V V
DDEXT
)
15
RISE AND FALL TIME (ns)
LOAD CAPACITANCE (pF)
0 50 100 150 250
25
20
0
5
10
200
t
RISE
t
FALL
t
RISE
= 1.8V @ 25 ° C
t
FALL
= 1.8V @ 25 ° C
8
RISE AND FALL TIME (ns)
LOAD CAPACITANCE (pF)
0 50 100 150 250
16
12
0
2
4
10
200
t
RISE
t
FALL
6
14
t
RISE
= 2.5V @ 25 ° C
t
FALL
= 2.5V @ 25 ° C
6
RISE AND FALL TIME (ns)
LOAD CAPACITANCE (pF)
0 50 100 150 250
14
12
0
2
4
8
200
t
RISE
t
FALL
t
RISE
= 3.3V @ 25 ° C
t
FALL
= 3.3V @ 25 ° C
10
Table 43. Thermal Characteristics (88-Lead LFCSP)
Parameter Condition Typical Unit
θ
JA
0 linear m/s air flow 26.2 °C/W
θ
JMA
1 linear m/s air flow 23.7 °C/W
θ
JMA
2 linear m/s air flow 22.9 °C/W
θ
JB
16.0 °C/W
θ
JC
9.8 °C/W
Ψ
JT
0 linear m/s air flow 0.21 °C/W
Ψ
JT
1 linear m/s air flow 0.36 °C/W
Ψ
JT
2 linear m/s air flow 0.43 °C/W
Table 44. Thermal Characteristics (120-Lead LQFP)
Parameter Condition Typical Unit
θ
JA
0 linear m/s air flow 26.9 °C/W
θ
JMA
1 linear m/s air flow 24.2 °C/W
θ
JMA
2 linear m/s air flow 23.3 °C/W
θ
JB
16.4 °C/W
θ
JC
12.7 °C/W
Ψ
JT
0 linear m/s air flow 0.50 °C/W
Ψ
JT
1 linear m/s air flow 0.77 °C/W
Ψ
JT
2 linear m/s air flow 1.02 °C/W
T
J
T
CASE
Ψ
JT
P
D
×()+=
T
J
T
A
θ
JA
P
D
×()+=