ADSP-21062/ADSP-21062L
ENVIRONMENTAL CONDITIONS
9
8
Thermal Characteristics
The ADSP-21062 is available in 240-lead thermally enhanced
MQFP and 225-lead plastic ball grid array packages. The top
surface of the thermally enhanced MQFP contains a copper slug
from which most of the die heat is dissipated. The slug is flush
with the top surface of the package. Note that the copper slug is
internally connected to GND through the device substrate.
7
6
Y = 0.0391X + 0.36
5
4
RISE TIME
Y = 0.0305X + 0.24
Both packages are specified for a case temperature (TCASE). To
ensure that the TCASE is not exceeded, a heatsink and/or an air
flow source may be used. A heatsink should be attached with a
thermal adhesive.
3
2
1
0
FALL TIME
T
CASE = TAMB + ( PD × θCA
)
0
20
40
60
80 100 120 140 160 180 200
T
PD =
CASE = Case temperature (measured on top surface of package)
LOAD CAPACITANCE – pF
Power dissipation in W (this value depends upon the
specific application; a method for calculating PD is
shown under Power Dissipation).
Figure 34. Typical Output Rise Time (0.8 V–2.0 V) vs.
Load Capacitance (VDD = 3.3 V)
θCA
=
Value from table below.
5
240 MQFP
4
3
2
1
Y = 0.0329X –1.65
JC = 0.3؇C/W
Airflow
(Linear Ft./Min.)
0
100
200
400
600
θ
CA (°C/W)
10
9
8
7
6
NOTES
This represents thermal resistance at total power of 5 W.
With air flow, no variance is seen in θCA with power.
θ
CA at 0 LFM varies with power: at 2W, θCA = 14°C/W, at 3W θCA = 11°C/W.
NOMINAL
225 PBGA
–1
25
50
75
100
125
150
175
200
LOAD CAPACITANCE – pF
JC = 1.7؇C/W
Airflow
(Linear Ft./Min.)
Figure 35. Typical Output Delay or Hold vs. Load Capaci-
tance (at Maximum Case Temperature) (VDD = 3.3 V)
0
200
400
θ
CA (°C/W)
20.7
15.3
12.9
NOTE
No variance is seen in θCA with power.
REV. C
–43–
ADI [ ADI ]
